Expanding pool with disks from different shelves - performance issues?

Question

I'm working on a VNX 5300 that had some LUN's created in sets of 6 disks. These LUN's are no longer being used and the goal is to reallocate the disks to an existing RAID6 (6+2) pool. The freed up disks are spread out amongst the various shelves. For example, I have a set of 6 disks in Bus 1 Enclosure 0, Disk 0-5, and another set in Bus 1 Enclosure 3, Disk 1-6.

Are there going to be any notable performance issues if I expand the RAID6 pool by 8 disks that are not sequential and are spread over two disk shelves; or is the performance difference negligible? Would the data rebalancing process end up reallocating all the data across the physical disks for optimal performance? System is at FLARE 5.32.000.5.201.

dynamox · Accepted Answer

my NL-SAS drives are spread all over the place i can't tell the difference, it's NL-SAS so i don't expect a lot from this tier anyway. Best practice recommends to expand specific tier by the same number of drives it was originally created with. Yes, with flare 32 it will rebalance within Capacity tier. If you don't have FAST license this rebalance will happen only when you add the new drives.

tickermcse76 · Answer

These disks are NL-SAS as well and we've expanding by blocks of 8.  Thanks for the input.

kelleg · Answer

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glen

Anonymous User · Answer

I hope we are not creating RAID Groups, it is Pool. Pool is meant to have heterogeneous drives & RAID types. There wont be any performance issue. If you compare RAID Groups & Pool, you will obviously be able to measure the performance.

tickermcse76 · Answer

Yes this is just one large block storage pool; thanks.

VNX

Expanding pool with disks from different shelves - performance issues?

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