Every once in a while, we hear of users with corruption in a file
system that sits on top of DRBD. That may be easy or tricky to
resolve. If you’re lucky, a simple fsck
will resolve
the corruption. If you’re not quite that lucky, you may have to
get out your backups.
But that’s typically not DRBD’s fault. Typically not at all, not
in the least bit. DRBD is a block device, and as such it has no
idea what rests on top of it. It has no concept of a filesystem,
let alone its integrity. That of course is true for any other
block device as well. If you have, say, RAID-1, and something
corrupts the file system on top of it, then of course that
corruption will be happily replicated across both component
devices. DRBD is no different, except that its component devices
are stored across distinct physical nodes.
And even if everything about your filesystem is
logically correct, there’s still the chance that a …
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