Results missing

Amcheck passes all tests?

First test with amcheck and solve all issues it complains about. (Messages marked with "NOTE" do not need to be handled.)

Timeout during estimate?

If the estimates take too long, the Amanda server may have already given up waiting for that client. Find out how long the estimate took on the client. Locate the debug file for sendsize on that client in the AMANDA_DBGDIR directory. The last line of the file contains a timestamp. Also count how many disklist entries (DLE) there are for this host.

$ tail -1 sendsize.20051206000412.debug
 sendsize: time 256.797: pid 16014 finish time Tue Dec  6 00:08:29 2005

$ grep 'estimate time'  sendsize.20051206000412.debug
sendsize[16017]: estimate time for /space level 0: 0.653
sendsize[16017]: estimate time for /space level 1: 0.007
sendsize[16016]: estimate time for / level 0: 217.741
sendsize[16016]: estimate time for / level 1: 25.902
sendsize[16038]: estimate time for /boot level 0: 0.044
sendsize[16038]: estimate time for /boot level 1: 0.007
sendsize[16041]: estimate time for /var level 0: 11.492
sendsize[16041]: estimate time for /var level 2: 1.037

The Amanda server waits etimeout seconds (default 300 s) muliplied by the number of disklist entries for that host. In the above example that would be 4 * 300 seconds. (The above estimate took 257 seconds, so that is good.)

You may need to adjust the etimeout value in amanda.conf. Take into account that Amanda can ask estimates for 3 dump levels (level 0, level N, and level N+1) for each disklist entry.

Investigate why some of the estimates take so long. Using gnutar on a filesystem with many small files can take a very long time. On the other hand, a non-responsive NFS-server may block gnutar for a long time, when it traverses the tree and does a stat() on that mountpoint (it is only after the stat() that gnutar can know it would cross a filesystem).

Since Amanda version 2.4.5 you can also use faster but less accurate methods for the estimates with a parameter for the dumptype (see amanda.conf):

estimate client|calcsize|server

client

Use the same program as the dumping program, this is the most accurate way to do estimates, but it can take a long time. This is the default.

calcsize

Use a faster program to do estimates, but the result is less accurate.

server

Use only statistics from the previous run to give an estimate, it takes only a few seconds but the result is not accurate if your disk usage changes from day to day.

Choose a faster method for a particular large and slow partition, e.g.:

disklist:

 myhost.example.com   /cvsrep  {
         comp-user-tar
         estimate calcsize
       }

Timeout due to firewall?

If there is a firewall between (or on!) the client and server, the reply UDP packet may be dropped by the firewall. Some firewalls time out UDP replies on 40 seconds already!

When using the iptables ip_conntrack_amanda kernel module in the firewall, you may need to adjust the master_timeout parameter for this module. The master_timeout is the time that the module keeps connections tracked on the 10080/udp port.

/etc/modprobe.conf:

options  ip_conntrack_amanda  master_timeout=3600

A manual test for UDP timeouts can be simulated with the netcat utility. On the Amanda client first make sure nothing is already listening on port 10080 (modify (x)inetd.conf ). Then start on the Amanda client:

 $ nc -vv -u -l -p 10080

Next on the Amanda server:

 $ nc -vv -u theclient.example.com 10080

What you type on one side should appear on the other. The firewall is probably configured to pass replies through only when initiated from the server: first type something on the server, then on the client. Let the connection idle for some longer time, and type something again on the client, and verify if the server receives the bytes.

UDP packet too large?

One of the possible reasons is that you have requested too many disklist entries for a single host. Because Amanda sends the estimate request in a single UDP packet, it is possible for the estimate request or reply to exceed the maximum packet size. Fixing this problem is suprisingly difficult. This issue can come up even if things were working initially, because the number of estimates taken increases as full and level-1 dumps are done.

The best and simplist way to address this problem is to switch to using SSH authentication, which does not have this issue.

By default, Amanda sends packets of no more than 32 KB. If your system supports it, you can increase this to 64 KB by editing the source.

FreeBSD 5.1 (and later) and also Mac OS 10.4 and later limit the UDP packet size to 9216 bytes by default. That limit can be increased up to 64Kbytes with the command:

# sysctl net.inet.udp.maxdgram=63535

or automatically when rebooting by adding to the file /etc/sysctl.conf this line:

net.inet.udp.maxdgram=65535

Other OSes may use different commands to increase the maximum UDP packet size. You'll have to look in the man pages for that OS.

Sometimes buggy UDP implementations garble packages exceeding the MTU size (1500 bytes on ethernet).

