On Thu, 5 Sep 1996 09:15:19 -0400, Peter Talajic wrote:
>- RS/6000 (model 520H)
>- 3 x 2-gig drives (fast and wide)
>- 2 x 1-gig drives
>- EXB-120 robot having 116 x 8mm tapes.
>
>The clients we currently backup are:
>
>- 20 unix servers
>- 25 Novell servers
>- 1 NT server
>- 200 desktop computers, mostly Windows 3.1/95 and some Macintosh

>1.  What number of tape/disk devices per SCSI controller do people suggest
>one uses with the server, i.e., to maximize throughput?

I have never used RS/6000s, but I am sure it must have some type of
RAID. Try to get RAID 5 or any RAID with stripping. From reading this
list, and my own experience, it seems the ADSM databases and logs are
not accessed in parallel or round-robbing fashion. It seems they are
accessed in a sequential form. If you have a mirror of a backup
database or log you can run those in parallel, but I am referring to
any additional database that you may create when you run out of space
in your existing database.

>2.  Are there any suggestions as to how we should organize our disk storage
>pools and database?  By this I mean:  Are there any advantages in locating
>storage pools and database components onto (A) the same physical disk (B)
>their own physical disk, or (C) it doesn't matter

Again going with RAID is your best bet. If you don't have RAID, but
can have different  SCSI controllers, then create pools across two
disks. You may get more performance by going across more disks, but
then you increase your point of failures.

>3.  Does anyone make use of and/or have opinions concerning DLT drives?

With the little time we have had one (a few months) it is working
fine and faster than 8MM.

>4.  What do people think of MagStar or any other types of robotics?
I don't know much about autochangers, but I wanted to point out that
you could continue using the EXB-120 and buy an additional DLT
changer. For instance you could use the 8mm for backing up your
desktops and the DLT for your servers.