On Mon, Jan 23, 2017 at 6:51 PM, Claude Duropcher <claude.durocher@cptaq.gouv.qc.ca> wrote:

Simone, thanks for replying,

According to the documentation, global mode seems to be a superset of local mode. Does setting to local mode maintenance on all hosts in the cluster really bring any benefits?


No, not really: they are different and global is not superset of local.
global maintenance mode is needed if you need to do maintenance on the engine VM, no host will restart the engine VM. local maintenance mode is if you need to do maintenance or upgrade a single host.

 

  • global - All high-availability agents in the cluster are disabled from monitoring the state of the engine virtual machine. The global maintenance mode must be applied for any setup or upgrade operations that require the engine to be stopped, such as upgrading to a later version of oVirt.

  • local - The high-availability agent on the host issuing the command is disabled from monitoring the state of the engine virtual machine. The host is exempt from hosting the engine virtual machine while in local maintenance mode; if hosting the engine virtual machine when placed into this mode, the engine will be migrated to another host, provided there is a suitable contender. The local maintenance mode is recommended when applying system changes or updates to the host.

Le 2017-01-23 à 12:13, Simone Tiraboschi a écrit :


On Mon, Jan 23, 2017 at 4:20 PM, Claude Duropcher <claude.durocher@cptaq.gouv.qc.ca> wrote:
Hi,

We need to update/reboot the NFS server on wich the hosted engine is installed. This server also hosts a couple of extra storage domains (ISO, Export and a iScsi domain). I'm wondering if this procedure is complete for an oVirt 4.0 installation :

1-set the environment to global maintenance

2-set the extra domains to maintenance mode

3-shutdown the hosted engine

4-update/reboot the storage server

5-reboot the hosted engine

6-reactivate extra domains

7-disable global maintenance mode

I'm wondering what's happening after step 4 and how ovirt will react when the NFS storage disapear and come back.


ovirt-ha-agent will try to reconnect the shared storage if hosted-engine for all the time; depending on different factors, sanlock will fail updating the hosted-engine lease ans this can bring the watchdog to reboot the host.
Setting also local maintenance mode on the involved hosts is a good idea.

 
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