Backup server (old)

amanda.conf

• dumptypes
• dumpcycle
• estimate timeouts
• Tapetype definitions

Exclude lists

There are three ways of excluding data in an AMANDA backup:

• Exclude an individual item explicitly in the dumptype
• Utilize an "Exclude List"
• Do not include the data in the disklist

The only way to exclude files or directories with AMANDA is to use GNU-tar as the dump program (others?). The file system dump programs provided with unix systems (e.g. dump, ufsdump) get data at a raw drive level and generally do not allow exclusion of specific files or directories.

The GNU version of tar, (GNU-tar or gtar), reads its data at a file system, (or higher), level and does include the option to exclude specific files and/or directories. It should be mentioned here that tar will change the access times on files. Tar has the ability to preserve the access times however, doing so effectively disables incremental backups since resetting the access time alters the inode change time, which in turn causes the file to look like it needs to be archived again.

For the purpose of this document an AMANDA backup configuration named "exclude-test" will be used. The machine that contains the tape drive which receives data to be archived will be referred to as "SERVER". The machine that data is being archived from will be referred to as "CLIENT". These two systems are usually different machines but are not required to be, and may be the same machine. Parts of this setup are on the server and some are on the client.

When AMANDA attempts to exclude a file or directory it does so relative to the area being archived. For example if /var is in your disklist and you want to exclude /var/log/somefile, then your exclude file would contain ./log/somefile.

You may use one exclude file in multiple dumptypes without any restriction.

Before We Begin

• The first step that should be taken is to verify that backups are currently working. Connect to SERVER and run amcheck as your AMANDA user, to verify that there are no errors in the current setup.

$ amcheck -cl CLIENT

Output should look something like below for success:

       AMANDA Tape Server Host Check
       -----------------------------

       /path/to/holding-disk: 4771300 KB disk space available, that's plenty.  
       AMANDA Backup Client Hosts Check
       -------------------------------- 
       Client check: 1 host checked in 0.084 seconds, 0 problems found.

• Next make sure that GNU-tar is the dump program currently in use. The easiest way to tell if your dumptype is using gnutar is to run the following:

$ amadmin exclude-test disklist CLIENT

Among all the output is the "program" value currently in use. This value is also specified with the "program" option in the dumptype. If the dumptype has the line "program GNUTAR" your setup should be ready to exclude data.

If GNU-tar is not in use add the line "program GNUTAR" to the dumptype, and then run amcheck again to verify that backups should work. The capitalization of GNUTAR is required.

The dumptype should look something like:

define dumptype exclude-test {
      comment "test dumptype for documentation"
      priority high
      program "GNUTAR"
}

Choosing an exclude mechanism

If the need is to exclude only one file or directory then the easiest way to accomplish this is to exclude an individual item explicitly in the dumptype. If the need is to exclude multiple files or directories then use an Exclude List.

Exclude Mechanisms

Exclude an individual item explicitly in the dumptype

The easiest way to exclude a file or directory is to specify it with the "exclude" option in the dumptype. This option accepts an argument of the file or directory to be excluded. AMANDA allows only one exclude option in any dumptype at a time.

UPDATE: Recent AMANDA-releases bring the option "exclude append" which enables the administrator to define more than 
one exclusion-pattern within one dumptype without using a exclude-list. Please look at the amanda.conf manpage for details.

Any path specified to be excluded must be encapsulated with quotes. Continuing with our example from above /var/log/somefile and using the same dumptype as above, the dumptype would now look like:

define dumptype exclude-test {
     comment "test dumptype for documentation"
     priority high
     program "GNUTAR"
     exclude "./log/somefile"
}

Next run amcheck again to verify that there are no problems with the revised AMANDA configuration. If the data is not being excluded as expected please see the Troubleshooting section below. This completes the setup of excluding an individual item in the dumptype.

Utilize an Exclude List

An exclude list is a file that resides on the CLIENT machine and contains paths to be excluded, one per line. This file can be in any location on the CLIENT so long as the same path is specified in the dumptype. Some find /usr/local/etc/amanda an appropriate location, but it is up to you. I personally like to have a subdirectory for exclude files but it is up to you where you place this file.

The exclude file may also be placed in the area being archived. This is an easy way to have a different exclusion file for each disklist entry without needing separate dumptype definitions. To use this technique, enter a path relative to the area being archived as the exclude file below instead of an absolute path.

Connect to CLIENT and create the exclude directory as root. For example:

$ mkdir -p /usr/local/etc/amanda/exclude
$ cd /usr/local/etc/amanda/exclude

Next create the exclude list for AMANDA to use. You can name the exclude file anything you wish it to be. Create a file, and in this file place all paths to files and directories that are to be excluded. Keeping with the /var example, assume that /var/log/XFree86.0.log, and /var/log/maillog need to be excluded. Remember that all paths are relative. The exclude list would look like:

./log/XFree86.0.log
./log/maillog

Make sure that permissions are restricted on this file. Run the following as root, where exclude-filename is the name of the file you just created. For example:

$ chmod 644 /usr/local/etc/amanda/exclude/exclude-filename

This concludes the necessary configuration on the client.

Connect to SERVER and cd to the exclude-test AMANDA configuration directory. Edit the AMANDA configuration file e.g. amanda.conf. Add an entry similar to the following line, to the dumptype for the client in question, where the exclude-filename is the file that was created on CLIENT in the step above including the quotes. For example:

exclude list "/usr/local/etc/amanda/exclude/exclude-filename"

The new dumptype should look something like:

define dumptype exclude-test{
  comment "test dumptype for documentation"
  priority high
  program "GNUTAR"
  exclude list "/usr/local/etc/amanda/exclude/exclude-filename"
}

Save the file. Run amcheck again to verify that there are no problems with the revised AMANDA configuration. If amcheck succeeds then run amdump to verify the data is being excluded correctly. If the data is not being excluded as expected please see the Troubleshooting section below. This completes the setup of an exclude list.

Do not include the data in the disklist

AMANDA uses disklist entries to define which directories or partitions should be archived. This allows us to exclude data by just not placing the data in question in the disklist. Assume that there is a disk mounted on /example. The directory /example has five subdirectories "a", "b", "c", "d", and "e". The directories "a", "b", and "c" need to be archived, while "d" and "e" should not. This can be accomplished by not specifying "d" and "e" in the disklist. Using the same dumptype and host in the above examples the disklist would contain:

CLIENT /examples/a	exclude-test
CLIENT /examples/b	exclude-test
CLIENT /examples/c	exclude-test

Run amcheck to verify that AMANDA is working correctly. If the data is not being excluded as expected please see the Troubleshooting section below. This completes the setup of using a disklist to exclude data. Expression

Quiz: what is the difference between the following entries in an exclude list?

./foo
./foo/
./foo/*

case 1 : directory ./foo won't be in the backup image (that's what you want) case 2 : matches nothing (don't use it) case 3 : directory ./foo will be in the backup image but nothing below it.

