I think everyone understands that it’s not possible to select a specified disk from the DPM storage pool as a target disk for a specific protection group, however we can always move data between disks as far as the same DPM server has access to both disks.
Lets suppose we have ten protection groups and ten disks, and we moved data of a particular protection group (let’s say that data was written in disk one and disk two) to a particular disk (let’s say disk three).
Does that mean that DPM will never ever use disk one and disk two for this particular protection group and will always use disk three or can it use disk three along with any other disks, except for disk one or disk two?
To try to contextualize this a bit better, let’s imagine that we’ve attached a new disk to the storage pool of DPM and we want the data of a particular protection group to end up there.
Maybe an odd request however some customer ask for it…
The trick here will be to use custom volumes instead of the DPM storage pool. So basically after we add the new disk we can just create a custom volume on it – we just need to make sure we convert it to dynamic before anything else just in case we need to stretch it or shrink it…
DPM cannot allocate space on any disks not in the DPM storage pool, so using custom volume on disks outside the storage pool will ensure that the disk is only used for the data sources you configured (or migrated) to use that disk.
After this we need to migrate the data sources to this recently created custom volume. Just a quick note which may be handy – we will need two custom volumes per data source, one for replica and the other for recovery point.
If you check this other post you can see an example of migrating a data source from DPM storage pool to custom volumes…