>Question: Can amanda work as a tape manager for machines that
>share a tape device (or tape library)?
That depends entirely on the underlying OS. All Amanda does is issue
plain file system operations (open, read, write, close) and a few well
defined ioctl's (fsf, rewind, etc). If your OS doesn't mind other people
"on the wire" at the same time, Amanda certainly won't care.
>I'm hoping that I would be able to have 10-12 machines in the fabric,
>and let amanda tell them when it's ok for them to backup to the tape
>device (that appears to be a local device, but is actually shared by
>all of the machines).
I'm confused (already :-). Amanda typically thinks it owns a tape
drive while it's being used. So are you going to run a separate
Amanda configuration on each machine? If so, then you would either
need something above Amanda controlling which configuration runs when,
or you could accomplish this with a custom tape changer script (which
are pretty easy to write).
>1) if all of the scsi devices get exercised during a boot up, that could
>problems if a backup is happening and one of the other machines boots up
I'd be more worried about the SCSI reset that will go to the drives.
That will kill any operation and force a rewind.
>(This is not really an amanda issue, though-- I'm mostly hoping that
>someone on the list has enough experience with tape libraries to let me
>know if this could cause a problem.)
My library (ATL 2640) doesn't do anything special at boot, at least with
respect to the drives. I suppose it gets a reset and if it happened
to be moving something at the time it might get snitty. Since I'm on
a single access, I've never noticed.
>Here is the configuraton I think I would use:
>1) Host BigBoss -- configured as amanda server
>2) Host anyClient -- configured with "--with-index-server=BigBoss --with-tape-
>server=localhost"
The --with-index-server and --with-tape-server options only deal with
amrecover. They have nothing to do with amdump reaching out to a client
to back it up. That's controlled from the server side in the disklist
file, which tells the server which clients to reach out to.
>What's more unclear to me is how I would actually configure the backups
>(ie. one configuration that instructs the client to request _any_ slot,
>or 3 configurations with fixed drives; and one drive kept in reserve for
>doing emergency restores).
Clients (in Amanda terms) do not request tapes. Only the tape server
does that. Clients send their data across the network to the server who
(optionally) drops it in a holding disk and then writes it to tape.
My first shot at this (after I tested the reset problem -- a **lot**)
would be to designate one to four machines as Amanda tape servers and
have them either cooperate on picking a drive to use or just hard
allocate them. Each server would back itself up. Then parcel out
the rest of the machines as clients to the servers (remembering that a
client may only talk to one server, i.e. you cannot give a few disks on
a machine to one server and the rest to another).
Just what is the fibre channel buying you, or, put another way, what
is you're really trying to accomplish? I admit to a) not knowing much
about fibre channel and b) not being much of a fan since the couple of
times it's been used around here it was terrible.
>-ron
John R. Jackson, Technical Software Specialist, [EMAIL PROTECTED]
