Re: [DRBD-user] DRBD over ZFS - or the other way around?

Il 15-09-2017 17:12 David Bruzos ha scritto: Hi Danti, The behavior you are experiencing is normal. As I pointed out previously, I've been using this setup for many years and I've seen the same thing. You will encounter that when the filesystem is written on the DRBD device without the use

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Hi Danti, The behavior you are experiencing is normal. As I pointed out previously, I've been using this setup for many years and I've seen the same thing. You will encounter that when the filesystem is written on the DRBD device without the use of a partition table. As a side note,

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Il 06-09-2017 16:22 David Bruzos ha scritto: I've used DRBD devices on top of ZFS zvols for years now and have been very satisfied with the performance and possibilities that that configuration allows for. I use DRBD 8.x on ZFS latest mainly on Xen hypervisors running a mix a Linux and Windows

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Il 06-09-2017 16:03 Yannis Milios ha scritto: ...I mean by cloning it first, since snapshot does not appear as blockdev to the system but the clone does. Hi, this is incorrect: ZVOL snapshots surely can appear as regular block devices. You simply need to set the "snapdev=visible" property.

Re: [DRBD-user] DRBD over ZFS - or the other way around?

I've used DRBD devices on top of ZFS zvols for years now and have been very satisfied with the performance and possibilities that that configuration allows for. I use DRBD 8.x on ZFS latest mainly on Xen hypervisors running a mix a Linux and Windows VMs with both SSD and mechanical drives.

Re: [DRBD-user] DRBD over ZFS - or the other way around?

...I mean by cloning it first, since snapshot does not appear as blockdev to the system but the clone does. On Wed, Sep 6, 2017 at 2:58 PM, Yannis Milios wrote: > Even in that case I would prefer to assemble a new DRBD device ontop of > the ZVOL snapshot and then mount

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Even in that case I would prefer to assemble a new DRBD device ontop of the ZVOL snapshot and then mount the DRBD device instead :) On Wed, Sep 6, 2017 at 2:56 PM, Gionatan Danti wrote: > On 06/09/2017 15:31, Yannis Milios wrote: > >> If your topology is like the following:

Re: [DRBD-user] DRBD over ZFS - or the other way around?

On 06/09/2017 15:31, Yannis Milios wrote: If your topology is like the following: HDD -> ZFS (ZVOL) -> DRBD -> XFS then I believe it should make sense to always mount at the DRBD level and not at the ZVOL level which happens to be the underlying blockdev for DRBD. Sure! Directly mounting the

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Hi, On 06/09/2017 13:28, Jan Schermer wrote: Not sure you can mount snapshot (I always create a clone). the only difference is that snapshots are read-only, while clones are read-write. This is why I used the "-o ro,norecovery" option while mounting XFS. However I never saw anything

Re: [DRBD-user] DRBD over ZFS - or the other way around?

If your topology is like the following: HDD -> ZFS (ZVOL) -> DRBD -> XFS then I believe it should make sense to always mount at the DRBD level and not at the ZVOL level which happens to be the underlying blockdev for DRBD. On Wed, Sep 6, 2017 at 12:28 PM, Jan Schermer wrote:

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Not sure you can mount snapshot (I always create a clone). However I never saw anything about “drbd” filesystem - what distribution is this? Apparently it tries to be too clever… Try creating a clone and mounting it instead, it’s safer anyway (saw bug in issue tracker that ZFS panics if you try

Re: [DRBD-user] DRBD over ZFS - or the other way around?

On 19/08/2017 10:24, Yannis Milios wrote: Option (b) seems more suitable for a 2 node drbd8 cluster in a primary/secondary setup. Haven't tried it so I cannot tell if there are any clurpits. My only concern in such setup would be if drbd corrupts silently the data on the lower level and zfs is

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Hello, Personally I'm using option (a) on a 3 node proxmox cluster and drbd9. Replica count per VM is 2 and all 3 nodes act as both drbd control volumes and satellite nodes.I can live migrate VM over all 3 nodes without issues. Snapshots are also possible via drbdmanage + zfs snapshot + clones

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Il 18-08-2017 17:22 Veit Wahlich ha scritto: Yes, I regard qemu -> DRBD -> volume management [-> RAID] -> disk the most recommendable solution for this scenario. I personally go with LVM thinp for volume management, but ZVOLs should do the trick, too. With named ressources (named after VMs)

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Il 18-08-2017 17:09 Yannis Milios ha scritto: Personally I'm using option (a) on a 3 node proxmox cluster and drbd9. Replica count per VM is 2 and all 3 nodes act as both drbd control volumes and satellite nodes.I can live migrate VM between all nodes and snapshot them by using drbdmanage

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Am Freitag, den 18.08.2017, 15:46 +0200 schrieb Gionatan Danti: > Il 18-08-2017 14:40 Veit Wahlich ha scritto: > > VM live migration requires primary/primary configuration of the DRBD > > ressource accessed by the VM, but only during migration. The ressource > > can be reconfigured for

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Hello, Personally I'm using option (a) on a 3 node proxmox cluster and drbd9. Replica count per VM is 2 and all 3 nodes act as both drbd control volumes and satellite nodes.I can live migrate VM between all nodes and snapshot them by using drbdmanage utility (which is using zfs snapshot+clones).

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Il 18-08-2017 14:40 Veit Wahlich ha scritto: To clarify: Am Freitag, den 18.08.2017, 14:34 +0200 schrieb Veit Wahlich: hosts simultaniously, enables VM live migration and your hosts may even VM live migration requires primary/primary configuration of the DRBD ressource accessed by the VM,

Re: [DRBD-user] DRBD over ZFS - or the other way around?

To clarify: Am Freitag, den 18.08.2017, 14:34 +0200 schrieb Veit Wahlich: > hosts simultaniously, enables VM live migration and your hosts may even VM live migration requires primary/primary configuration of the DRBD ressource accessed by the VM, but only during migration. The ressource can be

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Hi, Am Freitag, den 18.08.2017, 14:16 +0200 schrieb Gionatan Danti: > Hi, I plan to use a primary/secondary setup, with manual failover. > In other words, split brain should not be possible at all. > > Thanks. having one DRBD ressource per VM also allows you to run VMs on both hosts

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Il 18-08-2017 12:58 Julien Escario ha scritto: If you design with a signle big ressource, a simple split brain and you're screwed. Julien Hi, I plan to use a primary/secondary setup, with manual failover. In other words, split brain should not be possible at all. Thanks. -- Danti Gionatan

Re: [DRBD-user] DRBD over ZFS - or the other way around?

Le 17/08/2017 à 16:48, Gionatan Danti a écrit : > Hi list, > I am discussing how to have a replicated ZFS setup on the ZoL mailing list, > and > DRBD is obviously on the radar ;) > > It seems that three possibilities exist: > > a) DRBD over ZVOLs (with one DRBD resource per ZVOL); > b) ZFS over

[DRBD-user] DRBD over ZFS - or the other way around?

Hi list, I am discussing how to have a replicated ZFS setup on the ZoL mailing list, and DRBD is obviously on the radar ;) It seems that three possibilities exist: a) DRBD over ZVOLs (with one DRBD resource per ZVOL); b) ZFS over DRBD over the RAW disks (with DRBD resource per disk); c) ZFS