On Monday 16 December 2002 17:44, Sykora, Dale wrote:
>Hello,
> I am new to amanda and want to determine if fits my needs. Any
> pointers are appreciated. Will backup_size>tape_size work? Old
> backup routine... Weekly full backup on Fri and incremental
> Mon-Thu. Full~=20Gb"2tapes" and inc~=1Gb. Tape drive is
> dds3/12Gb. I read that amanda cannot handle backup>tape. So my
> first assumption is full>dds3 will fail. Elsewhere I read amanda
> spreads full/partial backups to many tapes. This makes me think
> full+(5*inc)<(5*dds3) which will pass.
>
>Thanks,
>
>Dale
The normal procedure for amanda is to attempt to spread the backup
out, mixing level 0's with incrementals in an attempt to use about
the same amount of tape each night.
The caveat about amanda not handlng backups > tape is not a realy
problem to most folks because you can specify not the whole drive,
but the individual subdirs on that drive in the disklist. Those
individual subdirs can usually be subdivided further it its
required, and its this individual disklist entry that is the limit,
not the whole disk, or even partition. For this reason, we usually
recommend using tar rather than dump becauce dumps granularity is
the size of the partition which can be a limit.
Amanda cannot span a single DLE across more than one tape because
when an EOT is hit, amanda will, if given permission to, advance to
the next tape. However, that particular file will be restarted
from the beginning on the next tape. If that file by itself is too
big, then it will repeat this until the magazine has been used up,
or it hits the "usetapes" limit.
When bringing up a system for the first time, its common to setup
the disklist file, but have enough of it commented out that whats
left is a bit less than a tapefull. Uncomment about that many
entries the next night, and the night after that, till they're are
all active. Then in a tapecyle or so, amanda will pretty much have
her own schedule worked out.
Once up and running, the recovery is the same, you will still need
the last "dumpcycle" tapes for a full uptodate recovery. If your
dumpcycle is say 7 days, then its the same as having one big friday
full, and 6 more incrementals to recover from
Because its just good sense to have more tapes than dumpcycle,
mainly so you aren't overwriting your last good backup with the new
one.
I may be doing a bit of overkill here. My dumpcycle is 5 days, it
runs 7 days a week, and I have 28 tapes in the rotation. Cheap
DDS2 tapes in ths case. I use about 3 of the 4 gigs each tape can
hold or a bit less on each run. My changer holds 4 tapes at once.
There is a bad version of tar about you should be aware of. If tar
--version returns 1.13 or less, you'll need a newer one.
Good luck!
--
Cheers, Gene
AMD K6-III@500mhz 320M
Athlon1600XP@1400mhz 512M
99.20% setiathome rank, not too shabby for a WV hillbilly
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