I have seen discussions on this list in the past talking about the need to
reduce the number of tape mounts on restore. They usually start out by
asking can ADSM perform full backups? Which in turn usually leads to
recommendations of collocating tapes. Then it is discussed how collocation
can lead to greatly increased tape mounts, tape wear & less efficient tape
utilization and is up to the admin. to weigh the benefits versus the cost.
What I am wondering is has it ever been suggested to lessen the impact of
data being spread over multiple tapes by making a couple of enhancements to
ADSM.

1. Since the bottleneck in many environments is usually the network, why
not have an option to use the disk storage pool space as a buffer for the
restore? ADSM would load the first tape and restore directly to the disk on
the server at disk & tape speeds. It could then go on to the next tape
loading data to the disk storage pool without waiting while data from the
1st tape is still being transferred to the client.

2. Multitask the restore process. DFHSM on OS/390 can restore an entire
DASD volume from an all incremental backup. Data could be spread out over
many tapes and could require a great many mounts to restore the volume.
This is very similar to ADSMs incremental without collocation. But hsm does
not perform collocation of this data, instead it was enhanced to allow the
admin. to specify how many concurrent restore task could run (up to 64,
provided you have that many tape drives).

It seems to me that these enhancements could allow the ADSM node to see a
constant stream of data coming across the wire during restore. The client
would not see all this recovery process happening in the back ground. Some
ADSM sites may then have an option to turn off collocation. Have these
improvements already been suggested? I would like to hear from others what
there opinion is on these.

Thanks,
Mike Wilson