ZFS stalled after some mirror disks were lost

[Ben RUBSON]

> On 03 Oct 2017, at 08:12, Andriy Gapon <avg at FreeBSD.org> wrote:
> 
> On 02/10/2017 21:12, Ben RUBSON wrote:
>> A sustained read throughput of 180 MB/s, 45 MB/s on each iscsi disk
>> according to "zpool iostat", nothing on local disks (strange but I
>> noticed that IOs always prefer iscsi disks to local disks).
> 
> Are your local disks SSD or HDD?

HDD.

> Could it be that iSCSI disks appear to be faster than the local disks to the
> smart ZFS mirror code?

Or because their /dev/da<number> are greater then the local ones ?
(as they are attached after the local disks)
(my 2 cents...)
For sure we could have expected the local disks to be preferred,
or at least the load to be spread among all (local & iscsi) disks.

> Steve, what do you think?