Wildcard Expansion

AMANDA has the ability to use wildcard expansion while excluding data as implemented by tar(1). The only places that wildcard expansion is allowed is in the "exclude" option in the dumptype, or in the exclude list. Some simple examples:

./*.log

Exclude any file or directory that ends in ".log" e.g. ppp.log, XFree86.0.log

*/*log*

Exclude any file or directory with the string "log" e.g. logfile, maillog, syslog, ppp.log, XFree86.0.log

./cron*.gz

Exclude any file or directory that starts with string "cron" and ends in ".gz" e.g. cron.1.gz, cron.2.gz, log/cron.1.gz

./log.?

The question mark can be used to specify a single character. e.g. log.1, log.2, etc

Troubleshooting

If you find that you are having trouble getting the exclude patterns to match correctly, check out this really cool script written by John R. Jackson.

ftp://gandalf.cc.purdue.edu/pub/amanda/gtartest-exclude

This script allows you to test your patterns before placing them in an exclude list or in the dumptype. Instructions on how to run the script are included in the script.

Broken gnutar?

There are versions of GNU-tar that do not correctly exclude data. Version 1.12 (plus the AMANDA patches from http://www.amanda.org) are known to work correctly, as does version 1.13.19 (and later). Anything else is questionable.

UPDATE: Using GNU-tar 1.13.25 is recommended.

Connect to CLIENT and run a ps command and look to see exactly how the tar command is running. Look in the output for the --exclude or --exclude-from options in the running tar process. For example:

$ ps ax | grep tar 

?        R      0:37 /bin/tar --create --directory /var
--listed-incremental /var/lib/amanda/gnutar-lists/CLIENTvar_0.new
--sparse --one-file-system --ignore-failed-read --totals --file
/dev/null --exclude-from=/usr/local/etc/amanda/exclude-test/exclude.var
.

In the above output notice the string "--exclude-from=". The string following the "=" is the exclude file currently in use. If the string was "--exclude" then the string following the "=" is the file or directory that is currently set to be excluded.

Device configuration

Tapetypes

Tapetype definitions are specified in amanda.conf configuration file. The tapetype definition provides AMANDA how much it is supposed to be able to store in a tape (length), how much space is wasted at the end of a dump image with the EOF mark (filemark) and how fast the tape unit is (speed).

The most important parameter is length, since AMANDA may decide to delay a backup if length is too small, but, if it is too large, AMANDA may end up leaving dumps in the holding disk or having to abort some dump.

Filemark is important if you have many disks, particularly with small incremental backups. The space wasted by so many filemarks may add up and considerably modify the available tape space.

The speed is currently unused.

AMANDA provides the amtapetype utility to calculate the size of a tape, to generate a "tapetype" entry for your amanda.conf.

Specifying the appropriate tape device, but beware that it may take many hours to run (it fills the tape twice ...). Make sure you do not use hardware compression, even if you plan to use hardware compression in the future. amtapetype writes random data to tape, and random data will expand instead of compressing, therefore you'll get an estimate that's smaller than expected.

Some tapetype definitions are available here.

Changers

Introduction

This document outlines the tape changer support design of AMANDA 2.2 and beyond. It defines a small interface for changer software to follow so that AMANDA can remain device-independent but still support the widest range of tape software and hardware possible. The interface is a bit simplistic and has only had complications added when there is a body of field experience.

Specifying a tape changer in amanda.conf

All device-specifics are hidden by a glue program that the rest of AMANDA calls to interact with the tape changer.

The name of this changer program is given by the "tpchanger" variable in the file amanda.conf. Example entry:

tpchanger "chg-multi"	   # use multi-unit tape changer emulator

The tapedev parameter is ignored if a tpchanger program is specified, unless the changer program itself reads tapedev from amanda.conf. The chg-multi changer doesn't, as it reads all its configuration arguments from its own configuration file, specified as changerfile.

If the tpchanger program does not begin with a '/', AMANDA expects it to reside in libexecdir, and possibly have the version suffix appended depending on how AMANDA was configured.

Two other amanda.conf parameters are available for changer use, however their definition is left entirely up to the changer script itself. They are changerfile and changerdev. Typically changerfile will point to the configuration file specific to the changer, or be a base name of several related changer files. The changerdev variable may point to the /dev entry used to access the changer device.

See the documentation with the specific changer you're interested in to see exactly how these variables are used (if at all).

Device-specific tapechanger script

The tape changer script/program is always from the directory with amanda.conf. It is never passed the configuration name it is running on behalf of, but since amgetconf works without a name from the current directory, that should be sufficient.

The script/program must support the following commands:

<tpchanger> -slot <slot-specifier>

If changer is loaded, unloads the current slot (if different than "slot-specifier") and puts that tape away, then loads the requested slot. See the next section for the list of valid slot requests.

Outputs to stdout the slot name and name of the device file to access the tape on success, or a slot name and error text.

Returns 0 on success.

Returns 1 on positioning error (eg at bottom of gravity stacker or slot empty).

Returns 2 any other fatal error. The slot name may be invalid, but must be present. Error message goes to stdout in place of device name.

Examples:

% chg-multi -slot 0
0 /dev/nrst8			# exitcode returned is 0

% chg-multi -slot 1
1 slot 1 is empty		# exitcode returned is 1

% chg-multi -slot bogus-slot
<none> no slot `bogus-slot'	# exitcode returned is 2

<tpchanger> -info

Outputs to stdout three or more fields:

• The current slot string (required)
• The number of slots (required)
• Flag indicating whether the changer can go backward (0 if it can't, 1 if it can). (required)
• Flag indicating whether the changer is searchable
• (optional). Shows whether the changer supports the -search and -label commands and is able to load a tape given only the AMANDA label string (0 or omitted if it can't, 1 if it can). (optional)

Examples:

% chg-multi -info
0 10 1				# exitcode returned is 0

% chg-zd-mtx -info
0 10 1 1 

<tpchanger> -reset

Resets the changer to known state and loads the first slot.

Output and error handling are the same as "<tpchanger> -slot first"

In the case of a gravity stacker that must be reset by hand, this could be run (via " amtape <conf> reset") to inform the software the stacker is positioned back at the top.

Examples:

% chg-multi -reset
0 /dev/nrst8			# exitcode returned is 0

% chg-multi -reset
0 slot 0 is empty		# exitcode returned is 1

% chg-multi -reset
0 tape-changer not responding	# exitcode returned is 2 

<tpchanger> -eject

Unloads the current slot (if loaded) and puts that tape away.

Output and error handling are the same as the -slot command. Note that a tape may or may not be loaded when this command completes, depending on the hardware.

Examples:

% chg-multi -eject
0 /dev/nrst8			# exitcode returned is 0

% chg-multi -eject
0 drive was not loaded		# exitcode returned is 1 

The tape changer program MAY support the following commands:

<tpchanger> -search <labelstr>

Loads an AMANDA tape by name (labelstr).

Output and error handling are the same as the -slot command. taper, amcheck and amtape will use this command if the changer reports it is searchable.

Example:

% chg-zd-mtx -search DailySet005
5 /dev/nrst8			# exitcode returned is 0 

<tpchanger> -label <labelstr>

Associates the AMANDA label <labelstr> with the barcode of the currently loaded (in the tape drive) tape.

Outputs to stdout the current slot and tape device. amlabel will use this command if your changer is searchable to build up the barcode database.

