I am in the process of setting up a 2TB disk "staging" storage unit.
Because Solaris has a 1TB filesystem limit for I had to set up
3 partitions which I then defined as individual storage units in
a storage unit group.  I have tried both the disk-staged storage
unit and the disk storage unit using locally written scripts.

Neither configuration works the same way as storage unit groups
comprised of tape libraries with drives and Veritas will not have
a fix until NBU 6.0 not due out for another 6 months.

What happens is that when the initial storage unit gets full,
the currently active backups using the unit fail with a media write
error and will not continue onto the other available disk storage
units.

With the disk-staged storage units, the staging from disk to tape
was immediate, but the expiration and removal of the disk image was
not, and this behavior is not configurable (I have no idea how
NetBackup determine that the storage unit is full to let the
expiration and removal commence).

With just plain disk storage units, the active backups also got
media write errors and would not continue to the other available
storage units.  Once a backup failed, it would continue to fail until
diskspace on the initial storage unit was available.

Basically, I've now de-configured the storage unit group and now
have 3 disk storage units.  I'm using one storage unit for incremental
backups and the other 2 for full backups.  I've had to configure
each policy schedule to use specific storage unit.  I'm using a locally
written script to stage/expire/remove diskimages because I need
more control over the clearing of the diskspace.

Needless to say, I'm disappointed that Veritas released such inflexible
storage unit options without any mention of the known limitations.
Right now, I'm finding disk storage units to be an administrative
nightmare.

I do have to say that disk storage units would have been much less of
a nightmare if I were not limited to a 1TB filesystem size (a
restriction which will be removed in Solaris 10) and if the storage
array were large enough to hold more than 1 days' worth of backups
(a limitation caused my a very small budget).

On Thu, 14 Apr 2005 veritas-bu-request AT mailman.eng.auburn DOT edu wrote:

> --__--__--
>
> Message: 11
> Date: Thu, 14 Apr 2005 16:54:57 -0700
> From: Tim Berger <tim.berger AT gmail DOT com>
> Reply-To: Tim Berger <tim.berger AT gmail DOT com>
> To: "veritas-bu AT mailman.eng.auburn DOT edu" <veritas-bu AT 
> mailman.eng.auburn DOT edu>
> Subject: [Veritas-bu] Disk storage staging unit groups, anyone?
>
> We're on nbu 5.1 MP2.
>
> I am curious about the behavior of disk storage staging unit groups
> with respect to when a storage unit is chosen and when staging space
> is freed up.
>
> I am interested in setting up a staging group consisting of several
> disk staging storage units, but I don't want space freed up if there
> is still space free on storage units in the group.
>
> Humm.  Is anyone out there doing this?
>
> I suspect that I'm out of luck.  The docs state that the "first
> available" storage unit is selected, which probably means that a full
> but inactive disk staging storage unit will be chosen.
>
> I suppose an alternative to this would be making really big staging
> storage units with lvm or some such; or take more care when assigning
> clients to policies and policies to staging storage units.
>
> Thanks.
> --
> -Tim
>
>
>
> --__--__--

--kathy