ZFS resize disk vdev
andrew at modulus.org
Mon Dec 8 22:43:58 PST 2008
Bryan Alves wrote:
> I'm thinking about using a hardware raid array with ZFS, using a single disk
> vdev zpool. I want the ability to add/remove disks to an array, and I'm
> still unsure of the stability of zfs as a whole. I'm looking for an easy
> way to resize and manage disks that are greater than 2 terabytes.
> If I have a single block device, /dev/da0, on my system that is represented
> by a zfs disk vdev, and the size of this block device grows (because the
> underlying hardware raid expands), will zfs correctly expand? And will it
> correctly expand in place?
In theory, this works fine - I have never tried it myself. The only
other way to expand a zpool is by adding more vdevs: You cannot change
a vdev once it is created other than to take it from a single disk to a
Sun's ZFS best practice guide states that you should avoid a single disk
vdev because performance on the whole suffers and is worse than UFS.
I am going to publish some benchmark figures soon to back this up, based
on testing I did with a 16 disk hardware RAID6. ZFS was *alot* faster
when I gave it the disks in a RAIDZ2 vdev.
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