We have a 16 GB at 65% filled.
No mirroring, but we got a large performance hit 
after using the MVS stripping feature
(every VSAM dataset spread over 16 volumes).
The performance gain was about 30% for some large sql selects

With regards 
Stefan Holzwarth

> -----Ursprüngliche Nachricht-----
> Von: Zoltan Forray/AC/VCU [mailto:zforray AT VCU DOT EDU]
> Gesendet am: Dienstag, 28. August 2001 19:57
> An: ADSM-L AT VM.MARIST DOT EDU
> Betreff: TSM for OS/390 poll
> 
> I am getting ready to reorganize my TSM on OS/390 
> configuration and was
> wondering how everyone else does it ?
> 
> For those folks running TSM on OS/390:
> 
> 1.   Do you MIRROR your DB ? If not, why not ?
> 2.   Is/was there a noticable difference/benefit when you 
> first MIRRORed
> the DB ?  Or did you start out MIRRORed ?
> 3.   How big is your DB ?  Mine is currently 17GB and 
> complaining about
> being over 85% utilized
> 4.   What if any pitfalls/negatives to MIRRORed DBs ?
> 
> ===========================
> Zoltan Forray
> Virginia Commonwealth University
> University Computing Center
> e-mail: zforray AT vcu DOT edu
> voice: 804-828-4807
>