Example:

% chg-zd-mtx -label DailySet006
6 /dev/nrst8			# exitcode returned is 0 

For all the commands

An exit code of 0 implies that the operation was completely successful, and the output may be parsed by the AMANDA code as described above.

For non-zero exit codes, the first field is still the slot name, but the actual error messages are not fixed. They are just displayed and/or logged as-is by the calling AMANDA program.

An exit code of 1 implies the operation failed in a benign way, for example an empty slot or an attempt to go backwards in a gravity stacker. The calling AMANDA program will print the error message if appropriate and continue, perhaps requesting a different slot be loaded.

Any other exit code is considered fatal and will cause AMANDA to stop attempting to talk to the tape changer.

Slot names and the "current" slot

Some tape changers, such as carousels and gravity stackers, have a hardware notion of current position. Others have no current position when no tape is loaded: all tapes are in their slots and the changer arm is docked away from the slots.

Nevertheless, AMANDA requires tape-changer scripts to maintain the notion of a "current" position. This is for performance reasons: as tapes tend to be loaded into the rack in order, and AMANDA uses them in order, the next tape to use can be found much quicker if the position of the current one is remembered. As an example, the chg-multi script maintains the current position in a chg-multi.state file (or any other file specified in a `statefile' line in the changer configuration file).

AMANDA does not care how slots are available or how they are named. They could be numbered 0 to N-1, numbered 1 to N, or even designated by letter, A .. Z. The only requirement is that the names do not contain whitespace and that the names "current", "next", "prev", "first", "last" and "advance" retain their meaning as follows:

• current - The position of the last loaded tape, as described above
• next - The position after current, wrapping from the last slot to the first.
• prev - The position before current, wrapping from the first slot to the last.
• first - The first slot in the tape rack.
• last - The last slot in the tape rack.
• advance - The same as "next" except the next tape may not be loaded if the changer supports advancing to the next slot without putting that tape in the drive.

The current position must be updated even if there is a positioning error (such as "empty slot"). This allows amanda to step through the entire tape rack by issuing successive "slot next" positioning commands.

Operator interface

The amtape program is the main operator interface to AMANDA's tape changer support. The commands supported include:

amtape <conf> slot <slot-specifier>

Load the tape from the specified slot into the drive

amtape <conf> eject

Send an eject command to the tape-changer. Effect is changer specific.

amtape <conf> reset

Send a reset command to the tape-changer. Effect is changer specific.

amtape <conf> show

Go through the entire tape rack, showing the labels of all amanda tapes encountered.

amtape <conf> label <label>

Find and load the tape with the specified label

amtape <conf> taper

Perform taper's scan algorithm (see below), loading the tape which would be picked for the next amdump run.

amtape <conf> clean

If a cleaning tape is defined by the changer, load it in the drive and put it away when done.

amtape <conf> device

Output the current tape device name.

amtape <conf> current

Display the contents of the current slot.

amtape <conf> update

Scan the entire tape rack and update the barcode database.

See the amtape(8) man page for more details.

In addition to amtape, amlabel has been modified to allow optionally specifying a slot:

amlabel <conf> <label> [slot <slot-specifier>]

amcheck looks for the next tape in the rack the same way the taper does. If multiple tapes are used in one night, amcheck attempts to find all the needed tapes in turn if the tape-changer is random access. On a one-way gravity stacker, amcheck only finds the first tape, since finding the subsequent ones would put the first one out of reach of that night's amdump run.

amrestore and amrecover do not yet include any tape changer support directly, as amrestore knows nothing about the amanda.conf files or server-side databases. This is a deliberate decision to keep amrestore independent, so it can be run from any host with a tape drive, even if the original tape server host is down. To use amrestore in a tape-changer environment, use amtape to find the right tape, then run amrestore giving the resulting tape device name.

How amdump interacts with the tape changer

AMANDA does not require a particular tape label for a run. Any label that matches the labelstr regex and is determined to be "inactive" according to the tapelist database, may be written to. However, there is a preferred 'next' tape, the one that is next in the cycle implied by the current tapelist.

amdump uses two algorithms, depending on whether the tape changer can go backwards in the rack or not. If multiple tapes are needed in a single run, this algorithm is repeated in turn whenever a new tape is required.

Normal tape changers (those that can go backwards)

With a full-access tape changer, amdump searches the entire rack for the preferred tape label. This tape will usually be found at the current or next position, but might be located anywhere. If the tape is found, it is used. If it is not found, the first tape encountered that matches the labelstr and is not active is picked.

Gravity stackers (anything that can not go backwards)

To avoid going all the way to the bottom of the stacker only to find that the preferred tape isn't present and nothing can be done, AMANDA picks the first tape (starting at the current position) that matches the labelstr and is not active, regardless of whether it is the preferred tape.

Builtin tape-changers

chg-multi (formerly chg-generic)

This tape changer script supports several common configurations:

• Using multiple tape drives in a single host to emulate a tape changer. This can also be used with a single physical drive to write several tapes in an AMANDA run.
• Using a gravity stacker or a real changer configured to sequentially load the next tape when the current one is ejected. Also supports a changer which cycles to the first tape after loading the last one.
• Using a changer accessed through several "virtual" tape devices which determine which slot actually gets loaded in the tape drive.

The advantage of this changer script is that you do not need to get into the complexity of dealing with a real changer interface. All the action goes through the tape device interface with standard mt commands, which eases many portability issues. Many common tape jukeboxes can be configured in a sequential or cycle mode.

chg-multi ignores `tapedev' and `changerdev' because `changerfile' may specify several tape devices to be used. A sample configuration file may be found in example/chg-multi.conf.

chg-manual (formerly no-changer)

This is a poor man's tape changer that requires the backup operator to change tapes manually. It expects `tapedev' in amanda.conf to point to a valid tape device, and stores some status data in files whose names start with the `changerfile'. `changerdev' is ignored.

chg-mtx (formerly hp-changer)

An mtx-based tape changer script. `changerdev' must specify the tape device controlled by the mtx program, and `tapedev' must point to the no-rewind tape device to be used. More than likely, both `changerdev' and `tapedev' will reference the same device file. `changerfile' must specify a prefix for status files maintained by this script. It will maintain files named `changerfile'/changer-clean and `changerfile'/changer-access. You may have to edit the script to specify which slot contains a cleaning tape (cleanslot).

The mtx program must support commands such as `-s', `-l' and `-u'. If the one you've got requires `status', `load' and `unload', you should use chg-zd-mtx instead (see below).

chg-zd-mtx

Based on chg-mtx, but modified in order to support the Zubkoff/Dandelion version of mtx. Eric DOUTRELEAU <[email protected]>, who contributed this script, reported that it works on a Solaris/sparc box with a HP 1557A stacker.

In addition to the `changerfile'-clean and the `changerfile'-access files, it maintains a `changerfile'-slot file that indicates the currently loaded slot.

