ON Tape... It take time to unwind, take the tape out, put another tape in
then start processing...
With Diskpool.  Thre is non of this.

My thought
Dave Pearson


> -----Original Message-----
> From: Orville Lantto [SMTP:orville.lantto AT DTREND DOT COM]
> Sent: Wednesday, July 24, 2002 11:03 AM
> To:   ADSM-L AT VM.MARIST DOT EDU
> Subject:      Re: diskpool performance
>
> What are your throughput values?  Tape is not necessarily slower than
> disk, especially when the data is compressed on the tape drive.
>
> Orville L. Lantto
> Datatrend Technologies, Inc.  (http://www.datatrend.com)
> IBM Premier Business Partner
> 121 Cheshire Lane, Suite 700
> Minnetonka, MN 55305
> Email: Orville.Lantto AT datatrend DOT com
>
>
>
>
>
> Steve Freeman <sfreeman AT ACRLIMITED.CO DOT UK>
> Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
> 07/24/02 11:00 AM
> Please respond to "ADSM: Dist Stor Manager"
>
>
>         To:     ADSM-L AT VM.MARIST DOT EDU
>         cc:
>         Subject:        diskpool performance
>
>
> Please could someone advise me on the following issue we have with tsm.
> I am a TSM novice and would appreciate some pointers etc.
>
> Environment :  TSM 4.2.0  AIX4.3.3 ML09 Server and Client on same Server
> using Sharedmem
>
> 2 Stgpools defined diskpool and tapepool
>
> we have created a diskpool on RAID5 and created random access volumes
> Total Diskpool size is 150GB. Our nextpool is tapepool for migration
> upon high thresholds being reached.
>
> We have compression turned off on the client  and set the selftune
> parameters in dsmserv.sys
> SELFTUNEBUF
> SELFTUNETXN
>
>
> Issue:  IF we initiate a client backup using sharedmem to the diskpool,
> it seems to take the same time as it does to backup the client straight
> to tapepool. I would have thought the diskpool access
> would be quicker ?
>
> The Diskpool is located on direct fibre attached storage with large
> read/write cache. The tapepool
> is SCSI attached ATL library with 2 drives
>
> Any suggestions or pointers to increase the throughput to a respectable
> level would be appreciated.
>
> kind regards
> steve freeman
> sfreeman AT acrlimited.co DOT uk