[DRBD-user] DRBD + LVM (lvm config disappears)

[Graham Wood]

> The specific thing about this however was that the lvm was created on
> /dev/drbd0, not /dev/sda3 (which is what /dev/drbd0 is mapped onto), so I am
> somewhat concerned about the data corruption problems this may cause with
> lvm accessing the underlying device (sda3) rather than the mapped device
> (drbd0).
I believe the problems I've had in the past were caused by this.  The  
best way to see if there is a problem is to set both to secondary (so  
that they are consistent & not being written to), and md5sum the  
device.  If they are different, then invalidate one of the copies and  
let it resync.

If you want to reduce your downtime, pick your prefered copy, and just  
invalidate the other one - I'd probably reboot it just to make sure.

LVM level corruption is unlikely (unless you've changed lv  
configuration), but data corruption is certainly possible/likely.

Graham