On Mon, Aug 16, 2021 at 07:07:41AM +0100, TJ wrote: > I've got a rather unique scenario and need to allow non-exclusive > read-only opening of the drbd device on the Secondary.
> Then I thought to use a device-mapper COW snapshot - so the underlying > drbd device is never changed but the snapshot can be mounted at > /srv/tftp and any local changes won't affect the Primary. > > Snapshot works great. Assuming DBRD (Secondary) <-> ... LV You of course can do a lvcreate --snapshot of LV, and access that snapshot (RW, or RO, does not matter), while still being able to attach DRBD to the "origin" LV. What I suspect happened is: you "kpartx"d the LV, and that kept the LV open, so DRBD would refuse to attach. What I suggest you do: take that snpshot below DRBD, kpartx and cryptsetup the snapshot (to find your .../boot/) but make sure to not open or kpartx the origin LV. Lars _______________________________________________ Star us on GITHUB: https://github.com/LINBIT drbd-user mailing list drbd-user@lists.linbit.com https://lists.linbit.com/mailman/listinfo/drbd-user