It seems pretty common to find customers install DRBD for the wrong reasons. There are many pros/cons to compare DRBD to replication, but I’ve managed to cut down my spiel I give to customers to these two points:
So if you are installing DRBD with the aim of purely “availability”, and are not worried about losing that last write on the crash to your master database that (hopefully) happens only once every few years, you may be using the wrong technology.
While the prized “1 minute failover” is possible in DRBD, it doesn’t really explain the full picture. The typical crash recovery process in DRBD is a lot longer:
Now, having said that: If you have an application that requires 100% consistency, then DRBD is one of your best choices on the mysql-market today.