Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Tuesday 26 October 2010 23:20:40 Lewis Donzis wrote: > We'd like to be able to make backups from our DRBD secondary by mounting > the underlying filesystems. After some searching, this appears to be a > relatively common discussion: running DRBD on top of LVM, making a > snapshow of the backing LV on the secondary, and mounting the snapshot LV. > As has been discussed, it's not perfect, but it should produce reasonable > results most of the time, at least no worse than if there had been a power > failure. > > So, I'm sorry if this is a silly question, but I can't seem to get this to > work. It appears that DRBD permanently prevents mounting the backing > device (or its snapshot) because "drbdadm create-md" function modifies the > filesystem so that it can no longer be mounted except via the /dev/drbdX > device. In particular, attempting to mount a snapshot, or detaching DRBD > from the backing device and attempting to mount the file system, or even > just attempting to mount the backing device after create-md has run, > results in: > > mount: unknown filesystem type 'drbd' > > I see that the general concensus is that "it should work fine", so it > seems like there must be some simple explanation. Fyi,we're using Ubuntu > 10.04 which loads DRBD version 8.3.7. > > Thanks for your assistance, > > lew > _______________________________________________ > drbd-user mailing list > drbd-user at lists.linbit.com > http://lists.linbit.com/mailman/listinfo/drbd-user You need to run LVM on top of DRBD for that. You can have LVM - DRBD - LVM, but the snapshotting should occur on the top LVM. B.