> 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]>



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[email protected]
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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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