Pls, see the IBM Storage Web page.  They have a report about backing up a
huge Oracle data base (more than 500 GB) with 16 3590s simultaneously
attached to RS/6000.  It's very interesting. Hope this helps.
Rafael.

At 16:00 11/09/1997 EST, you wrote:
>     Hey- sounds like your talking with marketing.
>
>     I've got 8 3490E's in my 3494 and haven't seen any degredation since
>     the time I had only two.
>
>     If your 3590's will be scsi attached, please forward all 3590
>     performance numbers to the nearest junk bin.  During all of our
>     testing, scsi attached 3590's beat scsi 3490E by no more than 10%.
>
>     No bang for the $.  I was getting 4 meg/sec on 3590 vs 2.8 on 3490e.
>
>     BTW the 3490/3590 test was on standalone drives, each on a different
>     scsi bus, using sysback to backup raw devices.
>
>     ;(
>
>
>______________________________ Reply Separator
_________________________________
>Subject: How many 3590's can ADSM support?
>Author:  "Coleman; Barbara - WWH" <colemba AT WITCO DOT COM> at ~Internet
>Date:    9/11/97 12:12 PM
>
>
>I am thinking about getting 8 3590's in a 3494 library.
> Currently we are running 1 ADSM server on a wide node in an SP complex.
>
>An IBM rep. has told us that a single ADSM database can only drive up to 4
>tape units concurrently before performance degradation.  They also said that
>ADSM on AIX can only support the backup of 50GB an hour.
>
>IBM has recommended that we have at least 2 ADSM servers on 2 SP nodes. Each
>ADSM server would then be connected to 4 drives in the 3494. This is not a
>realistic solution for us.
>It also doesn't seem possible that it really is supposed to work like this.
>
>Our requirements are that we back up a 200GB database in 2 hours - (backup
>at a rate of 100GB/hr.) And, we want to be able to run all 8 tape units at
>one time with only 1 ADSM server.  Some tape units will be backing up other
>platforms at the same time that we are backing up the 200BG database.
>
>Does anyone have information about what ADSM will support?
>Is anyone using ADSM on AIX with more than 4 tape units? If so, what kind of
>performance are you seeing?
>Is anyone backing up 100GB/hr or more? How?
>
> -Barbara Coleman
>E-MAIL:  colemba AT witco DOT com
>
>

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