How To:Run Amanda Server on Cygwin

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Contents

Install Cygwin

The following Cygwin packages are required for binary installation (may be incomplete):

  • Category BASE: standard
  • Category MISC: gzip
  • Category MISC: tar
  • Category NET: inetutils

You need also these packages to build from source (may be incomplete):

  • Category DEVELOP: ALL
  • Category INTERPRETERS: m4, gawk ?
  • Category LIBS:default selection? (libc, libiconv, others?)

One user reported some problems with access rights when running under Cygwin, which he solved by setting the CYGWIN environment variable to nontsec. I do not believe this is necessary if you run the AMANDA daemon as System (see below).

Other Preparation

When doing backups on a NT, Windows 2000 or Windows XP system, the choice of user and group will be important if you are to properly interact with the security mechanisms of these more modern Microsoft product. For Windows 95/98/ ME this is probably a non-issue. The most privileged account on the Windows systems is 'System', and I have chosen to use this account for Amanda backups to ensure that I can access the widest set of files. On Unix we would run as root, with equivalent access permissions. I have also chose to run under the 'Administrators' group, another standard Windows group. Ensure these exist before you continue - or identify another account to use. The Cygwin installation postinstall script should have already populated /etc/passwd and etc/group with these entries.

  • Make sure that System (or SYSTEM) has a home directory specified in /etc/passwd.

I used _/home/root_. You'll need to put the file .amandahosts here later. The relevant lines from my file /etc/passwd are:

SYSTEM:*:18:18:,S-1-5-18:/home/root:
root:*:18:18:,S-1-5-18:/home/root:

EDIT: You should not run the service as System, as that opens a security hole. The best thing to do would be to create a new user account and add them to the Backup Operators group on each client machine. That way the account can still backup files, but not pose a security risk. If connected to an AD, simply create the user and add them to the domain Backup Operator group and add that group to the local group on the machines. Once I've tested this method, I'll provide exact procedures

Compile Amanda

After installing Cygwin, unpack the Amanda sources, typically in /usr/src/amanda or something similar. In the amanda directory, you will need to execute:

automake  # this may not be necessary in the official release
autoconf  # this may not be necessary in the official release

./configure --without-server \
 --without-force-uid \
 --with-user=<amanda backup user> \
 --with-group=Administrators
make
make       # yes, I needed to run it a second time
make install

The use of your own login instead of SYSTEM requires some explanation. If you were to call runconfigure with SYSTEM instead of your own login id as part of the -with-user parameter, the installation process will fail due to the way Cygwin and the NT/W2K/XP security system interact. Once you chown a file to another user (like SYSTEM) you are no longer able to chgrp or chmod the file. The installation process will abort at this point. By installing the files owned by yourself, you will be able to chgrp and chmod them as expected. Note that you still RUN as SYSTEM from /etc/inetd.conf (see below).

Configure Cygwin files

You have to modify some config files:

  • /etc/inetd.conf: cleanup un-needed entries: Comment out any entries you do not need by placing a '#' at the start of the lines. This is just good practice, and if any of the entries reference non- existent users (e.g. uucp) inetd may not start up.
  • To /etc/inetd.conf: add
          amanda dgram udp wait System /usr/local/libexec/amandad amandad

ATTENTION: Use tabs, don't use spaces.

The files created in the followng steps - .amandahosts, gnutar-lists, amandates should be owned by the user System - same user as inetd.conf
  • Create _/home/root/.amandahosts_ (or whereever System's home directory is): <amanda server> <amanda user>
  • Create the following amanda directories and the file amandates:
    mkdir -p /usr/local/var/amanda/gnutar-lists
    mkdir /tmp/amanda
    touch /etc/amandates 

Configure Windows System Files

Update the Windows services list. To WINDIR\Services: add

          amanda 	10080/udp	# Amanda backup services
          amandaidx 	10082/tcp	# Amanda backup services
          amidxtape 	10083/tcp	# Amanda backup services

where WINDIR is C:\WINNT\system32\drivers\etc or something similar. The last two lines are needed if you want to use amrecover.

Ensure that the default Windows PATH environment variable include your Cygwin / bin directory. This is necessary since inetd and hence the amandad that it spawns will not have the advantage of being started by the standard bash shell startup script and won't find the needed dynamic libraries (e.g. cygwin1.dll). My PATH is:

_%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;C:\cygwin\bin_

This is on XP; My Computer, right click Properties, click on Environment Variables (at the bottom). Yours may vary, but make sure the Cygwin bin directory is represented somewhere in the PATH.

Configure inetd to run automatically as a service

If you want to test your installation, you can call inetd from bash prompt:

/usr/sbin/inetd -d

Windows 98/ME

  • To start after the user logs in: Create a shortcut to c:\cygwin\usr\sbin\inetd.exe in WINDIR\start menu\programs\startup
  • To start before the user logs in: Add the string key
CygwinInetd=C:\cygwin\usr\sbin\inetd.exe   
under  HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices

in the registry. You'll see a dos-like window on the startup: I did not find a solution to iconize or to make invisible (suggestions are welcome).

Windows NT/2000/XP

From bash prompt, type:

/usr/sbin/inetd --install-as-service

Then, to start/stop the inetd service use the Services control panel or the following Windows command: net start/stop inetd

Notes on Amanda backup options

Compression

Currently, client side compression does not work, probably due to problems in pipe emulation in Cygwin. I have not tried to debug this yet. This may be addressed in a subsequent release, or it could be fixed in later releases of Cygwin. Due to this issue, we recommend that if you want compressed dumps from Windows clients, you configure Amanda for server compression in amanda.conf on your Amanda server:

define dumptype srv-comp-tar {
   global
   comment "partitions dumped via tar with server compression"
   program "GNUTAR"
   compress server fast
   exclude list ".amanda.exclude"
}

Exclude Lists

A note on exclude lists is also in order. If you specify a relative path, it will be expected that the file is in or relative to the root of the directory you are planning to dump. Typically this will not be '/' but '/cygdrive/c' or something similar if you want to get the Windows files and the Cygwin files. '/' is taken to be the root of the Cygwin tree, normally something like C: \cygwin or possibly C:\Program Files\cygwin.

Debugging Files

Amanda will leave debugging files in /tmp/amanda if it exists. I have recommended to create this directory above

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