Yes, but don't expect sparkling performance.

Even with striped disk for the storage pools, I cannot even match ONE session to
tape when going to disk. I use SSA disk from an AIX Super Wide SP2 node, and get
about 6.5MB/s to 3570 tape, and not more than 5MB/s for a single session when
writing to disk. I expect this performance to drop significantly with multiple
concurrent sessions. My best suggestion is to set a NEXTPOOL parameter in the
disk pool to point to the tape pool, and MAXSIZE (I think this is the parameter)
to force large files to be written direct to tape, and small ones to be backed
up to disk.

Please also be aware that if you are using DRM, it is necessary to manually
migrate the data from the disk pools before you do the copy stgpool for your
offsite copies. This takes extra time.

Peter Gathercole
Open Systems Consultant

Prather, Wanda wrote:

> You've got the right idea.
> If you are backing up direct to tape, you need a tape drive for every active
> client.
>
> Back up to disk, and let ADSM control the migration of data to the tape
> drives.
> Then you should be able to get your 30 simultaneous sessions.
>
> In the parms for your disk storage pool, you can set thresholds than control
> when migration starts.
> And you can set the maximum number of migration processes to 3 or 4, so ADSM
> will use more than 1 of the drives at once for migration.
>
> ***************************************************************
> Wanda Prather
> The Johns Hopkins Applied Physics Lab
> 443-778-8769
> wanda_prather AT jhuapl DOT edu
>
> "Intelligence has much less practical application than you'd think" -
> Scott Adams/Dilbert
> ***************************************************************
>
> > -----Original Message-----
> > From: Marc Layne [SMTP:mlayne AT FGH.CO DOT ZA]
> > Sent: Tuesday, December 08, 1998 9:19 AM
> > To:   ADSM-L AT VM.MARIST DOT EDU
> > Subject:      Maximum Client backup sessions
> >
> > Hi All
> >
> > I'm sure there is quite an easy answer to this but I cannot seem to find
> > it
> > anywhere...
> > I have a client that wants to backup approx. 30 clients simultaneously to
> > an ADSM v3.1 server.They have a 3575 L24 library (yuck) attached to the
> > server with 6 drives (two used for Informix logging) and 4 for backups.
> >
> > They are backing up directly to tape currently. They are not able to
> > backup
> > more than 4 clients simultaneously even though the maxsessions parameter
> > is
> > set to 40.The first 4 clients grab the four drives and the others are
> > unable to run. I have considered backing up to DISK first to alleviate
> > this
> > problem. Is there something I am missing?? Can you backup to tape more
> > clients than there are drives without backing up to disk first?? If so
> > where can I find the information or is there a parameter I have to change
> > .. Help Please.....
> >
> > Tx Marc