[OpenIndiana-discuss] zfs and usb drives

[Jim Klimov]

2012-05-31 6:14, Bob Friesenhahn wrote:
> On Tue, 29 May 2012, Jay Heyl wrote:
>>
>> One idea is to use the external USB drives I've collected to create a
>> separate pool for the non-critical data. I have four 2TB USB drives that
>> have been performing flawlessly connected to Windows systems for quite a
>> while. Any opinions on using them to set up another raidz pool? Is this a
>> reasonable idea or a really bad idea?
>
> I have been using USB drives in a mirror configuration for quite a few
> years with zfs. No problems have been encountered due to using zfs. The
> main thing I learned is to always export the pool before unplugging the
> USB cables because the pool won't come back up if the cables are plugged
> into different ports than before.
>
> Zfs scrub and resilver are obviously slower with USB drives.
>
> I have heard that one should always plug the drives directly into the
> computer rather than into a USB bridge device.

Also, somebody recently had an issue moving the drives between
an USB enclosure and direct connection to the controller in the
computer - reported sector sizes varied, and the pool couldn't
be imported. If the drives are going to be in their enclosures
forever (as i.e. WD warranty policy requires), this is not a
problem - except that the box might report different "native"
sector sizes than those really supported by disk hardware, and
you might need to try enforcing one or another ashift (9, 12).

HTH,
//Jim Klimov