There are lots of comments at the start of the script describing how to set it up.

chg-scsi-chio (formerly seagate-changer, then chg-chio)

A C program that relies on scsi tape-changer interfaces. It may either use the tape changer interface specified in chio.h (Gerd Knor's SCSI media changer driver, a Linux kernel loadable module), or it may use built-in tape changer interfaces available on HPUX, Solaris 2.5, IRIX and possibly others, but only the chio and HPUX interfaces are currently implemented . `tapedev' specifies the tape device to be used; `changer_dev' is the device used to talk to the kernel module (for chio, usually /dev/ch0), and `changerfile' specifies a filename in which the current slot number will be stored.

Now there is another way, to get the chg-scsi a little bit more flexible. If you use only one digit in the `tapedev' parameter, the chg-scsi expects that changerfile points to a real configuration file, not only a counting file. In this configuration file you may specify that the tapedrive needs an eject command and an optional waittime, necessary after inserting the tape into the drive. You are also able to configure a range of slots which should be used by your configuration. The idea behind this is, that you don't want AMANDA to cycle all the tapes if AMANDA searches exactly one tape. If you have a library which supports more than one drive you can also specify which drive to use. For each configuration (there should be at least one) you have to specify a file, where AMANDA remembers which tape is actually in the drive. For future use there is also some stuff for cleaning the drives.

In amanda.conf:

tapedev "x"       with x between 0 and 9, selects the configuration to use
changerfile "filename"            specifies the changer configuration file

In the changer-config-file the following could be set:

number_configs x
#	x between 0 and 9 	number of configurations defined. This should be the first parameter in the config-file.
eject	x
#	x 0 or 1		1 means that the drives need an eject command, before the robot can handle the tape.
sleep	x
#	x between 0 and MAX_INT specifies the seconds to wait before the drive could be used after inserting a tape. 5 should be OK.
cleanmax x	
#	x some positive int	How many cleanings does a cleaning tape survive
changerdev  <device>
#				The device for the robot

And then there come some configuration sections, separated by the word `config` followed by the ordinal of that configuration (0 to 9). In each configuration section you should specify:

drivenum x		x between 0 and the number of drives in the library
This one specifies the drive to use with this configuration
dev	<device>				The device for the tapedrive
startuse    x		x between 0 and maximum slotnumber of your library
Starting here we may use the tapes
enduse	 x		x between start and maximum slotnumber
This is the last tape we may use in this configuration. If we reach this one the next will be start..
statfile <filename>				Here we remember the last used
slot for this configuration
cleancart	x	x between 0 and maximum slotnumber 
In this slot we find the cleaning tape
cleanfile <filename>				
Here we will remember how often we used the cleaning tape
usagecount <filename>				This points to a file which is deleted after cleaning the drive
                                               e.g. the usagetime of the drive

Comments begin with an '#' until end of line. Allowed separators are TAB and SPACE.

chg-scsi (new interface, try to drive a robot with direct scsi commands)

The config and the syntax is the same as for chg-scsi-chio. New is the config type

emubarcode 1

With this option and the option labelfile chg-scsi will try to create an inventory. With this inventory it should be possible to use the search feature for loading tapes.

debuglevel x:y

This option will set the debug level and select for which part debug messages should be sent to the debug file. In case of problems you should set it to 9:0

havebarcode 1

This will force the program to read the barcodes, and don not try to figure out if there is an barcode reader available.

scsitapedev <devicename>

This device is used to control the tape, read status infos etc.

tapestatus <filename>

If this option is given on every eject/move the log pages of the tape device will be dumped in this file. There are 2 log pages were you can see how many read/write errors (corrected) are processed by the tape

labelfile <filename>

This file is used for the mapping from barcode labels to AMANDA volume labels. It is used if the changer has a barcode reader. To initialize run amtape show, this will add the mapping for the tapes in the magazine.

eject > 1

Use the mtio ioctl to eject the tape, use only if the standard (1) does not work, and send the debug output (/tmp/amanda/chg-scsi.debug) to [email protected]

changerident <ident>

With this it is possible to specify which internal driver to use for controlling/error handling of the robot

tapeident <ident>

Same as above but for the tape.

New command line option: -status [all|types|robot|sense|ModeSenseRobot|ModeSenseTape|fd]

<all> will show the result form all options. <types> will list the known driver types. <robot> will show the status of all elements (tape/robot/slots..) <sense> will show the result from a request sense <ModeSenseRobot> will show the sense page from the robot <ModeSenseTape> will show the sense page from the tape <fd> will show the devices which are open, and some info about it.

At the moment changer with tape and robot on the same SCSI id ( but on different luns) will run on the following platforms:

• HP_UX 10.20
• IRIX 6.x
• Solaris
• Linux
• AIX
• FreeBSD 3.0/4.0

Tape and robot on different IDs run native on

• Linux
• HP-UX 10.20
• Irix 6.x
• FreeBSD

Solaris

Tape and robot on different IDs with special modules run on: Solaris with sst kernel module, which is not any longer needed in solaris 2.8. See in the contrib/sst directory The configuration on solaris 2.8 with the sgen driver is done by creating the file /kernel/drv/sgen.conf

This file should contain at the beginning the following device-type-config-list="changer","sequential"

This will force the driver to attach only to the devices with type either changer (the robot) and sequential (the tape). Next you must tell the driver on which id it should check for devices (tape on id 5, robot on id 6 in this example),

name="sgen" class="scsi" target=5 lun=0; name="sgen" class="scsi" target=6 lun=0;

This will create the 2 device files /dev/scsi/sequential/c0t5d0 (scsitapedev option in chg-scsi.conf) /dev/scsi/changer/c0t6d0 (changer option in chg-scsi.conf)

So the complete sgen.conf looks like: device-type-config-list="changer","sequential name="sgen" class="scsi" target=5 lun=0; name="sgen" class="scsi" target=6 lun=0;

HP

You have to create the special device files for the pass throu interface. Check if the ctl driver is installed. Example:

# lsdev -C ctl
 Character     Block       Driver          Class
    203          -1         sctl            ctl

Next check on which bus your drives are connected. (ioscan) with the Character device num form the lsdev and the card instance from ioscan create the special file. Example:

mknod /dev/scsi/1 c 203 0x001000
                          ||||
                          ||| LUN of device
                          ||SCSI ID of the device
                          2 digit instance number from ioscan

FreeBSD 4.0

The syntax for the device files has changed. Now you have to tell chg-scsi the bus:target:lun combination. If you for example on your scsi bus 0 target 3 an robot the syntax is changerdev 0:3:0 To get this info you can use the camcontrol command, <camcontrl devlist> will give you a list of known devices. Don't specify dev and scsitapedev in your chg-scsi.conf !!, this will not work.

Linux

You need either sg (generic scsi) as module or it must be compiled into the kernel. If the sg driver doses not work try to use the ioctl interface. For that you have to undef the LINUX_CHG define in changer-src/scsi-linux.c Also you have to change the NORMAL_TIMEOUT in /usr/src/linux/drivers/scsi/scsi_ioctl.c from (10 * HZ) to (5 * 60 * HZ). On linux it does not run if you are using an aha1542 SCSI controller. The driver can not handle the extended request sense.

