Am 15.05.2014 09:56, schrieb Josef Johansson: > > On 15/05/14 09:11, Stefan Priebe - Profihost AG wrote: >> Am 15.05.2014 00:26, schrieb Josef Johansson: >>> Hi, >>> >>> So, apparently tmpfs does not support non-root xattr due to a possible >>> DoS-vector. There's configuration set for enabling it as far as I can see. >>> >>> CONFIG_TMPFS=y >>> CONFIG_TMPFS_POSIX_ACL=y >>> CONFIG_TMPFS_XATTR=y >>> >>> Anyone know a way around it? Saw that there's a patch for enabling it, >>> but recompiling my kernel is out of reach right now ;) >> I would create an empty file in tmpfs and then format that file as a >> block device. > How do you mean exactly? Creating with dd and mounting with losetup? mount -t tmpfs -o size=4G /mnt /mnt dd if=/dev/zero of=/mnt/blockdev_a bs=1M count=4000 mkfs.xfs -f /mnt/blockdev_a mount /mnt/blockdev_a /ceph/osd.X Dann /mnt/blockdev_a als OSD device nutzen. > > Cheers, > Josef >>> Created the osd with following: >>> >>> root at osd1:/# dd seek=6G if=/dev/zero of=/dev/shm/test-osd/img bs=1 count=1 >>> root at osd1:/# losetup /dev/loop0 /dev/shm/test-osd/img >>> root at osd1:/# mkfs.xfs /dev/loop0 >>> root at osd1:/# ceph osd create >>> 50 >>> root at osd1:/# mkdir /var/lib/ceph/osd/ceph-50 >>> root at osd1:/# mount -t xfs /dev/loop0 /var/lib/ceph/osd/ceph-50 >>> root at osd1:/# ceph-osd --debug_ms 50 -i 50 --mkfs --mkkey >>> --osd-journal=/dev/sdc7 --mkjournal >>> 2014-05-15 00:20:29.796822 7f40063bb780 -1 journal FileJournal::_open: >>> aio not supported without directio; disabling aio >>> 2014-05-15 00:20:29.798583 7f40063bb780 -1 journal check: ondisk fsid >>> bc14ff30-e016-4e0d-9672-96262ee5f07e doesn't match expected >>> b3f5b98b-e024-4153-875d-5c758a6060eb, invalid (someone else's?) journal >>> 2014-05-15 00:20:29.802155 7f40063bb780 -1 journal FileJournal::_open: >>> aio not supported without directio; disabling aio >>> 2014-05-15 00:20:29.807237 7f40063bb780 -1 >>> filestore(/var/lib/ceph/osd/ceph-50) could not find >>> 23c2fcde/osd_superblock/0//-1 in index: (2) No such file or directory >>> 2014-05-15 00:20:29.809083 7f40063bb780 -1 created object store >>> /var/lib/ceph/osd/ceph-50 journal /dev/sdc7 for osd.50 fsid >>> c51a2683-55dc-4634-9d9d-f0fec9a6f389 >>> 2014-05-15 00:20:29.809121 7f40063bb780 -1 auth: error reading file: >>> /var/lib/ceph/osd/ceph-50/keyring: can't open >>> /var/lib/ceph/osd/ceph-50/keyring: (2) No such file or directory >>> 2014-05-15 00:20:29.809179 7f40063bb780 -1 created new key in keyring >>> /var/lib/ceph/osd/ceph-50/keyring >>> root at osd1:/# ceph-osd --debug_ms 50 -i 50 --mkfs --mkkey >>> --osd-journal=/dev/sdc7 --mkjournal >>> 2014-05-15 00:20:51.122716 7ff813ba4780 -1 journal FileJournal::_open: >>> aio not supported without directio; disabling aio >>> 2014-05-15 00:20:51.126275 7ff813ba4780 -1 journal FileJournal::_open: >>> aio not supported without directio; disabling aio >>> 2014-05-15 00:20:51.129532 7ff813ba4780 -1 provided osd id 50 != >>> superblock's -1 >>> 2014-05-15 00:20:51.129845 7ff813ba4780 -1 ** ERROR: error creating >>> empty object store in /var/lib/ceph/osd/ceph-50: (22) Invalid argument >>> >>> Cheers, >>> Josef >>> >>> Christian Balzer skrev 2014-05-14 14:33: >>>> Hello! >>>> >>>> On