Hi Chris

On 13/08/09, Chris Hoogendyk (hoogendyk AT bio.umass DOT edu) wrote:
> ... the solution is akin to the Japanese monks caring for Bonzai....

I liked this idea about tape archives -- constant pruning and
maintenance. Difficult to sell though.

> As for your specific questions:
> 
> You should be able to do LVM snapshots. I use fssnap on Solaris 9 and
> 10, and scanning through, here are just a couple of references I find
> to people using LVM snapshots with Amanda:
<snip>
> With the latest releases of Amanda, there is a new API that could make
> it even easier to implement.

Great; thanks for the pointers.

> Typically, we set up Amanda with holding disk space.
<snip>

If all the storage is locally attached (actually, AoE drives storage
units connected over Ethernet), I am hoping to avoid the disk space if I
can write to tape fast enough. I'd like to avoid paying for up to 15TB
of fast holding disk space if I can avoid it.

> Compression can be done either on the client, on the server, or on
> the tape drive. Obviously, if you use software compression, you want
> to turn off the tape drive compression. I use server side
> compression, because I have a dedicated Amanda server that can
> handle it. By not using the tape drive compression, Amanda has more
> complete information on data size and tape usage for its planning.
> If your server is more constrained than your clients, you could use
> client compression. This is specified in your dumptypes in your
> amanda.conf.

I don't have any clients, so this is an interesting observation. I'll be
trying to do sofware compression then I think. The Unix backup book
(google for "amanda software compression") suggests that compression can
be used on a "per-image basis"; presumably I can pass the backup data
stream through gzip or bzip2 on the way to a tape?

> Deduplication is not available with Amanda. However, some people
> stage different kinds of tools and use Amanda for the final staging
> and management of tapes and archives. So, in some situations,
> BackupPC could be used to do deduplication from, say, desktop
> clients to a server archive which is then backed up by Amanda. That
> could start complicating your 12 year recovery scenario and what
> happens when software is not available or doesn't run.

Great -- thanks for the details.

> Amanda uses the term "index" rather than "catalog" -- see
> http://wiki.zmanda.com/index.php/Amanda_Index.
> 
> Note that if you are putting tapes into a long term archive with no
> intent of recycling them in subsequent backups, you can use amadmin
> to mark them as no-reuse. I periodically (typically at the end of
> semesters) do a force full, mark the tapes as no-reuse, and then
> pull them out of my tapecycle and put them in storage.

Very useful again, thanks.

Regards
Rory
-- 
Rory Campbell-Lange
Director
rory AT campbell-lange DOT net

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