Question: I have 2x 1.5TB drives in a (two-way mirror storage pool). That pool recently hit 100% capacity meaning both drives had 0% space left.
I added 2x 4TB drives to the storage pool but Storage space doesn’t attempt to rebalance the disk utilization. After I added I now see:
My storage space pool : Physical drives1.5 TB HDD-1 : 100% used1.5 TB HDD-2 : 100% used4.0 TB HDD-3 : 0% used4.0 TB HDD-4 : 0% used
Seems that all future writes would now be concentrated on the newer drives. I was expecting Storage Space to get busy once it saw the new drives and begin rebalancing – but no such luck.
How can I rebalance the usage so that my read/writes are distributed roughly proportionately/equally across all drives in my storage pool?
FYI, this is on Windows Server 2012 R2 but it’s the same storage space as Windows 8.1
Answer: Resurrecting this old question with something that finally works in the upcoming Windows 10 and Windows Server 2016 OSes.
Microsoft have added a Optimize-StoragePool PowerShell command in Windows 10 and Windows Server 2016 that rebalances storage spaces for an entire pool.
It’s as easy as opening an Administrative PowerShell console and running Optimize-StoragePool -FriendlyName “TheNameOfYourStoragePool”
I blogged about it here.
Microsoft announced the feature just a few days ago as part of the new Storage Spaces Direct but it works just fine with normal Storage Spaces as well.