Hello Tom,
I have not noticed the 100 during the batch processing but I
will ask the operators to keep an eye on it.
Ed Martin
330-588-4723
ext 40441
-----Original Message-----
From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On
Behalf Of Tom Duerbusch
Sent: Wednesday, July 16, 2008 11:26 AM
To: IBMVM@LISTSERV.UARK.EDU
Subject: Re: FLASHCOPY performance to a DS6800 DASD
Hi Ed
Yep, it is amazing, especially for those of us that never had access to
a high performance dasd subsystem before.
Without the sync parm, the command comes back immediately. With the
sync parm, the command comes back when the DS6800 has gathered all the
information/control blocks necessary, and starts the flashcopy.
I've never been able to determine when a flashcopy is completed, other
than looking at the lights on the box. That has been a problem as if
you need to rerun the flashcopy command again (like something bombed out
in the rexx exec and it is easier just to reexecute the exec), it tells
you that the "to" volume is in use. So if you have a mixture of large
and small volumes, the small volumes get a repeat of being flashed and
the large volumes end up with the original flash.
There is suppose to be a way from the DS6800 console to determine what
flashes are running, but I never got that far. Also, if you want to
flash a series of volumes at the same instant, it can be done via the
DS6800 console.
I flash minidisks, so I can only use the VM Flashcopy command.
BTW, have you noticed that when you run batch jobs, you are always near
100% cpu utilization? My boss keeps asking me who is in a loop. We are
running just fine <G>.
Tom Duerbusch
THD Consulting
Law of Cat Acceleration
A cat will accelerate at a constant rate, until he gets good and
ready to stop.
>>> "Edward M. Martin" <[EMAIL PROTECTED]> 7/16/2008 8:59 AM >>>
Hello Everyone,
I need some confirmation. I am just amazed at the performance of
the DS6800
I just did the z/VM command FLASHCOPY on a 3390-mod 9 on DS6800 to
another 3390-mod 9 volume on the DS6800.
FLASHCOPY 8A2 0 END TO 8A1 0 END SYNCHRONOUS
The command responded instantaneously.
SYNChronous
tells CP to process the command immediately and does not allow you
to
enter any other commands until the hardware has accepted all
parameters,
all messages from the Enterprise Storage Server (ESS) subsystem have
been
processed, and the FLASHCOPY command completes.
Is the DS6800 and the FLASHCOPY really that fast or is there something
going on behind the
scenes?
Performance has been pretty unbelievable but the FLASHCOPY was just too
fast.
Example Our Batch cycle at night use to take 5-5.5 hours. Started at
midnight and
Completeed around 5:30 am.
Old system EMC SYMETRIC 8 gig of cache and 6 ESCON connections.
SWITCH to DS6800.
DS6800 2 gig of cache with 4 FICON connections.
Batch cycle dropped by 1 hour without any other changes. Start at
midnight and completes
around 4-4:30 am.
Ed Martin
330-588-4723
ext 40441
