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

David Bruzos david.bruzos at jaxport.com
Fri Sep 15 17:12:34 CEST 2017

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

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, I've had some nasty stability issues with the DRBD version in the kernel (4.4/4.9 kernels) when running on ZFS, but DRBD 8.4.10 and ZFS seem to be running great.  I also run the storage as part of dom0, which many admins don't recommend, but generally it works alright.  The stability issues were typically rare and happened under high I/O loads and were DRBD related deadlock type crashes.  Again, those problems seem to be resolve in the latest DRBD 8 RELEASE.


David Bruzos (Systems Administrator)
Jacksonville Port Authority
2831 Talleyrand Ave.
Jacksonville, FL  32206
Cell: (904) 625-0969
Office: (904) 357-3069
Email: david.bruzos at jaxport.com

On Wed, Sep 06, 2017 at 03:56:35PM +0200, Gionatan Danti wrote:
> 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 DRBD-backing ZVOL would, at the bare 
> minumum, ruin the replication with the peer.
> I was speaking about mounting ZVOLs *snapshots* to access previous data 
> version.
> Regards.
> -- 
> Danti Gionatan
> Supporto Tecnico
> Assyoma S.r.l. - www.assyoma.it
> email: g.danti at assyoma.it - info at assyoma.it
> GPG public key ID: FF5F32A8
> _______________________________________________
> drbd-user mailing list
> drbd-user at lists.linbit.com
> http://lists.linbit.com/mailman/listinfo/drbd-user


Please note that under Florida's public records law (F.S. 668.6076), most 
written communications 
to or from the Jacksonville Port Authority are public records, available to 
the public and media 
upon request. Your email communications may therefore be subject to public 
disclosure. If you have 
received this email in error, please notify the sender by return email and 
delete immediately 
without forwarding to others.

More information about the drbd-user mailing list