I always forget something darn it. There will be two hosts attached to this group. Both are 2970's, 12 cores, 32GB ram. They are currently attached to a 14 drive raid 5 group with 500gb 5400rpm sata drives and I am out of space.
This gets back to more questions? We are going to try to hook the MD1000 up with the eight 1tb drives and seven 750gb drives to the MD3000i, copy all the VD's to it. Export the 14 drive 500gb SATA drives disk group off the array and remove all the drives, Export the seven 1tb drives and seven 750gb drives disk group, then move all the drives from the MD1000 enclosure to the MD3000i enclosure and then import the group back into the MD3000i.
Think it will work? 🙂
I hope so, we are talking about TB's and TB's and TB's of data here. So much so? No way to do it within a reasonable amount of time with restores. Only block level transfers can handle this change. You say I could of just added the MD1000 and been done with it right? Well, as it turns out our backup to disk based backup vault is also out of space which is also serviced by an MD3000i so I am going to put the 500GB drives back in the MD1000 and attach it permanently to the dedicated backup server MD3000i san doubling it's storage capacity.
I believe that your method should work. Exporting the disks from the expansion enclosure and re-importing them to the original enclosure would be the safest approach.
On the whole, the issue that you are seeing seems to be linked specifically to the SATA disks being used. In general, performance improves with spindle count, but it falls as the number of disks involved in parity calculation increases. Also, when feasible, it is recommended to create separate disk groups for high activity LUNs so that activity on one set of LUNs will only impact the disk group they are part of and not all the disks. So 2 disk groups should have overall better performance than a single large one.
However, as we know, performance has so many variables that it is tough to determine the exact single cause of poor performance. As the array tuning whitepaper says, apply config, test, tweak!
Thanks for the help to both of you. I have decided to leave it on RAID5, 750gb drives are right on the edge of this for me. If the enclosure was all 1TB drives I'd use raid 6. At leats this gives me an additional 750gb of space. 🙂