Hello Si, Let me clear this up for you. If you were using traditional disk groups then when you have a failed disk the hot spare will take over for the failed disk. Once the disk is replaced then the hotspare will go back to being a hotspare again.  When using a Dynamic Disk Pool it will use the reserved space that you provide for the DDP. If in the event that the space provided is full then it will take space from the disk pool itself to do the rebuild. Once the failed drive has been replaced then if it used any space in the disk pool it will return the space. If the space in the pool is not enough to allow the rebuild to complete the rebuild can run as long as it has all the matching segments need to keep the pool up in a degraded state.  Please let us know if you have any other questions.
Hi, I have updated the firmware of our MD3620i array to allow us to create a DDP. I have 48 x 600GB SAS 10K HDs in the DDP which has given me usable capacity of 19.253TB and preservation capacity of 1,668.000 GB (3 Physical Disks). I then created 3 equally sized LUNs which uses up all of the disk pool space (about 6,572GB in size each). After I finished this the array started warning me that the DDP was full. Is this a problem? I don’t want to create LUNs and leave free space that I can’t use, although if we have disk failure(s) will I then encounter issues? I would think the preservation capacity of 3 physical disks is what it would use to rebuild onto, so can I go into production with this configuration? Screenshot here - [URL] I have created VMFS datastores on these LUNs and they are working fine. Any help appreciated. Thanks
MD3620i DDP Question