We are trying to decide on the best way to configure disk storage for new DPM2012 R2 server. It has 2 x 300GB disks mirrored for OS, DPM and SQL. It has 12 x 3TB local disks for the storage pool. I've read that the maximum recommended disk size is 1.5TB. Does that mean we if we proceed with 3TB it is unsupported?

Why is the 1.5TB limit recommended?

Secondly what would people recommend for the RAID configuration. I was originally thinking one large array or RAID 5 or 10 but then read that the maximum DPM dev recommended LUN size is 17TB but it will work up to 80TB?

Why is there a 17TB limit? Considering we need at least 18TB of usable backup space what would you recommend?

Also is there any advantage in presenting multiple smaller LUNs to DPM as opposed to 1 single LUN. It seems DPM currently is unable to take advantage of tiered storage. e.g. use one RAID 10 LUN for performance and one RAID5 for capacity.

Thanks.

• Edited by Stu-NI 10 hours 24 minutes ago

I have since found out that you can choose which disk a protected data source uses by using a custom volume. The downside being that you have to manage the size manually.

Hi,

Q1) I've read that the maximum recommended disk size is 1.5TB. Does that mean we if we proceed with 3TB it is unsupported?  Why is the 1.5TB limit recommended?

A1) That may have been from old DPM documentation - we do not have any such limitation.

Q2)  Why is there a 17TB limit? Considering we need at least 18TB of usable backup space what would you recommend?

A2)  I believe this was a tested limit at one point, but larger sizes works and are supported.

Q3) Also is there any advantage in presenting multiple smaller LUNs to DPM as opposed to 1 single LUN. It seems DPM currently is unable to take advantage of tiered storage. e.g. use one RAID 10 LUN for performance and one RAID5 for capacity.

A3) Taking RAID out of the picture, a couple of advantages to using several smaller LUNS.

1) When a data source is protected, DPM will create two volumes, a replica volume and a recovery point volume. If there are more than one disks in the storage pool, DPM will create them on seperate disks for performance reasons.

2) If you ever want to migrate to new storage, it's easier to migrate smaller disks that larger ones.