Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Tue, Jul 10, 2012 at 06:59:36PM +0200, Jean-Baptiste wrote: > Hello, > > Today I was confronted with this problem : > > I've got a 2 nodes cluster. Both of them uses drbd resource to assume > failover. > The main drbd resource store all the data of an Oracle SGBD. > > To solve my problematic (frequently resize resources), I decided to move > the drbd metadatas from internal to external volume. > > The sub-layer used is LVM. > Here is how I was do this : > The starting point is missing. Have the peers been "Connected UpToDate/UpToDate" ? > 1. Create new logical volume to store meta-datas > 2. Unmount the resource to migrate > 3. Dump the meta-datas to plain file > 4. Shutdown the resource (drbdadm down <RES>) > 5. Modify the drbd.conf to use meta-disk external > 6. Restart drbd daemon uhm. there is no drbd "daemon" ... but anyways... > 7. Create md for the resource (drbdadm create-md <RES>) I don't see the step where you restore the previously dumped meta data? > 8. Startup resource So in 7. you told DRBD that it was a fresh "just created" instance, without any valid data. If by "startup resource" you mean "drbdadm up <resource>" (or adjust), it will connect to the peer, which *does* have valid meta data, so immediate full sync is started right here, from the peer to the node where you did "create-md". > 9. Doing drbdadm -- --overwrite-data-of-peer primary <RES> (from the > primary node) Well, of course you can promote a SyncTarget to Primary, as it has access to the peers data. But the "--overwrite-data-of-peer" is actually a "--force", and only relevant if DRBD otherwise would have refused to promote. Which in this case, it likely would not have, anyways. > 10. Let synchronize process ending Without noticing that it was not the expected direction. > 11. Done > > At this step everything is fine, my SGBD was restarted without any warning, > nothing seems to go wrong. > But ... I was lost 11 days of data in my SGBD. > > I'm disapointed, does anyone have an idea about this ? > At least to explain this. > > Thanks -- : Lars Ellenberg : LINBIT | Your Way to High Availability : DRBD/HA support and consulting http://www.linbit.com