ZFS inresponsive.

[James R. Van Artsdalen]

Thomas Zander wrote:
> Same here, same setup. ZFS, GELI, USB.

It is not a good idea to use USB disks with ZFS.  It can cause pool loss.

Many (most?) USB enclosures use USB<->SATA chips that discard the
SYNC/FLUSH command to the disk.  As a result this opens a window of time
where disk writes might be reordered in a way that cause the ZFS
structures to become corrupted.  There's no problem in normal operation
but there may be a failure if there is a power loss.

The log entries in Fabian's note look like a USB SYNC/FLASH failure to
me - that USB enclosure should not be used with ZFS.

At one time there was talk of "deferred reallocation" in ZFS which would
deal with broken USB enclosures but I don't know if Sun ever got around
to this.