Mike,
Yes, I know that I'm only going to get full-pack backups. This
is a temporary solution for the span of about 3 months. The project
involves migrating from 3.1 to 5.4 at which point CMS-level backups will
be done.
Thank you for your comments. As always, you folks are quite
knowledgeable and VERY helpful.
Regards,
Dave
-----Original Message-----
From: The IBM z/VM Operating System [mailto:[email protected]] On
Behalf Of Mike Walter
Sent: Monday, September 20, 2010 2:22 PM
To: [email protected]
Subject: Re: DEDICATED DASD - How to backup?
> I have a maintenance window of two days a month in which I COULD
shutdown the guest, but it'll meet with resistance I'm sure.
Will shutting it down to get the backups meet with any more resistance
than the system not being able to run after a restore has been
performed?
What you suggest is backing up one running system from a 1st level
system
that has no idea of the filesystems on the 2nd level system. Sure,
VM:Backup on the 1st level system knows about CMS files - as long as the
minidisks are defined to the 1st level system. But that 2nd level
system
has it's own CP Directory which cannot tell VM:Backup where the 2nd
level
systems minidisks start and end, or even who owns the minidisks.
So... at best you'll get full-pack "physical" backups from VM:Backup, or
from any other product or tool. That's: read a DASD cylinder of bits,
write a DASD cylinder's worth of bits to tape. No file-level restores,
just whole cylinders. And consider also that the applications on that
2nd
level system may be writing to several difference minidisks on different
DASD. The VM:Backups will be inconsistent, since the minidisks will be
backed up when the app is writing data at different times than the
individual cylinder backups are made. That's why database products have
their own backup tools - they can ensure a consistent backup.
Is there any reason that the 2nd level system could not have VM:Backup
installed on it to run its own backups? Yes, you'd have to attach tape
drives during the backups, but that is do-able. And if you are using
VM:Tape, that 2nd level system would need to have VM:Tape installed as
well - again, that's do-able. And that would require any added
licensing
costs system the CA products are still running on the same physical
CPUID.
All that said... for many years we had the MVS sysprogs make FDR backups
up the VM system DASD, while the VM system was up and running. At no
point during any of the (perhaps) 15+ semi-annual D.R. tests were we
unable to bring up the VM system once the MVS sysprogs had FDR-restored
the VM DASD. After a few tests I grew more leery (see the
database/multi-minidisk considerations above). So we ran extensive CMS
filesystem utility checks on every single minidisk looking for
filesystem
errors. None were ever found. We eventually switched to running VM's
own
VM:Backup D.R. backups (after the MVS guys stopped running any more VM
DASD backups w/o telling us - twice!).
Mike Walter
Hewitt Associates
The opinions expressed herein are mine alone, not my employer's.
"KEETON Dave * SDC" <[email protected]>
Sent by: "The IBM z/VM Operating System" <[email protected]>
09/20/2010 03:55 PM
Please respond to
"The IBM z/VM Operating System" <[email protected]>
To
[email protected]
cc
Subject
Re: DEDICATED DASD - How to backup?
I have a maintenance window of two days a month in which I COULD
shutdown
the guest, but it'll meet with resistance I'm sure. The hope was to back
it up daily. There's a total of 42 3380 volume currently.
As to the OS, it's VM 3.1 ... yeah, old stuff! We're migrating a
customer
from their old mainframe. This is a temporary solution.
Dave
From: The IBM z/VM Operating System [mailto:[email protected]] On
Behalf Of Gentry, Stephen
Sent: Monday, September 20, 2010 1:53 PM
To: [email protected]
Subject: Re: DEDICATED DASD - How to backup?
Can the guest be shutdown to do a backup? If so, try defining a full
pack
minidisk on the dedicated drive and then use vm:backup to backup the
minidisk.
Does the guest OS have a backup utility? (You didn?t mention what the
OS
of the guest is).
From: The IBM z/VM Operating System [mailto:[email protected]] On
Behalf Of KEETON Dave * SDC
Sent: Monday, September 20, 2010 4:48 PM
To: [email protected]
Subject: DEDICATED DASD - How to backup?
I have a guest OS running on 3380 DASD. All of the DASD is defined with
DEDICATE statements to that guest only. I'm now trying to determine how
to
backup that guest. I have the CA VM:Backup (with HiDRO) product, but I'm
told it probably won't work because the guest has no minidisks. We have
a
VTS here, so all the data will be written to virtual tape using the
DFSMS/VM (RMS) and CA's VM:Tape.
Does anyone have any suggestions?
Thanks in advance,
Dave Keeton
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