Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Wed, Dec 29, 2010 at 02:49:00PM -0700, Chris Worley wrote: > I really think drbd is being brain-dead here. That's very much possible. But see http://old.nabble.com/IET-1.4.20.2-hosting-vmfs-on-drbd-complains-about-concurrent-write-td29756710.html#a29767518 > Concurrent writes to > the same LBA aren't an issue... just do it! But then, why not "just don't do it", on your part? > Note the below is using a > primary/secondary setup on two raw drbd devices; no GFS anywhere. > > Let me use an example of two fio invocations as an example, sorry if > you don't know fio. > > The first is an example of what I'd normally use, when telling it I > want to run two threads per drive. > > fio --rw=write --bs=1m --rwmixread=0 --iodepth=64 > --output=/tmp/fio.out.txt --group_reporting --sync=0 --direct=1 > --randrepeat=0 --softrandommap=1 --ioengine=libaio --loops=10000 > --name=test0 --filename=/dev/drbd0 --numjobs=2 --size=16093304832 > --name=tet1 --filename=/dev/drbd1 --numjobs=2 --size=16093304832 > > In the above case, nearly immediately, the systems starts spewing > "Concurrent local write detected", and as block sizes decrease the > machine-check monitor will eventually do a soft lockup, and the > thumb/boot drive will all of sudden think it's disconnected then > reconnect as a different SD device (leaving the system dead). I suspect that the "system dead" may be a result of the logged message being "alert" level, also ending up on some serial console, which then disables interrupts too often for too long so some other part of the system "breaks". > If I change the above to assure no two threads write to the same offsets, as in: > > fio --rw=write --rwmixread=0 --bs=1m --runtime=600 --iodepth=64 > --output=/tmp/fio.out.txt --group_reporting --sync=0 --direct=1 > --randrepeat=0 --softrandommap=1 --ioengine=libaio --loops=10000 \ > --name=test0-0 --filename=/dev/drbd0 --offset=0 --numjobs=1 > --size=8046652416 \ > --name=test0-1 --filename=/dev/drbd0 --offset=8046652416 --numjobs=1 > --size=8046652416 \ > --name=test1-0 --filename=/dev/drbd1 --offset=0 --numjobs=1 > --size=8046652416 \ > --name=test1-1 --filename=/dev/drbd1 --offset=8046652416 --numjobs=1 > --size=8046652416 > > ... then I see no problems. > > Unix semantics has you covered. If your told to write the same LBA > twice, just write the thing, and don't kill the system. > > Thanks, > > Chris > On Tue, Dec 28, 2010 at 1:06 PM, Chris Worley <worleys at gmail.com> wrote: > > On Thu, Dec 23, 2010 at 10:48 AM, J. Ryan Earl <oss at jryanearl.us> wrote: > >> On Mon, Dec 20, 2010 at 2:06 PM, Chris Worley <worleys at gmail.com> wrote: > >>> > >>> I'm using RHEL5.5/2.6.18-194.3.1.el5 and IB/SDP. > >> > >> What version of DRBD are you using and what versions have you tried? > > > > 8.3.8-1, using the precompiled binary RPMs. I've not tried other > > revs. I have tried other configurations, all of which seem to > > lock-up; in one configuration, the drive devices not associated with > > DRBD get locked-up and the devices go offline. > > > > Thanks, > > > > Chris > > > _______________________________________________ > drbd-user mailing list > drbd-user at lists.linbit.com > http://lists.linbit.com/mailman/listinfo/drbd-user -- : Lars Ellenberg : LINBIT | Your Way to High Availability : DRBD/HA support and consulting http://www.linbit.com DRBD® and LINBIT® are registered trademarks of LINBIT, Austria. __ please don't Cc me, but send to list -- I'm subscribed