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
