I've tried all around to find a good solution for my conundrum, without
much luck.
The point is, multipath works nice. Until a bigger disaster comes along,
e.g. san or datacenter failure. Of course like most big environments you
have a synchronous replica of your SAN. But you have to "do stuff" to
get Linux to take that new LUN and get back to work. A reboot, or san
rescans, forcibly removing disks and so forth. It's not very pretty.
So my question is, is there any way to get multipath to treat both the
active lun and it's passive replica (usually in readonly or offline
state) as one and the same disk? The goal being, if your SAN fails, you
merely have to activate your DR replica, and multipath would pick it up
and all's well (except for the 30 sec to a few mins of I/O hanging until
the DR was online). In essence, you'd have four paths to a LUN - 2 to
the active one, 2 to the passive one, which is a different LUN
technically speaking (different serials, WWNs, etc), but an identical
synchronous replica (identical data, identical state, identical PVID, etc).
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
