load balancing across device pools with partitions?

[rpatty]

Is there a way to have a device pool which load balances across two tape drives, but which excludes a partition on one of the drives?

I've got two drives, call them Drive A and Drive B. Before I had any partitions, it was easy to put both drives in a device pool, assign a job to the pool, and let the CASO hand out the job to either drive without trouble.

But now I've added a partition to Drive A, because we've got some database backups that need to be handled completely differently. So on Drive A we've got Partition 1 which has two slots for the databases, and Partition 2 which covers all the other slots. However, the device pool just sees the two drives, and not the partitions. I'd like to know how to continue using the CASO to load balance across both drives, but to avoid Partition 1. Is that possible?

[VJware]

I know manual duplicate jobs would not list the partitions in CASO setup , but do not recall for regular backups..lemme double-check..

[rpatty]

Just for reference, I'm attaching what I see. If I create a new device pool, it lets me choose from the two drives, but appears to be unable to recognize the partitions in Drive 1. I'm worried if I assign a job to a pool with both drives, it might try to write jobs to both partitions on Drive 1, mixing up all our other data with the database data.

[VJware]

from the Devices tab, are you able to right-click on the partition & choose add device..

similar to http://www.symantec.com/docs/TECH76823

[VJware]

right...so rt the partition..choose add device...select your Drive A & complete the process

[rpatty]

I'm only shown those two devices, just like the picture above. It doesn't appear to be able to see the partitions.

Edited to add: if I click on a partition and try to add device, it says no other devices are available to be added. Looks like I can't add Drive 2 to a partition that's on Drive 1.

[rpatty]

Sorry for the double post, but I was editing my response as you'd replied again, so I'll repeat, just to make sure you don't miss it:

If I click on a partition and try to add device, it says no other devices are available to be added. Looks like I can't add Drive 2 to a partition that's on Drive 1.

[Ken_Putnam]

Looks like I can't add Drive 2 to a partition that's on Drive 1.
 

Partitions are not associated with physical drives.  

If you have a loader with two drives and four partitions, a job running on either drive should be able to access all four partitions - if you just point the job at the loader as a whole, rather than just one partition

[rpatty]

So my question was, what if I want to EXCLUDE one of those partitions? I need to point at both drives for load balancing and failover, but I only want to use one of two partitions for that function.

[Kiran_Bandi]

I'd like to know how to continue using the CASO to load balance across both drives, but to avoid Partition 1. Is that possible?

When you create partitions in a robotic library, BE automatically creates a seperate device pool for each partition. Target your jobs to those device pools not to default pool. So a job targeted to partition 2 will exclude partition 1.

And if two jobs are running at one partition at the same time, both the drives will be utilized. (If LEO licensed)

[rpatty]

That doesn't really help me load balance, though. If I pick one pool, it's stuck on that one server only. I'd like to be able to pick Drive A Pool 2, and ALSO Drive B, while avoiding Drive A Pool 1.

[rpatty · Accepted solution]

So I found another thread here:

https://www-secure.symantec.com/connect/fr/forums/partition-configuration-ignored-some-jobs

Which claims:

If a job is targeted to a particular robotic library drive (or a device pool that is not a partition drive pool), the job defaults to the first partition in the robotic library.

This says to me if I set the partition I want to exclude to Partition #2, then I can point to both Drive A and Drive B and it'll properly grab Partition 1 on Drive A, while ignoring Partition 2 on that drive, and still load balance/failover with Drive B. This would give me exactly what I want, if it's true.

Can anyone confirm or deny if this is accurate?

[rpatty]

Just in case anyone else runs into this issue, wanted to follow up. After a few weeks this theory appears to hold. All the jobs assigned to the larger pool that got assigned to Drive A have have gone to the first partition and left the second partition alone.