On Mon, Feb 09, 2004 at 03:01:21PM -0500, Eric Siegerman wrote:
> I want to make two identical copies of an Amanda backup.
> 
> I have enough holding-disk space to hold all of the client's DLEs
> at once, so what I'm thinking is this:
> 
>  1. Build a new Amanda configuration that backs up only the client
>     in question (reserve=0; also record=no to be on the safe side)
> 
>  2. Run the configuration with no tape in the drive, forcing all
>     the (full) backups to holding disk
> 
>  3. Hard-link the holding-disk files to another directory that
>     Amanda doesn't know about
>  
>  4. Run amflush
> 
>  5. Hard-link the holding-disk files back to the Amanda spool
>     directory (it's pure paranoia that I choose not to mv them
>     instead and thus dispense with step 7)
> 
>  6. Run amflush again
> 
>  7. Delete the holding-disk files from the other directory
> 
> Does this look like a reasonable approach?

Since nobody raised any red flags, I went ahead and tried this.
It worked flawlessly.

> My main worry is that
> the curinfo database and multiple amflush's of the same data
> won't get along with each other.  Is that likely to be a problem?

This didn't turn out to be an issue.  The only effect I could
find on the database was that when I amflushed the second copy
(step 6), "amadmin info" forgot about the first one.  But this is
a minor quibble, and I'm *not* suggesting that anything needs to
be done about it.

    amserver 3# amadmin archive info foo c0t4d0s4

    Current info for foo c0t4d0s4:
      Stats: dump rates (kps), Full:  629.0,  -1.0,  -1.0
                        Incremental:   -1.0,  -1.0,  -1.0
              compressed size, Full:  94.8%,-100.0%,-100.0%
                        Incremental: -100.0%,-100.0%,-100.0%
      Dumps: lev datestmp  tape             file   origK   compK secs
              0  20040209  archive.foo_before_reinstall.20040210.copy_2.tape_1  
   2 1308351 1240741 1972


"amadmin find" gets it right -- it reports both tapes:  

    amserver 4# amadmin archive find foo c0t4d0s4 | more
    Scanning /var/spool/amanda/holding-disk-archive...

    date       host   disk     lv tape or file                                  
         file status
    2004-02-09 foo    c0t4d0s4  0 
archive.foo_before_reinstall.20040210.copy_1.tape_1    2 OK
    2004-02-09 foo    c0t4d0s4  0 
archive.foo_before_reinstall.20040210.copy_2.tape_1    2 OK


In summary, I wouldn't recommend doing it this way on a regular
basis -- RAIT and a second drive would be easier and less
error-prone.  But I only needed to do a single two-copy backup;
in that situation, if you have enough holding-disk space, this
approach is hard to beat.

(And no, my regular backup tapes don't have weird names like
that; they're Weekly.[0-9][0-9][0-9].  But for permanent archival
tapes, I thought, why not make them as self-identifying as
possible?)

--

|  | /\
|-_|/  >   Eric Siegerman, Toronto, Ont.        erics AT telepres DOT com
|  |  /
It must be said that they would have sounded better if the singer
wouldn't throw his fellow band members to the ground and toss the
drum kit around during songs.
        - Patrick Lenneau