On Mon, Feb 13, 2006 at 03:30:54PM -0600, Salvatore Enrico Indiogine wrote:
> Question 3:
> 
> >From reading the documentation it seems that I have to backup a
> complete filesystem and can not simply define a b/u directory like a
> /home/user1
> 
> Is this correct?

bru, I think, uses its own proprietary backup program.
Amanda uses either your client's dump/restore programs
or, at your option on a DLE by DLE basis (disklist entry),
uses gnutar for both backup and recovery.

Thus, you are constrained by the capabilities of the
backup program.  Few, if any, dump/restore pairs are
designed to deal with anything except complete file systems.
Gnutar can.  So for each DLE, you pick which you want.

> 
> 
> Question 4:
> 
> The tapedevice is:
> 
> define tapetype SDLT320 {
>      comment "HP Super DLTtape I, data cartridge, C7980A"
>      length 139776 mbytes
>      filemark 0 kbytes
>      speed 13980 kps
>  }
> 
> I obtained the specifics from the Amanda wiki.  When I define the b/u
> job in the dump type definitions section of amanda.conf do I need to
> specify any compression?   I do not think that the tape drive does
> any.  At least with BRU you do not need to worry about that setting.

Gee, bru must not be as flexible.  With amanda you can use no compression,
the tape drives compression (hw) or a compression program, gzip (sw).
For sw, seemingly the favored way for amanda, you can do the compression
on the client or on the server.

> 
> Question 5:
> 
> I have also read that amanda is not able to append to a tape.  At the
> moment the incrementals and differentials write to the same tape for
> the same b/u job.   If I can not append to the tape do I need to
> change them after each incremental?   I think I am not understanding
> this correctly.

The designers of amanda decided that it is too risky to add to a tape.
One small error in positioning could wipe out all your backups on the
tape.  You can let the backups collect on disk (in the holding disk area)
and only "flush" them when you have sufficient to fill a tape.

This phrase:

> do I need to change them after each incremental?

tells me you don't yet understand the amanda scheduling.  It is
definitely not bru.  You don't have incrementals today, fulls
tomorrow.  Each day is a mixture of some DLEs as full, some DLEs
as incrementals.  The aim is to have the size of each day's backup
be approximately the same.  Don't you hate when your Sunday backup
takes 14 hours and every other backup takes 1?  Well with amanda
they will all take 3 hours.  (numbers made up)

-- 
Jon H. LaBadie                  jon AT jgcomp DOT com
 JG Computing
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