IRIX

You find the SCSI pass through interfaces for every device in /dev/scsi.

chg-scsi has been tested/run with the following devices: Exabyte 10h and eliant tape HP-Surestore 1200e and C1553A tape BreeceHill Q2.15 (EXB-120) and DLT7000 tape Powerstor L200 and DLT7000 ARCHIVE Python 28849-XXX TANDBERG TDS 1420 ADIC VLS DLT Library

It is now possible with a changer that has barcode reader to load tapes faster. Also amdump will find tapes faster. Every time a tape is labeled the information in the labelfile will be updated. To initialize the label mapping you can also do an amtape config show. This will put the mapping for all tapes in the magazine into the mapping file.

For all problems please contact [email protected]. Please include in your mail the debug file. (/tmp/amanda/chg-scsi.debug)

chg-chio

(new perl script that replaces the original chg-chio written in C) This script is based on the FreeBSD version of chio, a program to communicate with the jukebox. This script has for the moment only been test with FreeBSD and is likely not to work on any other system. Let me know if this is the case and send me the output of the chio program for your version of chio. It does not restrict the number of tapes, except that if there is only one tape in the juke, it is supposed to be in max_slot and not in slot 1. [This is the first version of the changer script and I would appreciate all comments on it, at [email protected]. It has been tested only with FreeBSD 2.2.5 and the accompanying chio program.]

chg-chs

(formerly chs-changer) A tape changer script very similar to chg-multi, that uses the `chs' program to change tapes. As in chg-multi, `tapedev' is ignored. `changerfile' names its configuration file, similar to chg-multi.conf. `changerdev' will be passed to CHS in a -f command-line switch, unless it is set to an empty string or "/dev/null" (watch out for default values!)

chg-rth

(formerly rth-changer) A perl5 script that controls an HPc1553 tape drive via a Peripheral Vision Inc. SCSI control subsystem that interprets commands sent on the SCSI bus. It expects `tapedev' to specify the tape device to be used. `changerfile' and `changerdev' are ignored.

chg-juke

A shell script that uses the Fermilab "juke" software (see http://www.fnal.gov/fermitools, the "juke" link) to control tape chagners. It supports mounting multiple tapes for RAIT tapedrive sets, both multiple jukeboxes, or one jukebox with multiple tape drives, or combinations. 'juke' must be configured to know tape drives by the same name AMANDA calls them. It uses 'changerfile' to track AMANDA's current tape state, 'tapedev' must be the tape drive (or RAIT set) name, and 'changerdev' is the juke software's name for the changer, or a csh-glob that expands to several jukebox names (i.e. "changer{a,b,c}").

chg-rait

A shell script that runs other changers in tandem, and returns a rait:{dev1,dev2,...} tape device based on the results of each other changer. So if you wanted to have 2 stackers striped with no parity, and you have chg-mtx support for your stackers, you would use the following changerfile:

  nchangers=3
  tpchanger_1="chg-mtx"
  changerdev_1="/dev/mtx1"
  changerfile_1="/some/file1"
  tapedev_1="/some/dev"
  tpchanger_2="chg-mtx"
  changerdev_2="/dev/mtx2"
  changerfile_2="/some/file2"
  tapedev_2="/some/dev"
  tpchanger_3="chg-null"
  changerdev_3="/dev/null"
  changerfile_3="/some/file3"
  tapedev_3="/some/dev"

The third uses the null changer. The tapedev_n entries are only needed if the changerfile in question uses them.

chg-disk

Clone of the chg-zd-mtx, but modified to be applied on local directories instead of tapes. This changer emulates a robotic that uses virtual tapes instead of real ones, where the virtual tapes are real directories on a hard disk.

The directory tree should be:

slot_root_dir -|
               |- info
               |- data -> slot1/
               |- slot1/
               |- slot2/
               |- ...
               |- slotn/

Where "slot_root_dir" is the tapedev "file:xxx" parameter and "n" the tapecycle parameter.

Please refer to How to use the AMANDA file-driver for details of usage.

chg-iomega

This changer script is designed for IOMEGA or JAZZ disks of various sizes as well as any other removable disk media. This is a PURELY MANUAL changer. It requests insertion of disk media via messages on /dev/tty. So it cannot be used via crontab. Make sure you comply with any of the following. - Add statements

       tpchanger "chg-iomega"
       tapedev "file:<mount_point_of_removable_disk>"
       (e.g. tapedev "file:/mnt/iomega" )
       tapetype IOMEGA      

       define tapetype IOMEGA {
           comment "IOMega 250 MB floppys"
           length 250 mbytes
           filemark 100 kbytes
           speed 1 mbytes
       }

to your amanda.conf. - Add entry to /etc/fstab to specify mount point of removable disk and make this disk mountable by any user. - Format all disks, add a "data" sub directory and label all disks by using amlabel. - Be aware that as of version 2.4.4p1, AMANDA can't handle backups that are larger than the size of the removable disk media. So make sure /etc/amanda/<backup_set>/disklist specifies chunks smaller than the disk size.

chg-null

A trivial changer which loads/unloads on a null: device. Useful with chg-rait to throw away a parity stripe by puttin on a null jukebox, or for testing.

RAIT

Currently it is only integrated with the chg-manual changer script

RAIT is an acronym for "Redundant Array of Inexpensive Tapes", where data is striped over several tape drives, with one drive writing an exclusive-or-sum of the others which can be used for error recovery. Any one of the data streams can be lost, and the data can still be recovered.

This means that a 3-drive RAIT set will write 2 "data" streams and one "parity" stream, and give you twice the capacity, twice the throughput, and the square of the failure rate (i.e. a 1/100 failure rate becomes 1/10,000, since a double-tape failure is required to lose data).

Similarly, a 5-drive RAIT set will give you 4 times the capacity, 4 times the throughput (with sufficient bus bandwidth), and the square of the failure rate.

This means you can back up partitions as large as four times your tape size with AMANDA, with higher reliability and speed.

Using a RAIT

If you have several tape devices on your system [currently either 3 or 5 drive sets are supported] you tell AMANDA to use them as a RAIT by listing them as a single tape device using /bin/csh curly-brace-and-comma notation, as in:

tapedev = "rait:/dev/rmt/tps0d{4,5,6}n"

which means that /dev/rmt/tps0d4n, /dev/rmt/tps0d5n, and /dev/rmt/tps0d6n are to be treated as a RAIT set. You can now mount three tapes, and label them with amlabel, etc.

Also, you want to create a new tape-type entry, which lists an n-drive RAIT set, for this RAIT-set. So if you were using an entry like:

define tapetype EXB-8500 {
       comment "Exabyte EXB-8500 drive on decent machine"
       length 4200 mbytes
       filemark 48 kbytes
       speed 474 kbytes
}

You would want to make a new one like:

define tapetype EXB-8500x3 {
       comment "Exabyte EXB-8500 3 drive stripe on decent machine"
       length 8400 mbytes
       filemark 200 kbytes
       speed 948 kbytes
}

and change your tapetype entry to: tapetype EXB-8500x3 to tell AMANDA about the multiple drive set.

Disaster Recovery

To assist in disaster recovery (as well as changer scripts) the AMANDA package now also includes amdd, which is a simple dd(1) replacement which supports (only) the "if=xxx", "of=xxx", "bs=nnn[kMb]" "skip=nnn" and "count=nnn" options, but which can read and write RAIT tapesets.

