But since amanda is a client/server setup, and the client can be told to do the compression, the next consideration would be the occupied network bandwidth while the backup is running. Using client compression can make night and day differences in the network loading and its general useability while the backup is in progress. You'll need at least 100baseT if its going to get well into the 10's of gigabytes per session.
The gain with the parallelisation of Amanda can be amazing! Here is a snippet of my archive run last weekend:
STATISTICS:
Total Full Daily
-------- -------- --------
Estimate Time (hrs:min) 0:13
Run Time (hrs:min) 8:12
Dump Time (hrs:min) 42:57 42:57 0:00
Output Size (meg) 70427.9 70427.9 0.0
Original Size (meg) 149337.0 149337.0 0.0
Avg Compressed Size (%) 47.2 47.2 --
Filesystems Dumped 114 114 0
Avg Dump Rate (k/s) 466.3 466.3 --
It means that it did a full backup in 8 hours 12 minutes, that would take almost 43 hours when run sequentially (what many simple backup scripts actually do!). We have a mix of fast and old slow machines (Sun Sparc IPX, Intel Pentium 150Mhz with 32 MByte RAM etc); also a mix of 100baseT and 10baseT network cards. Amanda does them all (do there still exist veritas clients for SunOS 4.1.4?).
For curiosity, here is my Daily config statistics section:
STATISTICS:
Total Full Daily
-------- -------- --------
Estimate Time (hrs:min) 0:28
Run Time (hrs:min) 2:52
Dump Time (hrs:min) 11:40 8:45 2:55
Output Size (meg) 16658.4 15116.6 1541.8
Original Size (meg) 42697.5 37183.0 5514.5
Avg Compressed Size (%) 39.0 40.7 28.0
Filesystems Dumped 116 22 94 (1:89 2:5)
Avg Dump Rate (k/s) 406.4 491.5 150.7-- Paul Bijnens, Xplanation Tel +32 16 397.511 Technologielaan 21 bus 2, B-3001 Leuven, BELGIUM Fax +32 16 397.512 http://www.xplanation.com/ email: [EMAIL PROTECTED] *********************************************************************** * I think I've got the hang of it now: exit, ^D, ^C, ^\, ^Z, ^Q, F6, * * quit, ZZ, :q, :q!, M-Z, ^X^C, logoff, logout, close, bye, /bye, * * stop, end, F3, ~., ^]c, +++ ATH, disconnect, halt, abort, hangup, * * PF4, F20, ^X^X, :D::D, KJOB, F14-f-e, F8-e, kill -1 $$, shutdown, * * kill -9 1, Alt-F4, Ctrl-Alt-Del, AltGr-NumLock, Stop-A, ... * * ... "Are you sure?" ... YES ... Phew ... I'm out * ***********************************************************************
