Maybe I should have clarified my intent.

The reason I am looking into mirroring is for PERFORMANCE, not necessarily
recovery.  When I went to my first ADSM class, they talked about mirroring
for performance (although for the life of me, I could not understand how
having to perform 2-write operations versus 1, would speed anything up.
Yes, I realize the read part should be faster since numerous read
operations could be spread over the 2-mirrors ).

We too are completely raided. DASD/hardware issues are not the concern.





"Brian L. Nick" <BRIAN.NICK AT PHOENIXWM DOT COM>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
08/28/2001 02:09 PM
Please respond to "ADSM: Dist Stor Manager"


        To:     ADSM-L AT VM.MARIST DOT EDU
        cc:
        Subject:        Re: 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 ?

     No. We are comfortable with the reliability of the mainframe DASD
     and it's own recovery.

2.   Is/was there a noticable difference/benefit when you first MIRRORed
the DB ?  Or did you start out MIRRORed ?

     Never mirrored.

3.   How big is your DB ?  Mine is currently 17GB and complaining about
being over 85% utilized

     Our TSM DB is 37.5gb 73% utilization.

4.   What if any pitfalls/negatives to MIRRORed DBs ?

     I can't answer that question as we were never mirrored.

===========================
Zoltan Forray
Virginia Commonwealth University
University Computing Center
e-mail: zforray AT vcu DOT edu
voice: 804-828-4807