Using amdd and your usual AMANDA unpack instructions will suffice for disaster recovery from RAIT tape-sets.

File driver/Disk backups

Stefan G. Weichinger, November - December, 2003 ; minor updates in April, 2005.

Introduction

Since release 2.4.3 AMANDA supports the usage of a output driver called "file". See man amanda, section OUTPUT DRIVERS, for more information on its implementation. As the name suggests, this driver uses files as virtual (or file) tapes. Once created and labeled, these file tapes can be selected and changed with the standard tape-changer-interface of the AMANDA server.

Possible Uses

• Test installations: You can easily explore the rich features of AMANDA on systems without tape drives.
• Inexpensive installations: Without buying a tape drive you can enjoy the benefits of AMANDA and backup to a bunch of harddisks. You can create CD/DVD-sized backups which you can burn onto optical disks later.
• disk-based installations: You can use the file-driver to backup onto a set of file tapes hosted on a bunch of hard-disks or a RAID-system. Combined with another AMANDA-configuration that dumps the file tapes to real tapes, you can provide reliable backup with faster tapeless recovery. This is called "disk-to-disk-to-tape"-backup by some people today.

Setup

This guide assumes you have setup the basic AMANDA-services as described in Amanda Installation Notes

The configuration in this HOWTO is called "daily". The file tapes are also called vtapes in this document, which stands for "virtual tapes".

Please be sure to understand the differences between holding disks and file tapes. The two serve different purposes; holding disks allow for parallelism of multiple DLE's being backed up while file tapes are a replacement for physical tapes.

Before beginning you will need to decide on (a) dedicated part(s) of your hard disk(s) for your file tape storage. While this space could be spread among several file systems and hard disks, I recommend to dedicate at least a specific partition, better a specific physical harddisk to the task of keeping your vtapes. The use of a dedicated disk will speed things up definitely.

The disk space you dedicate for your vtapes should NOT be backed up by AMANDA. Also, for performance reasons there should be NO holding disks on the same partition as the vtapes, preferably not even on the same physical drive.

If you only have one harddisk, it will work out, too, but you will suffer low performance due to massive head-moving in your harddisk, resulting from copying data between the filesystems.

• Prepare the filesystem(s) used for the tapes. Decide on where to put your files, create the appropriate partition(s) and

filesystem(s) and mount them. In our example we have the dedicated partition hdc1, mounted on /amandatapes for vtape storage.

$ mount
[...]
/dev/hdc1 on /amandatapes type reiserfs (rw)
[...] 

Make sure there is space left. Determine the amount of space you will use.

$ df -h /amandatapes
Filesystem      Size  Used  Avail  Use%   Mounted on
/dev/hdc1        20G    0G    20G    0%   /amandatapes 

In our example we have 20GB diskspace left on /amandatapes.

• Determine length and number of tapes. After deciding on the number of vtapes you want to create, evenly allocate the

available space among them.

Look at the following rule of thumb: As many filesystems exhibit dramatically reduced performance when they are nearly full I have chosen to allocate only 90% of the available space. So we have:

     (Available Space * 0.9) >= tapelength * tapecycle

This is a very conservative approach to make sure you don´t suffer any performance drop due to a nearly-full-filesystem. As it is uncommon for AMANDA to fill, or almost fill an entire tape you may also wish to use more space than that. So you could determine possible combinations of tapelength/tapecycle with the more general formula:

     Available Space >= tapelength * tapecycle

In our example we take the conservative approach:

• 20 GB * 0.9 = 18 GB to use

and so we could create the following combinations:

• 18 GB = 18 GB * 1
• 18 GB = 9 GB * 2
• 18 GB = 6 GB * 3
• 18 GB = 3 GB * 6
• 18 GB = ......... you get the picture.

Using only one tape is generally considered a bad idea when it comes to backup, so we should use at least 3 tapes (for testing purposes), better 6 or more tapes.

• 18 GB = 3 GB * 6

so we get the value 3 GB for the tapelength if we want to use 6 tapes.

• Create a tapetype definition. Add a new tapetype definition similar to the following to your amanda.conf. I named my definition "HARD-DISK". Choose whatever name you consider appropriate.

define tapetype HARD-DISK {
      comment "Dump onto hard disk"
      length 3072 mbytes 	# specified in mbytes to get the exact size of 3GB
} 

You don´t have to specify the parameter speed (as it is commonly listed in tapetype definitions and reported by the program amtapetype). AMANDA does not use this parameter right now.

There is also an optional parameter filemark, which indicates the amount of space "wasted" after each tape-listitem. Leave it blank and AMANDA uses the default of 1KB.

• Think about tapechangers.

As you will use a set of vtapes, you have to also use a kind of vtape-changer. There are several tape-changer-scripts included in the AMANDA. Read more about tape-changer-scripts in AMANDA Tape Changer Support. Right now there are two scripts that can be used with vtapes. These scripts take different approaches to the handling of tapes.

• The script chg-multi handles many drives with a tape in each drive.
• The script chg-disk handles a library with one drive and multiple tapes.

So with vtapes you could look at it this way: chg-multi simulates multiple tape drives with one tape in each drive. chg-disk simulates one tape-library with multiple tapes in. As chg-multi exists for a much longer time than chg-disk, it is still used in many AMANDA-vtape-installations.

Contrary to chg-multi, which is a generic changer-script that must be somewhat adjusted to the use of the file-driver, chg-disk offers exactly the behavior needed for handling vtapes. IMHO the approach is much more logical, so I recommend to use chg-disk in new AMANDA-vtape-installations.

     To use chg-disk you need to have at least amanda-2.4.4p1-20031202.

Choose the one that fits your way of vtape-handling and -maintenance. In this HOWTO I only cover the use of chg-disk. Usage of chg-multi is pretty similar and will maybe covered in a later version of this document.

• Set up your tape-config. In the general section of amanda.conf, you have to set the parameters tapecycle , tapetype , tpchanger , changerfile , tapedev , rawtapedev and changerdev.

$ vi /usr/local/etc/amanda/daily/amanda.conf
...

tapecycle 6
tapetype HARD-DISK
tpchanger "chg-disk"
changerfile "/usr/local/etc/amanda/daily/changer"
tapedev  "file:/amandatapes/daily" 

This reflects the use of your defined tapetype. The parameter tapecycle tells AMANDA how much tapes can be used, Set this value according to the number of tapes you want to use. The parameter tapetype , points to the tapetype definition you have created before. The parameter tpchanger tells AMANDA to use the generic tape-changer-script to handle the vtapes. You can think of it as a virtual tape-changer-device.

The parameter changerfile is used to give chg-disk the "prefix" for the "%s-changer, %s-clean, %s-slot" files it needs. Use something like "changer" in your config-dir. Please note that this file does NOT have to exist, but it won't hurt anyway. The parameter tapedev tells the chg-disk-script where the root-dir for your vtapes is.

In our example the vtape-files go to /amandatapes. To separate multiple configurations, we decided to use subdirectories according to the configuration name "daily".

     The parameter changerdev is NOT needed with chg-disk as it is not parsed by chg-disk.

• Create the virtual tapes.

