[DRBD-user] Dual-primary setup: disconnecting

Stephan Budach stephan.budach at jvm.de
Tue Mar 19 17:11:05 CET 2013

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

Am 18.03.13 20:05, schrieb Stephan Budach:
> Am 18.03.13 10:07, schrieb Lars Ellenberg:
>> On Sun, Mar 17, 2013 at 08:19:26AM +0100, Stephan Budach wrote:
>>> Hi all,
>>> I am running DRBD 8.4.3 in a dual-pri setup. DRBD interlink is
>>> through a 10 GbE Intel Cx520 link, which is piggy-backed between the
>>> two Supermicro boxes. I have configured two SCST iscsi targets from
>>> two DRBD volumes, which configured as multipathed targets on three
>> Don't.
>> Simply: Don't.
>> Multipath expects to talk via more than one path to *the same target*.
>> What your setup does it have multipath talk (via one path each) to
>> *two different targets*, that don't know of each other,
>> and happen to be able to present the same data most of the time.
>> As iSCSI is not just about READs and WRITEs, but, especially in a
>> clustered setup, about reservations and other management commands,
>> this CAN NOT WORK, and that is NOT drbd's fault.
>> So just don't.
>> Thank you.
>> 	Lars
> Hi Lars,
> okay, point taken, but what about the issue with drbd disconnecting 
> when both primary get under high load? Even without iSCSI access this 
> shouldn't happen, should it?
> Thanks,
> Stephan
Btw, LIO does support SCSI3 persistent reservations, so one could swap 
scst with LIO and build multipathed iSCSI targets with it, unless I am 
mistaken and have misread anything.


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.linbit.com/pipermail/drbd-user/attachments/20130319/1ef6914a/attachment.htm>

More information about the drbd-user mailing list