HAST, zfs and local mirroring

[Freddie Cash]

On Tue, May 31, 2016 at 11:18 AM, Eugene M. Zheganin <emz at norma.perm.ru>
wrote:

> I wat to start using HAST, I have two nodes and a pair of disk on each
> node. So I want to use HASt in an environment where each HAST resource
> would be mirrored. What is the preferred approach if I want to use ZFS on
> an end-device to avoid exsessive fscking, and, in the same time, I want to
> have some redundancy on a block level ? I see two possibility: HAST on a
> zvol of a mirrored pool, and a ZFS on a hast. But recently I heard that
> nested zfs (like zfs on zvol) is clamed unsupported. Futhermore, I have zfs
> on a geli on a zvol, and this solution proved itself to be very affected to
> livelocking - when disk i/o on a such fs is above some treshold, system is
> locking, and the only way out is to reset it. Should I chose geom_mirror to
> provide a device for HAST and the build ZFS on it ?
>

​The generally recommend way to do this is to create a HAST resource out of
1 disk from each system, and then build the ZFS pool using the HAST
resources as the "disks".

That way, your ZFS pool is made up of 2 HAST devices in a mirror vdev.

And each of the two HAST devices uses one disk from each server (total of
four disks).
​


-- 
Freddie Cash
fjwcash at gmail.com