[pve-devel] Default cache mode for VM hard drives

[Dietmar Maurer]

> Sorry, but I cannot find an explaination there?
> 
> In short:
> 1) DATA from write buffer commits locally
> 2) DATA in write buffer changes (because write cache is enabled)
> 3) DATA from write buffer sends to another DRBD node
> And DRBD can't catch this until integrity-alg not enabled. When enabled - we get
> split brain for each occurrence for master-master or just secondary
> reconnection for master-slave mode.

So this is a DRBD bug? If DRBD requires O_DSYNC, it is incredible slow?