     Gene Heskett has committed a shell-script which creates and labels the vtapes in one step. Stefan G. Weichinger will 
     generalize this script and contribute it, this script will just read your settings in amanda.conf and create the 
     appropriate vtape-directories.

Now you have to create the tape-directories. chg-disk needs a directory structure like:

slot_root_dir -|
               |- info
               |- data -> slot1/
               |- slot1/
               |- slot2/
               |- ...
               |- slotn/ 
where 'slot_root_dir' is the tapedev 'file:xxx' parameter and 'n' is the tapecycle parameter.

So in our example we do:

$ mkdir /amandatapes/daily 
for the 'slot_root_dir' and
   $ mkdir /amandatapes/daily/slot1
   $ mkdir /amandatapes/daily/slot2
     ....  

for the virtual slots that will later contain the vtapes. If you have many vtapes to create and their names follow a pattern you may be able to do them all with a single loop such as:

$ for n in 1 2 3 4 5 6 7 8 9 10 11 12
> do
>    mkdir /amandatapes/daily/slot${n}
> done 

Create the info-file:

$ touch /amandatapes/daily/info

and link the first slot to the data-file (to "load" the vtape into the first slot):

$ ln -s /amandatapes/daily/slot1 /amandatapes/daily/data 

Make sure the AMANDA-user has write-permissions on these directories:

$ chown -R amanda_user /amandatapes
$ chgrp -R amanda_group /amandatapes
$ chmod -R 750 /amandatapes 

• Label the virtual tapes. As the virtual tapes are handled just like physical tapes by the AMANDA-Server they have to be

labeled before use.

$ amlabel daily daily1 slot 1
 ....
$ amlabel daily daily2 slot 2
 ....  

If you have many vtapes to label and their names follow a pattern you may be able to do them all with a single loop such as:

$ for n in 1 2 3 4 5 6 7 8 9 10 11 12
> do
>    amlabel daily daily${n} slot ${n}
> done 

Label all your created tapes according to the "labelstr"-parameter in your amanda.conf. Consult the amlabel-man-page for details.

• Test your setup with amcheck. Run amcheck daily (or, more general, amcheck <config>) and look for anything AMANDA complains about.

A proper output looks like:

$ amcheck daily
Amanda Tape Server Host Check
--
Holding disk /amhold: 6924940 KB disk space available,
that's plenty
amcheck-server: slot 2: date 20031115 label daily02
(exact label match)
NOTE: skipping tape-writable test
Tape daily02 label ok
Server check took 0.377 seconds 

Recheck your files if errors occur.

Recovery

Recovering files from vtapes is very similar to recovering files from a "real" tapechanger. Make sure you read the chapter Restore. I will simply paste a amrecover-session here (provided by JC Simonetti, author of chg-disk):

# /usr/local/amanda/sbin/amrecover woo
AMRECOVER Version 2.4.4p3. Contacting server on backupserver.local ... 
220 backupserver AMANDA index server (2.4.4p3) ready.
200 Access OK
Setting restore date to today (2004-10-08)
200 Working date set to 2004-10-08.
Scanning /BACKUP2/holding...
Scanning /BACKUP/holding...
200 Config set to woo.
200 Dump host set to backupserver.local.
Trying disk /tmp ...
$CWD '/tmp/RECOVER' is on disk '/tmp' mounted at '/tmp'.
200 Disk set to /tmp.
Invalid directory - /tmp/RECOVER
amrecover> sethost backupserver.local
200 Dump host set to backupserver.local.
amrecover> setdisk /
200 Disk set to /.
amrecover> cd /etc
/etc
amrecover> add passwd
Added /etc/passwd
amrecover> list
TAPE B3_14 LEVEL 0 DATE 2004-09-26
       /etc/passwd
amrecover> extract

Extracting files using tape drive file:/BACKUP2/slots/ on host
backupserver.local. The following tapes are needed: B3_14

Restoring files into directory /tmp/RECOVER
Continue [?/Y/n]? Y

Extracting files using tape drive file:/BACKUP2/slots/ on host
backupserver.local. Load tape B3_14 now
Continue [?/Y/n/s/t]? Y
. /etc/passwd
amrecover> quit
200 Good bye.  

Nothing spectacular? The trick is this: When AMANDA asks you

Load tape B3_14 now 
Continue [?/Y/n/s/t]?  

you have to run the following in a second terminal:

$ amtape woo slot 14
amtape: changed to slot 14 on file:/BACKUP2/slots/ 

This step is necessary to load the proper tape into your virtual changer. Let me express this in a more general way:

When amrecover prompts for the tape it needs to restore the files you requested, you have to "load" the tape it requests. The recommended way to do this is to use amtape. The options that make sense in this context are:

# amtape
Usage: amtape <conf> <command>
       Valid commands are:
               [...]
               slot <slot #>        load tape from slot <slot #>
               [...]
               label <label>        find and load labeled tape
               [...] 

If you know which slot contains the requested tape (for example, if you have tape daily01 in slot 1, tape daily02 in slot 2, and so on) you may use the first option. If you just know the label of the tape you need, use the second option.

To continue the upper example:

amtape woo slot 14 	        # option 1 OR
amtape woo label B3_14 	# option 2 

amtape will return something like:

amtape: label B3_14 is now loaded.  

After this you can return to your amrecover-session and continue restoring your files.

Please be aware of the fact reported by JC Simonetti: " I have never never used the "settape" command of amrecover [with chg-disk] since there's some problems with it (tape not loaded correctly, or impossible to change from tape to tape when restoring data shared accross multiple tapes...) "

!!NEW!!

Since Amanda 2.4.3 you can let amrecover use the complete changer instead of the currently loaded tape too. No need to open a second window to load the correct tape.

For this add in amanda.conf:

amrecover_do_fsf  yes
amrecover_check_label  yes
amrecover_changer  "changer"

With the last line we give the changer a name, which we can use instead of the tape device in amrecover, when starting the command:

# /usr/local/amanda/sbin/amrecover woo -d changer

or from inside with the settape command or even:

Extracting files using tape drive file:/BACKUP2/slots/ on host
backupserver.local. Load tape B3_14 now
Continue [?/Y/n/s/t]? t
New tape device [?]: changer
Using tape "changer" from server backupserver.local.
Continue [?/Y/n/s/t]? y

Server-side and Client-side encryption

• a new dumptype option, encrypt is added.
• specify either client or server side in the dumptype (not both):
  • encrypt client or encrypt server
• specify client side encryption program:
  • client_encrypt "your encryption program"
    • a sample encryption/decryption program amcrypt is provided. amcrypt is a wrapper of aespipe.
    • espipe supports AES128, AES192 and AES256 and it uses SHA-256, SHA-384 and SHA-512 respectively.
    • any encryption/decryption program can be used as long as it reads from stdin and writes to stdout.
  • client_decrypt_option "decrypt parameter" #default to -d
• specify server side encryption program:
  • server_encrypt "your encryption program"
    • can use amcrypt as in client encryption.
  • server_decrypt_option "decrypt parameter" #default to -d

• The logic assumes compression then encryption during backup(thus decrypt then uncompress during restore). Specifying client-encryption and server-compression is not supported

• dumptype sample:

define dumptype custom-tar {
      global
      program "GNUTAR"
      comment "root partitions dumped with encryption"
      compress client fast
      encrypt  server
      server_encrypt "/usr/local/sbin/amcrypt"
      server_decrypt_option "-d"
      index
      priority low 
}

• The code is partially based on Matthieu Lochegnies's custom compress patch and Stefan G. Weichinger's

amgtar script.

