Stephen,

there is no any need to vary off the logical volumes. Moreover you cannot
vary off the LVs but only the whole VG. And you have no access to logical
volumes in varied off VG, only to the physical disks.
TSM itself does not care is you LV mirrored or not. The B/A client accesses
files on the filesystem created on top of the LV or makes a backup of whole
LV as a single raw data file using image backup. The TDP products access
the data through application APIs and again do not care about mirroring
done by the application or operating system.
The only products which do use something similar to this "split mirror and
backup" procedure are TDP products for ESS and EMC Symmetrix.

Zlatko Krastev
IT Consultant





"Greatbanks, Stephen P" <stephen.greatbanks AT EDS DOT COM> on 22.10.2001 
07:18:04
Please respond to "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
To:     ADSM-L AT VM.MARIST DOT EDU
cc:

Subject:        Client and AIX mirrored disks...

Hi,
        I am something of a TSM beginner, and this is my first post here
too, so please excuse
any obvious mistakes on my part.
        I am in the position of having to implement a TSM backup solution
for our client. This is (in the first instance at least) an all AIX shop.
I've read all the redbooks, and am pretty confident that I know (more or
less!) what needs to be done. However, I would appreciate some feedback
regarding AIX disk mirroring and how this affects the client-side of the
set-up.
        Without going into too much detail about our current config, are
there any special considerations regarding the client if you are using AIX
LVM-level mirroring? Our current backups use sysback/sbom which jumps
through a number of hoops to break a copy off the (triple) mirror, which is
then backed up whilst work continues. For simplicity, as much as anything
else, I would far prefer to not have to do this kind of thing as part of
the backup procedure. Is there anything in the TSM client which assists in
the backup of mirrored volumes? Do the logical volumes have to be varied on
(just wondering if varying them off is an option) for TSM to back them up?
Does anybody have any experience with this kind of thing?

Thanks in advance,

Steve Greatbanks
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