You can see the UDP reply packet in the amandad.datetime.debug file in the AMANDA_DBG directory on the client:

...
amandad: time 0.000: got packet:
--------
Amanda 2.4 REQ HANDLE 003-B88F0708 SEQ 1133823863
SECURITY USER amanda
SERVICE sendsize
OPTIONS features=fffffeff9ffe7f;maxdumps=2;hostname=myclient.example.com;
GNUTAR /space 0 1970:1:1:0:0:0 1 OPTIONS |;bsd-auth;compress-fast;index;
GNUTAR /space 1 2005:11:26:0:46:56 1 OPTIONS |;bsd-auth;compress-fast;index;
GNUTAR /var 0 1970:1:1:0:0:0 1 OPTIONS |;bsd-auth;compress-fast;index;
GNUTAR /var 1 2005:12:3:0:41:14 1 OPTIONS |;bsd-auth;compress-fast;index;
GNUTAR /boot 0 1970:1:1:0:0:0 1 OPTIONS |;bsd-auth;compress-fast;index;
GNUTAR /boot 1 2005:11:29:2:11:9 1 OPTIONS |;bsd-auth;compress-fast;index;
GNUTAR / 0 1970:1:1:0:0:0 1 OPTIONS |;bsd-auth;compress-fast;index;
GNUTAR / 1 2005:12:1:0:27:38 1 OPTIONS |;bsd-auth;compress-fast;index;
GNUTAR / 2 2005:12:3:0:26:8 1 OPTIONS |;bsd-auth;compress-fast;index;
--------
...

The UDP packet is the text between the lines with hyphens. Copy/paste the text in a file, and count the characters with "wc". Add the 20 bytes for the IP-header plus 8 bytes for the UDP-header. This is the size of the UDP packet.

A network trace on traffic for port 10080/udp (with snoop on Solaris, tcpdump, ethereal...) may help investigating this further.

You can notice that amanda asks for 1, 2 or even 3 different dump levels of each disklist entry . A run on a different day, could result in more or less lines, bumping into the UDP packet size limit on some days only. (After a "amadmin config force myclient.example.com" would request a lot less estimates, making this it succeed maybe.)

If you use many include/exclude directives in the dumptypes, find out what takes less size bytes to communicate: a pathname on the client with "include list", or a few "include file append" directives in the dumptype itself.

One possible work-around is to try to shorten the pathnames of the directories, so that more requests fit in the UDP packet. You may create short-named links in some directory or exclude files closer to the root (/) so as to reduce the length of names. I.e., instead of backing up /usr/home/foo and /usr/home/bar, create the following links:

  /.foo -> /usr/home/foo
  /.bar -> /usr/home/bar

then list /.foo and /.bar in the disklist.

Another approach is to group sub-directories in backup sets, instead of backing up them all separately. For example, create /usr/home/.bkp1 and move `foo' and `bar' into it, then create links so that the original pathnames remain functional. Then, list /usr/home/.bkp1 in the disklist. You may create as many `.bkpN' directories as you need.

A simpler approach, that may work for you, is to backup only a subset of the subdirectories of a filesystem separately. The others can be backed up together with the root of the filesystem, using an exclude list that prevents duplicate backups.

---

Note: The other FOM-entries (wrapper-stuff) are yet to be discussed. See FOM

---

See more amdump issues.

[We are delicate. We do not delete your content.] [l_sp1]

ringtone maker verizon ringtone US Cellular Ringtone bcbg shoes waterford crystal swarovski crystal bead mesothelioma lawsuits mesothelioma symptoms mesothelioma diagnosis Sexy Prom Dresses Naturalizer Shoes Aero Bed Free Sprint Ringtones Free Verizon Ringtones free nextel ringtones sexy prom dress Formal Prom Dresses cheap prom dresses Plus Size Prom Dresses tiffany prom dresses erotic games strip poker pokemon trading card game rom hoyle card games teen bra Bra Teen Cleavage Micro Bikini Teens Bra sexy bras bulma bra sheer bra auto loan calculator Federal Student Loan Consolidation private student loan consolidation acs student loans countrywide home loans refinance home loan st louis wacoal bras teen bra unsecured signature loan Countrywide Home Loans Formal Prom Dresses Sexy Prom Dress cocktail dresses TMobile water softener tankless water heater oscar dresses mother of the bride dresses bridesmaid dresses cocktail dresses formal dresses easter dresses evening dresses evening gowns ball gowns formal gowns plus size wedding gowns rockport shoes reverse osmosis water filter merrell shoes casino royale throat pokers free strip poker crazy game of poker poker chips texas holdem poker game online poker aide online poker assistant casino directory gambling online online pai gow poker hooters casino atlantic city casinos buy ativan online buy oxycontin online buy alprazolam online buy alprazolam cialis no prescription xanax xr ultram er buy ultram online generic fioricet buy fioricet online phentermine 37 5mg bontril sr cheap bontril ambien cr buy didrex online adipex without a prescription buy tamiflu buy clonazepam purchase tramadol without a prescription buy acyclovir buy codeine private poker tournament freeroll poker tournament caribbean stud poker paradise poker play free strip poker erotic games strip poker online poker calculator online poker tracker buy diazepam didrex buy didrex adipex without prescription adipex p clonazepam buy clonazepam diethylpropion celexa paxil cr lorazepam hydrocodone apap lortab klonopin norco buy propecia order propecia phendimetrazine Butalbital cheap xenical wellbutrin xl valtrex vicodin without prescription las vegas casino coupons las vegas palms casino hooters casino las vegas microgaming casino bonus playtech casino bonus rtg casino bonus grand casino tunica grand casino mille lacs grand casino coushatta grand casino hinckley grand casino hinkley