• Code has been commited to the sourceforge CVS, rpm can be downloaded from http://www.zmanda.com/downloads.html

Additional packages needed

• aespipe http://loop-aes.sourceforge.net/aespipe/aespipe-v2.3b.tar.bz2 and the bz2aespipe-wrapper that comes with it. It gets patched as described later.
• the wrapper-script amcrypt, as listed below,
• GNU-PG http://www.gnupg.org/(en)/download/index.html. This should be part of most current operating systems already.

Setup

• Configure and compile aespipe:

tar -xjf aespipe-v2.3b.tar.bz2
cd aespipe-v2.3b
./configure
make
make install

• Generate and store the gpg-key for the AMANDA-user:

# taken from the aespipe-README
head -c 2925 /dev/random | uuencode -m - | head -n 66 | tail -n 65 | \
gpg --symmetric -a > ~amanda/.gnupg/am_key.gpg

• This will ask for a passphrase. Remember this passphrase as you will need it in the next step.

Store the passphrase inside the home-directory of the AMANDA-user and protect it with proper permissions:

echo my_secret_passphrase > ~amanda/.am_passphrase
chown amanda:disk ~amanda/.am_passphrase
chmod 700 ~amanda/.am_passphrase

• We need this file because we don't want to have to enter the passphrase manually everytime we run amdump. We have to patch bz2aespipe to read the passphrase from a file. I have called that file ~amanda/.am_passphrase.

• Store the key and the passphrase in some other place as well, without these information you can't access any tapes that have been encrypted with it (this is exactly why we are doing all this, isn't it? ;) ).

• create amcrypt(or it will available in sourceforge and the rpms) as below:

#!/bin/sh
#
# Original wrapper by Paul Bijnens
#
# worked by Stefan G. Weichinger
# to enable gpg-encrypted dumps via aespipe
# also worked by Matthieu Lochegnies for server-side encryption
prefix=/usr/local
exec_prefix=${prefix}
sbindir=${exec_prefix}/sbin
AMANDA_HOME=~amanda
AM_AESPIPE=${exec_prefix}/sbin/amaespipe
AM_PASSPHRASE=$AMANDA_HOME/.am_passphrase

$AM_AESPIPE "$@" 3< $AM_PASSPHRASE
rc=$?
exit $rc

• create amaespipe(or it will available in sourceforge and the rpms) which is based on wrapper-script bz2aespipe, which comes with the aespipe-tarball:

#! /bin/sh

# FILE FORMAT
# 10 bytes: constant string 'bz2aespipe'
# 10 bytes: itercountk digits
# 1 byte: '0' = AES128, '1' = AES192, '2' = AES256
# 1 byte: '0' = SHA256, '1' = SHA384, '2' = SHA512, '3' = RMD160
# 24 bytes: random seed string
# remaining bytes are bzip2 compressed and aespipe encrypted
# These definitions are only used when encrypting.
# Decryption will autodetect these definitions from archive.
ENCRYPTION=AES256
HASHFUNC=SHA256
ITERCOUNTK=100
AMANDA_HOME=~amanda
WAITSECONDS=1
GPGKEY=""$AMANDA_HOME/.gnupg/am_key.gpg"
FDNUMBER=3
PATH=/usr/bin:/usr/local/bin
export PATH

if test x$1 = x-d ; then
   # decrypt
   n=`head -c 10 - | tr -d -c 0-9a-zA-Z`
   if test x${n} != xbz2aespipe ; then
       echo "bz2aespipe: wrong magic - aborted" >/dev/tty
       exit 1
   fi
   itercountk=`head -c 10 - | tr -d -c 0-9`
   if test x${itercountk} = x ; then itercountk=0; fi
   n=`head -c 1 - | tr -d -c 0-9`
   encryption=AES128
   if test x${n} = x1 ; then encryption=AES192; fi
   if test x${n} = x2 ; then encryption=AES256; fi
   n=`head -c 1 - | tr -d -c 0-9`
   hashfunc=SHA256
   if test x${n} = x1 ; then hashfunc=SHA384; fi
   if test x${n} = x2 ; then hashfunc=SHA512; fi
   if test x${n} = x3 ; then hashfunc=RMD160; fi
   seedstr=`head -c 24 - | tr -d -c 0-9a-zA-Z+/`
   aespipe -K ${GPGKEY} -p ${FDNUMBER} -e ${encryption} -H ${hashfunc} -S ${seedstr} -C ${itercountk} -d 
else
   # encrypt
   echo -n bz2aespipe
   echo ${ITERCOUNTK} | awk '{printf "%10u", $1;}'
   n=`echo ${ENCRYPTION} | tr -d -c 0-9`
   aesstr=0
   if test x${n} = x192 ; then aesstr=1; fi
   if test x${n} = x256 ; then aesstr=2; fi
   n=`echo ${HASHFUNC} | tr -d -c 0-9`
   hashstr=0
   if test x${n} = x384 ; then hashstr=1; fi
   if test x${n} = x512 ; then hashstr=2; fi
   if test x${n} = x160 ; then hashstr=3; fi
   seedstr=`head -c 18 /dev/urandom | uuencode -m - | head -n 2 | tail -n 1`
   echo -n ${aesstr}${hashstr}${seedstr}
   aespipe -K ${GPGKEY} -p ${FDNUMBER} -e ${ENCRYPTION} -H ${HASHFUNC} -S ${seedstr} -C ${ITERCOUNTK} -w ${WAITSECONDS}
fi
exit 0

Changes from bz2aespipe:

• Decreased WAITSECONDS: No need to wait for 10 seconds to read the passphrase.
• Removed bzip2 from the pipes: AMANDA triggers GNU-zip-compression by itself, no need to do this twice (slows down things, blows up size).
• Added options -K and -p: This enables aespipe to use the generated gpg-key and tells it the number of the file-descriptor to read the passphrase from.

You may set various parameters inside bz2aespipe. You may also call bz2aespipe with various command-line-parameter to choose the encryption-algorithm, hash-function etc. . For a start I have chosen to call bz2aespipe without command-line-options.

Plans

There are several TODO:

• test to see if aespipe can be replaced by gpg.
• test to see if public-key encryption works.

Custom Compression

• compress client custom
  • Specify client_custom_compress "PROG"
  • PROG must not contain white space and it must accept -d for uncompress.

• compress server custom
  • Specify server_custom_compress "PROG"
  • PROG must not contain white space and it must accept -d for uncompress.

• sample dumptype:

 define dumptype custom-tar {
 global
 program "GNUTAR"
 comment "root partitions dumped with custom compression"
 compress server custom
 server_custom_compress "/usr/bin/my_gzip"
 priority low
}

• I have tested custom compression using bzip2. Dumps works fine. Amrestore has a glitch on which

the image gets uncompressed correctly and written to a temp file but gets a broken-pipe error. I am investigating the problem.