AW: Resource types

Hi Frank,

> I'm also running FailSafe without any shared storage, so I'd 
> be interested
> in using DRBD. Would it work with an older version of DRBD? 
> If not, what
> kinds of changes are needed?

Since I'm a longtime user of drbd myself, I'm fiddling with failsafe drbd support myself.

The most obvious change needed in the drbd resource script is a change in drbdsetup syntax: you must use

drbdsetup $Device primary
drbdsetup $Device secondary

instead of the older 

drbdsetup $Device PRI
drbdsetup $Device SEC

Also, the exclusive check needs review, for example a check for status Unconfigured or completely missing drbd device must be put in.

There's one other change that would be great to have but where I don't yet see how to do it: Currently, failsafe is very conservative and only allows activating drbd if no nodes show Primary" status. Actually having drbd show primary on the node that wants to activate would be OK and is something that's quite likely to happen in real life.

While syncing is in progress, the sendig side automatically goes to "primary mode"; sensible: only on the sending side may you access the device before syncing is finished. you also get primary mode when starting just one node without the 2nd one available - overriding "wait for other node" sets the local device to primary mode. Unfortunately, this prevents failsafe from starting the device at all - the exclusive check finds that somewhere the device is primary and gives up.

Two ways around that: If the exclusive script has a way of knowing which node wants to claim a resource, this could be correctly evaluated. is there any way to get this information in the control script?

Another way: Changing the test to fail only if the remote side is in Primary mode should work. Failsafe on the secondary node won't start until drbd sync is finished. One big problem with this aproach: it leaves you open to problems when you have a node with drbd running and failsafe stopped/not loaded, so I'd be much happyer avoiding this.

Any hints apreciated,

Martin Bene