[DRBD-user] how to restore lvm snapshot?

[d tbsky]

Robert Altnoeder <robert.altnoeder at linbit.com>
> For a cluster with nodes A, B, C, where A is the node where the snapshot
> is restored to the backend device, a possible process is:
> - on B, drbdadm disconnect resource
> - on B, drbdadm invalidate resource
> - on C, drbdadm disconenct resource
> - on C, drbdadm invalidate resource
> - on A, drbdadm detach resource
> - on A, restore the snapshot to the backend device WITHOUT modifying
> DRBD meta data
>   If the volume has external meta data, restore only the volume
> contents, but not the meta data volume
>   If the volume has internal meta data, make sure the restore modifies
> only the data region, but not the meta data region
> - on A, drbdadm attach resource
> - on B, drbdadm connect resource
> - on C, drbdadm connect resource
>
> B and C run a full-sync from A
>
> Another possible process that is much easier for restoring the backend
> device WITH DRBD meta data to a volume containing internal meta data is:
> - on all nodes, drbdadm down resource
> - on B, drbdadm create-md resource
> - on C, drbdadm create-md resource
> - on A, restore the snapshot to the backend device, including internal
> DRBD meta data contained in the snapshot
> - on all nodes, drbdadm up resource
>
> Note that you must recreate meta data with the correct parameters
> (commonly the same parameters that were used to create meta data on A)
>
> B and C run a full-sync from A

   thanks a lot for the advice. I will try to do some testing about
it. basically I still need to destroy secondary data and re-sync. I
was hoping maybe there is a tricky faster way, but it seems we need to
do the hard work to keep data safe.