Fred,

Mounting the filesystems containing DB and log with the dio flag can make a
huge performance difference on AIX.   It bypasses all the AIX read forward
and write behind stuff.  Just don't trust topas afterward as it bypasses
the stats there as well.

Regards

Steve

Steven Harris
TSM admin, Sydney Australia




             Mark Stapleton
             <Mark.Stapleton@C
             DW.COM>                                                    To
             Sent by: "ADSM:           ADSM-L AT VM.MARIST DOT EDU
             Dist Stor                                                  cc
             Manager"
             <[email protected]                                     Subject
             .EDU>                     Re: [ADSM-L] Strange behavior on
                                       DB(?) or Log(?)

             22/01/2009 11:07
             AM


             Please respond to
             "ADSM: Dist Stor
                 Manager"
             <[email protected]
                   .EDU>






From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Fred Johanson
We've got two machines which are identical in every way, same hardware,
same AIX, same TSM level, same options set, same storage pools, domains,
everything except one has the DB and Log on local disk.  On this box things
run very slowly: expiration may take a week, filespace deletion creeps, and
we see this as the normal behavior

All of the operations you describe above involve database and log
transactions. Since you've eliminated everything else, I would suspect
you've got substandard local disk (or possibly a corrupt database).

Since correcting a possible database issue will take a good deal of time
and effort, have you given thought to trying something easier, such as
putting the dbvols and logvols on SAN- or iSCSI-attached disk?

--
Mark Stapleton
System engineer, CDW



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