Drive pool won't use all drives

[DrDebate]

Greetings!

I am using BE 2010 R3 to back up our Exchange server.  As the size of our storage groups grew I no longer had enough storage space on the BE server to cover the backups.  I added additional storage and created a device pool with all three Backup-to-Disk locations (previously there was only one).  I also split up the backup job into two.  I then changed the device in the job setups to use the pool instead of the original single backup-to-disk device.  The problem I have is the job still goes to the initial backup-to-disk device and then immediately fails as it is full and nothing is overwritable yet.  It is ignoring the two new devices in the pool.  However, the second backup job used one of the new devices.  Am I doing something wrong here?

[pkh]

When you use a device pool, BE will use the first available device in the pool which is what your first job does.  The second job used the second device because the first device has been marked as full by the first job.  This behaviour is to be expected.

If you have all three devices on-line at the same time, you can turn on disk spanning.

Once the low disk threshold limit is reached, BE will use the next device in the pool.  Note that this disk spanning is only good for .bkf files.  If you are using GRT which uses .img files, then the spanning will not work as .img files cannot be split across devices.

If the media on your first device are not overwriteable yet, you should make the device off-line until they are overwriteable, then bring it on-line for BE to overwrite them.

[yusufusmani]

All the above explained by pkh is correct, but if you have 3 devices in pool, it would be more easy to select the device from the pool in the backup job.

for this... when creating new job look in Destination => Device and Media and on the right section, select the one of the 3 device insted of All Device for the job, by doing this you job will only use the device you have assigned for it and will run according to schedule.

hope this help in this case. try this and let us know.

[DrDebate]

Thank you pkh - very helpful!  I'm curious, if I enable that option, does that space automatically become available as media on the B2D device becomes overwritable?

[pkh]

I am not sure what you mean by space being available.  If a media is overwriteable, the space occupied by it can be re-used, i.e. overwritten, but it is not deleted from the volume.

[DrDebate]

What I want - ideally - is to have it use the three devices in the drive pool like a single device.  I want my backup jobs to fill up all three drives and then overwrite the oldest going forward.  My concern is that if I enable the setting you mentioned above, it will fill up a drive, move on the to the next, fill it up, move to the third and then once that device is full BE will be stuck.

[pkh]

To prevent this from happening, you must ensure that your OPP is set such that there would be overwriteable media before all 3 disk fills up.  It is no different from having just one disk.