Backups with AMANDA
Background
We have two main file-servers (musashi, and yamato), which each perform their own backups Monday through Friday (typically). Musashi has a SCSI-attached HP LTO-1 Ultrium 230 (Aug. 2003) tape-drive; yamato has a replacement Ultrium 232 (Nov. 2006) tape-drive.
Yamato only backs up it's SCSI-connected RAID drives. Musashi doesn't back up one of it's own SCSI-connected RAID drives (too much non-essential data), but musashi does "reach out" and backup other machines' files. What gets backed up is listed/controlled in the /etc/amanda/Dailyxxx/disklist. Both yamato and musashi have amanda configured as a server and client, while the remote machines captured by musashi have amanda configured as a client-only.
Amanda Server Configuration
The first step was to determine the tapetype entry, in /etc/amanda/Dailyxxx/amanda.conf; here are the results from two different tests on separate systems:
Ultrium 230
define tapetype Ultrium230 {
comment "HP Ultrium 230, produced by amtapetype"
length 101376 mbytes
filemark 0 kbytes
speed 13871 kps
}
Ultrium 232
amanda@trainwreck ~ $ amtapetype -f /dev/nst0 -e 100G -o
Writing 1024 Mbyte compresseable data: 37 sec
Writing 1024 Mbyte uncompresseable data: 72 sec
WARNING: Tape drive has hardware compression enabled
Estimated time to write 2 * 102400 Mbyte: 14400 sec = 4 h 0 min
wrote 3080192 32Kb blocks in 94 files in 7025 seconds (short write)
wrote 3096576 32Kb blocks in 189 files in 7511 seconds (short write)
define tapetype unknown-tapetype {
comment "just produced by tapetype prog (hardware compression on)"
length 96512 mbytes
filemark 0 kbytes
speed 13611 kps
}
Tape Drive Compression
Compression can be turned on or off using the mt tool noted below, then initiating the tapetype check; kill the tapetype check with ctrl-C when you've got enough info (takes quite a few minutes)
trainwreck ~ # mt -f /dev/nst0 defcompression 1 trainwreck ~ # su - amanda amanda@trainwreck ~ $ amtapetype -f /dev/nst0 -e 100G -o Writing 1024 Mbyte compresseable data: 42 sec Writing 1024 Mbyte uncompresseable data: 72 sec WARNING: Tape drive has hardware compression enabled Estimated time to write 2 * 102400 Mbyte: 14400 sec = 4 h 0 min amanda@trainwreck ~ $ logout trainwreck ~ # mt -f /dev/nst0 defcompression 0 trainwreck ~ # su - amanda amanda@trainwreck ~ $ amtapetype -f /dev/nst0 -e 100G -o Writing 512 Mbyte compresseable data: 38 sec Writing 512 Mbyte uncompresseable data: 39 sec Estimated time to write 2 * 102400 Mbyte: 15600 sec = 4 h 20 min
Amanda Client Configuration
Unfortunately, with the Gentoo packaging, you get more than you need, for just a client:
inferno / # emerge -pv amanda These are the packages that would be merged, in order: Calculating dependencies... done! [ebuild N ] sys-block/mtx-1.2.18 164 kB [ebuild N ] sci-visualization/gnuplot-4.0-r1 USE="emacs gd png readline -X -doc -ggi -pdf -plotutils (-svga) -xemacs" 2,111 kB [ebuild N ] app-arch/mt-st-0.7-r1 35 kB [ebuild N ] sys-apps/xinetd-2.3.14 USE="perl tcpd" 295 kB [ebuild N ] app-arch/dump-0.4.41 USE="readline -ermt -static" 277 kB [ebuild N ] app-backup/amanda-2.4.5 USE="-berkdb -debug -gdbm -samba -xfs" 1,506 kB Total: 6 packages (6 new), Size of downloads: 4,386 kB
There are a couple of separate steps required, for amanda-client to work - configuring the xinetd meta-server, and configuring amanda. Most aggravations seem to stem from permissions, whether it's the server-access through xinetd, or the amanda-permitted-user in .amandahosts.
inferno / # emacs -nw /etc/xinetd.d/amanda
service amanda
{
socket_type = dgram
protocol = udp
wait = yes
user = amanda
group = amanda
groups = yes
server = /usr/libexec/amandad
# You need to ensure this points to your Amanda server!
# Don't just remove it!
only_from = trainwreck (clearly, this should point to your server)
disable = no
}