On Thu, 21 Mar 2002 at 12:50pm, Mark Schoonover wrote
> Thanks for the quick replies! I have found the error of my ways,
> which leads me to a few more questions! The way I understand it is a 'dump'
> is one cron job of amdump running. OK no problem there. Now, how do I
> estimate how many filesystems I can backup to a single tape?? Trial and
> error?? Not sure what a level 0 is offhand. The best I can figure out on my
> own is an entire dump of all filesystems in one run. Josh, can I bother you
> for a copy of your tapetype??
A level 0 is a full dump of a filesystem. For example:
[jlb@chaos jlb]$ df
Filesystem 1k-blocks Used Available Use% Mounted on
/dev/sda1 248895 95924 140121 41% /
.
.
.
If I had a disklist entry "chaos / $DUMPTYPE", then a level 0 would take
up ~95MB. A level 1 (i.e. an incremental) the next day would only backup
what had changed between the time the level 1 was run and the time of the
last level 0.
So, to estimate how many level 0s will fit on a tape, just use df (or du)
to find the size of your disklist entries and add them up. Also,
remember that, after a while, amanda will balance full backups throughout
the dumpcycle (filling the rest of the tape with incrementals). This is
what allows you to backup an amount of data larger than your tapes.
Here's my tapetype for an Eliant 820 using XL tapes:
define tapetype Eliant-820 {
comment "just produced by tapetype program"
length 6680 mbytes
filemark 0 kbytes
speed 949 kps
}
--
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University
