drbd-user May 2010 archive
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drbd-user: Re: [DRBD-user] Critical Fail :: bio would need to, b

Re: [DRBD-user] Critical Fail :: bio would need to, but cannot, be split :: No Xen

From: Mike Peachey <mike.peachey_at_nospam>
Date: Wed May 19 2010 - 08:34:14 GMT
To: Florian Haas <florian.haas@linbit.com>, drbd-user@lists.linbit.com

Florian Haas wrote:
> Mike, is there any feedback from the LVM guys on this matter? Have you
> polled them like I suggested on IRC?

Indeed.

> 15:28:49 <@agk> there are several related problems with max segments, including that it can be changed *after* the stack device stack is built up, and the
> upper layers won't know
> 15:32:03 <@agk> and there can be a problem to do with merge_bvec_fn
> 15:49:20 -!- kennepede [~pkennedy@redhat/jboss/kennepede] has quit [Remote host closed the connection]
> 15:52:52 <@agk> drbd has blk_queue_max_segments(q, max_segments ? max_segments : BLK_MAX_SEGMENTS);
> 15:53:23 <@agk> and also has
> 15:53:23 <@agk> if (bio->bi_vcnt != 1 || bio->bi_idx != 0 || bio->bi_size > DRBD_MAX_SEGMENT_SIZE) {
> 15:53:27 <@agk> /* rather error out here than BUG in bio_split */
> 15:54:07 <@agk> blkdev.h:IBLK_MAX_SEGMENTSI= 128,
> 15:54:47 <@agk> so some other code path must be relied upon to limit that to 1 before hitting the error you're getting
> 15:56:24 <@agk> definitely one for the drbd folk to debug first
>

-- Kind Regards, __________________________________________________ Mike Peachey, IT Systems Administrator Tel: +44 114 281 2655 Fax: +44 114 281 2951 Jennic Ltd, Furnival Street, Sheffield, S1 4QT, UK Comp Reg No: 3191371 - Registered In England http://www.jennic.com __________________________________________________ _______________________________________________ drbd-user mailing list drbd-user@lists.linbit.com http://lists.linbit.com/mailman/listinfo/drbd-user