Joshua,

The db and log are spread out among 8 Logical Subsystems.

Eliza
>
> Eliza,
>
> How many ranks (Logical Subsystems) is your DB and log spread out
> across?  For highest performance, try spreading the load across as many
> spindles as possible.
>
> --
> Joshua S. Bassi
> IBM Certified - AIX 4/5L, SAN, Shark
> Tivoli Certified Consultant - ADSM/TSM
> eServer Systems Expert -pSeries HACMP
>
> AIX, HACMP, Storage, TSM Consultant
> Cell (831) 595-3962
> jbassi AT ihwy DOT com
>
>
> -----Original Message-----
> From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf 
> Of
> Eliza Lau
> Sent: Wednesday, September 18, 2002 9:28 AM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: backup performance with db on the Shark ESS
>
> I posted a message a month ago about performance degradation after
> moving
> the db and the log to the Shark ESS.  The problem has been resolved with
> help from Paul Seay.  Here is a recap:
>
> Moved 32G db and 10G log from attached SCSI non-RAID disks to IBM Shark
> ESS.
> Kept 2 copies of db and log.  I wasn't ready to drop the security
> blanket.
> Backup db increased from 40 minutes to 90 minutes.
> Reformat the AIX volume group that the db was on from 2 LUNs to 8 LUNs.
> Backup db still ran for 90 minutes.  The additional LUNs didn't help at
> all.
> Dropped the second copy of the db and log.
> Backup db now runs for 24 minutes.
>
> Paul told me that there is a fix in 4.2.2.8 for performance of backing
> up
> 2 copies of the db.  I will try setting up a second copy of the db after
> I
> upgrade to 5.1 in a few months and see if it makes a difference.
> Meanwhile, I am keeping only 1 copy of the db and 2 copies of the log
> and depending solely on RAID-5 of the ESS for the integrity of my db.
>
>
> server: TSM 4.2.1.15 on AIX 4.3.3
>
> Thanks to all the people who contributed,
>
> Eliza Lau
> Virginia Tech Computing Center
> 1700 Pratt Drive
> Blacksburg, VA 24060
> lau AT vt DOT edu
>