On Thu, Feb 27, 2020 at 6:01 PM Chris Adams <cma@cmadams.net> wrote:
How well does oVirt handle an EqualLogic SAN controller switchover
event?  IIRC that can result in a short iSCSI "pause" (can't remember
how long it takes) - I'm not sure what oVirt's threshold before VMs
(including the hosted engine) get paused for storage timeouts.

I've got a small setup where the active SAN controller's battery has
gone bad, so I need to switch to the other controller, and I'm trying to
figure out the impact - do I need to shut all VMs (including the engine)
down first, will they just briefly pause and then continue, etc.
--
Chris Adams <cma@cmadams.net>

Hi Chris,
see my considerations and my notes on configuration on EQL in the archives, related to APD (All Paths Down), where one of the scenarios was indeed event of switching controller:

https://lists.ovirt.org/archives/list/users@ovirt.org/message/2R2ITNSOC67YTJD2GR5M54LLUCDA7IB4/ 

I also pointed some considerations of what vSphere does for disk timeouts on Linux when installing VMware Tools.
Unfortunately no answer, but it was August last year, so perhaps now we can have a revamping on considerations/feedbacks ;-)

See also my further considerations and tests scenarios on October, with Francesco Romani and Strahil
https://lists.ovirt.org/archives/list/users@ovirt.org/thread/BQA7NFCNREU5FX7QGTYADUPBVBNB4HVK/
and
https://lists.ovirt.org/archives/list/users@ovirt.org/thread/4DPJR7HGNDC45BJQG7HGUNEL4NIPJ6DO/

No happiness....
And in my case I have external engine and not hosted enginem that in this case of planned maintenance on EQL could have worse effects.
Recently I configured EQL replication, used during a Datacenter planned maintenance activity

Gianluca