(6) 2TB drives in RAIDZ - how full can I fill the array?

[shackrock]

I know on laptops/desktops, people recommend not filling your HDD more than 80-90% of its rated capacity, because the drive works harder/etc...

Is this a valid concern on a FreeNAS server of (6) WD Green 2TB HDD's? ZFS file system, latest FreeNAS OS, RAIDZ array. I keep it on 24/7.

Thanks for any insight.

 

[peterh]

It's a concern for all types of storage where files are written and deleted.

A filesystem might have control over where new files are allocated, but no filesystem can control which blocks are freed when files are deleted, thus storage becomes fragmented.
The more fragmented, the lower the performance. Some filesystems deals with these
problems better then other.

I'd say that for decent long-term performance no filesystem should be more the 80% used.
Note that zfs does not give the extra "root-space" that most unix filesystem reserves
exclusivly for use by root, thus making it even more importent to keep pooles from
beeing completley full.

Also note that it is the pool that should have some freespace. The individual filesystems
carved from a pool can have all their quota used at no ill effects ( as the free space
is taken from the pool itself).

 

[sunflashx]

I have 6 1.5 TB drives in a RAIDZ1, and I've had mine up to around 98% full with no obvious ill effect. It's only operating as a media server, so it doesn't have a very high load on it though. Right now I'm down to 88% and it's just the same as when it was almost full.