We also had the need to send a portion of our backups directly to a tape,
for long-term retention.  We found that the newer tape drives are faster
than the network, so the tape was "stalling" a lot.  This not only impacts
performance, it is also hard on the drive.  The solution we chose was to
send the files to a disk pool, which migrated to the tape.  Before the
backup starts, the high migration threshold on the disk pool is set up (we
chose 70%), so that if it rolls to tape the drive will be able to stream for
a while before running ahead of the backup.  Once the backup process is
completed, the high migration threshold is set back to zero, which flushes
the disk pool entirely.  The migration thresholds are set with
administrative command schedules, with a generous time margin to ensure the
backup is completed before being set back to zero.

Essentially, sending your backup to tape may not be the best solution.

Question to those who felt this request was too simple:  I am new to this
forum, and have only been using ADSM for a few months.  What criteria should
I apply when deciding whether to submit a question?

Dan Ticknor
Schnitzer Steel

> -----Original Message-----
> From: Hon Wai Wong [SMTP:hwwong AT HHITS DOT COM]
> Sent: Tuesday, November 17, 1998 1:19 AM
> To:   ADSM-L AT VM.MARIST DOT EDU
> Subject:      howto backup to tape
>
> Hi all:
>
>     I  am new to ADSM. I have installed ADSM server at one of the machine.
>       And is able to access it thru webpage.
>
> I wish to backup to tape. The default is to disk. How should I go about?
>
> I guess tape is sequential access storage pool. thus I add tape in it. But
>       it asked for device_class_name. I do not know what
>
> should I put in that field.
>
>
>
> Please advise.