Using HDD's for ZFS: 'desktop' vs 'raid / enterprise' -edition drives?

Frederique Rijsdijk frederique at isafeelin.org
Fri Jan 2 13:49:53 UTC 2009


Hi freebsd-questions,

For personal use (photo/video storage), I'm looking into creating a huge
single ZFS (raidz) volume that will replace my current collection of
drives used as storage. I'm thinking 4*1TB drives in RAID5(z).

My question is regarding the flavour of drivers that one can choose
from: Desktop class drives, or the so called RAID/Enterprise class drives.

The difference between the two being the way such a drive handles the
bad-sector/block handling and remapping. I understand that Desktop class
drives do all this internally, and this is a process that can take up to
>60s (even minutes on some), and during this process the drive is 
unavailable to the controller. The RAID edition drives all appoach this
differently and alot faster, typically before 8 seconds.

How does ZFS handle this? Should I be looking for the RAID class drives
or can Desktop class drives be used here?

My worry is of course that such a drive (destkop class) will be marked
defective and thrown out of the raid volume if a remapping of bad
sectors occurs and the drive will be unresponsive to the controller/ZFS
for > 8 seconds.

Some drives can be configured in this area, but not all, and there's
quite a price difference in the two, the desktop class being up to 50%
cheaper in some cases..

Anybody that can shed some light on this?


Thanks,

-- Frederique






More information about the freebsd-questions mailing list