[ClusterLabs] OS Patching Process

[Dmitri Maziuk]

On 2016-11-22 10:35, Jason A Ramsey wrote:
> Can anyone recommend a bulletproof process for OS patching a pacemaker
> cluster that manages a drbd mirror (with LVM on top of the drbd and luns
> defined for an iscsi target cluster if that matters)? Any time I’ve
> tried to mess with the cluster, it seems like I manage to corrupt my
> drbd filesystem, and now that I have actual data on the thing, that’s
> kind of a scary proposition. Thanks in advance!

+1

I managed to clearly standby/unstandby mine a few times initially -- 
otherwise I wouldn't have put it in production -- but on the last 
several reboots DRBD filesystem just wouldn't unmount. Never corrupted 
anything but it's still a serious PITA. Especially with a couple of 
haresources pairs right next to it switching over perfectly every time.

Insult to injury, the RA start spewing "can't unmount, somebody's 
holding open" messages to the console at such rate that it is impossible 
to login and try lsof, fuser, or anything.

Dima