Ilya, I think i spoke too soon in my last message. I've not given it more load (running 8 concurrent dds with bs=4M) and about a minute or so after starting i've seen problems in dmesg output. I am attaching kern.log file for you reference.
Please check starting with the following line: Nov 29 12:07:38 arh-ibstorage1-ib kernel: [ 3831.906510] . This is when I've started the concurrent 8 dds. The command that caused this is: time dd if=/dev/zero of=4G00 bs=4M count=5K oflag=direct & time dd if=/dev/zero of=4G11 bs=4M count=5K oflag=direct &time dd if=/dev/zero of=4G22 bs=4M count=5K oflag=direct &time dd if=/dev/zero of=4G33 bs=4M count=5K oflag=direct & time dd if=/dev/zero of=4G44 bs=4M count=5K oflag=direct & time dd if=/dev/zero of=4G55 bs=4M count=5K oflag=direct &time dd if=/dev/zero of=4G66 bs=4M count=5K oflag=direct &time dd if=/dev/zero of=4G77 bs=4M count=5K oflag=direct & I've ran the same test about 10 times but with only 4 concurrent dds and that didn't cause the issue. Should I try the 3.18 kernel again to see if 8dds produce similar output? Andrei ----- Original Message ----- > From: "Ilya Dryomov" <ilya.dryo...@inktank.com> > To: "Andrei Mikhailovsky" <and...@arhont.com> > Cc: "ceph-users" <ceph-users@lists.ceph.com> > Sent: Saturday, 29 November, 2014 10:40:48 AM > Subject: Re: [ceph-users] Giant + nfs over cephfs hang tasks > On Sat, Nov 29, 2014 at 2:33 AM, Andrei Mikhailovsky > <and...@arhont.com> wrote: > > Ilya, > > > > not sure if dmesg output in the previous is related to the cephfs, > > but from > > what I can see it looks good with your kernel. I would have seen > > hang tasks > > by now, but not anymore. I've ran a bunch of concurrent dd tests > > and also > > the file touch tests and there are no more delays. > > > > So, it looks like you have nailed the bug! > Great, good to have another data point. > > > > Do you plan to backport the fix to the 3.16 or 3.17 branches? > That's the tricky part. Can you try > http://gitbuilder.ceph.com/kernel-deb-precise-x86_64-basic/ref/for-andrei-1/linux-image-3.17.4-ceph-00638-g0f25ebb_3.17.4-ceph-00638-g0f25ebb-1_amd64.deb > ? > Thanks, > Ilya
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