Selecting a strategy for easy mirror failure recovery

Not open for further replies.


Oct 1, 2011
I'm new to FreeNAS.
I have a FreeNAS box running FreeNAS-8.0.1-RELEASE-amd64-Full_Install from a USB stick and 2 2TB Samsung F4 HD204UI disks I plan to setup as mirror.

My understanding is that when one of the drives will fail I will have to replace it with a drive with the same number of sectors or more. Also, there is no way to guarantee that two drives of the same model from the same batch will have the same number of sectors which means I will always need to replace a failed drive with a bigger drive.

I came across this article titled 'ZFS: do not give it all your HDD' which proposes a way to solve this issue by reserving a small amount of sectors from the disk when creating a pool, allowing a replacement drive with a different number of sectors from the original drive to be used in its place.

My question is does this article make sense? If it's so easy shouldn't everyone do so?
Should I stop worrying about finding a drive with the same number of sectors and just plan to buy a bigger drive?

I know I can buy a replacement drive upfront but the 'number of sectors' issue is still valid.

Not open for further replies.