On Thu, Jun 02, 2016 at 12:12:35PM +0500, Eugene M. Zheganin wrote:> Hi. > > On 01.06.16 18:23, Slawa Olhovchenkov wrote: > > > > Only FS support changed data bypass FS layer is Files-11 ODS-2 level, > > may be hardware support required. > > > > Can you use ZFS mirror with one vdev local and other vdev by iSCSI? > > Every node using separate ZFS pool in this case. > If you mean that I should distribute the HAST one-disk device via iSCSI > and then use it as a half of zfs mirrored pool on each node, then I > should ask how the pool will decide which half is more recent - local or > iSCSI, after I will import it and the kernel will found that it's vdevs > differs a lot ? And why should I prefere this overcomplicated scheme > over the geom_mirror, which seems rather simple when comparing. Seems > like I can point HAST to /dev/mirror/whatever device, right ?I am suggesting next setup: node0: own pool zroot0: mirror-0: local_disk0 remote-iscsi_disk1/1 local_disk1: exported by iscsi as remote-iscsi_disk0/1 to node1 node1: own pool zroot1: mirror-0: local_disk0 remote-iscsi_disk0/1 local_disk1: exported by iscsi as remote-iscsi_disk1/1 to node0 No HAST. Disks synced by ZFS over iSCSI.
Hi. On 02.06.16 19:50, Slawa Olhovchenkov wrote:> I am suggesting next setup: > > node0: > own pool zroot0: mirror-0: local_disk0 > remote-iscsi_disk1/1 > local_disk1: exported by iscsi as remote-iscsi_disk0/1 to node1 > > node1: > own pool zroot1: mirror-0: local_disk0 > remote-iscsi_disk0/1 > local_disk1: exported by iscsi as remote-iscsi_disk1/1 to node0 > > > No HAST. > Disks synced by ZFS over iSCSI.But this way I will get two independent zfs pools (or I still didn't get it), one half of each will be stored on another machine. And I need something different - a continuously replicated disk resource, that would be available on both machines in case either will crash. Cluster filesystem would be fine, but as far as I know there's no such thing on FreeBSD, so I accept it will be unavailable on slave while mounted as read-write on the master. HAST looks like a thing thats fits my requirement, only that I wank it to be redundant inside each host too, and all the documentation shows examples without local redundancy. Thanks. Eugene.
Hi, On 02.06.16 19:50, Slawa Olhovchenkov wrote:> > I am suggesting next setup: > > node0: > own pool zroot0: mirror-0: local_disk0 > remote-iscsi_disk1/1 > local_disk1: exported by iscsi as remote-iscsi_disk0/1 to node1 > > node1: > own pool zroot1: mirror-0: local_disk0 > remote-iscsi_disk0/1 > local_disk1: exported by iscsi as remote-iscsi_disk1/1 to node0You message lead me to a though that I could use iSCSI to replicate the zfs pool from node1 to both iSCSI-provided disk on a node2 in a 4-way mirror, right ? Are there any obvious obstacles to this, that I don't see, considering the bandwith will be enough ? Thanks. Eugene.