Wed, 14 May 2014 11:29:47 +0200 Josef Johansson wrote: >>>> >>>>> Hi Christian, >>>>> >>>>> I missed this thread, haven't been reading the list that well the last >>>>> weeks. >>>>> >>>>> You already know my setup, since we discussed it in an earlier thread. I >>>>> don't have a fast backing store, but I see the slow IOPS when doing >>>>> randwrite inside the VM, with rbd cache. Still running dumpling here >>>>> though. >>>>> >>>> Nods, I do recall that thread. >>>> >>>>> A thought struck me that I could test with a pool that consists of OSDs >>>>> that have tempfs-based disks, think I have a bit more latency than your >>>>> IPoIB but I've pushed 100k IOPS with the same network devices before. >>>>> This would verify if the problem is with the journal disks. I'll also >>>>> try to run the journal devices in tempfs as well, as it would test >>>>> purely Ceph itself. >>>>> >>>> That would be interesting indeed. >>>> Given what I've seen (with the journal at 20% utilization and the actual >>>> filestore ataround 5%) I'd expect Ceph to be the culprit. >>>> >>>>> I'll get back to you with the results, hopefully I'll manage to get them >>>>> done during this night. >>>>> >>>> Looking forward to that. ^^ >>>> >>>> >>>> Christian >>>>> Cheers, >>>>> Josef >>>>> >>>>> On 13/05/14 11:03, Christian Balzer wrote: >>>>>> I'm clearly talking to myself, but whatever. >>>>>> >>>>>> For Greg, I've played with all the pertinent journal and filestore >>>>>> options and TCP nodelay, no changes at all. >>>>>> >>>>>> Is there anybody on this ML who's running a Ceph cluster with a fast >>>>>> network and FAST filestore, so like me with a big HW cache in front of >>>>>> a RAID/JBODs or using SSDs for final storage? >>>>>> >>>>>> If so, what results do you get out of the fio statement below per OSD? >>>>>> In my case with 4 OSDs and 3200 IOPS that's about 800 IOPS per OSD, >>>>>> which is of course vastly faster than the normal indvidual HDDs could >>>>>> do. >>>>>> >>>>>> So I'm wondering if I'm hitting some inherent limitation of how fast a >>>>>> single OSD (as in the software) can handle IOPS, given that everything >>>>>> else has been ruled out from where I stand. >>>>>> >>>>>> This would also explain why none of the option changes or the use of >>>>>> RBD caching has any measurable effect in the test case below. >>>>>> As in, a slow OSD aka single HDD with journal on the same disk would >>>>>> clearly benefit from even the small 32MB standard RBD cache, while in >>>>>> my test case the only time the caching becomes noticeable is if I >>>>>> increase the cache size to something larger than the test data size. >>>>>> ^o^ >>>>>> >>>>>> On the other hand if people here regularly get thousands or tens of >>>>>> thousands IOPS per OSD with the appropriate HW I'm stumped. >>>>>> >>>>>> Christian >>>>>> >>>>>> On Fri, 9 May 2014 11:01:26 +0900 Christian Balzer wrote: >>>>>> >>>>>>> On Wed, 7 May 2014 22:13:53 -0700 Gregory Farnum wrote: >>>>>>> >>>>>>>> Oh, I didn't notice that. I bet you aren't getting the expected >>>>>>>> throughput on the RAID array with OSD access patterns, and that's >>>>>>>> applying back pressure on the journal. >>>>>>>> >>>>>>> In the a "picture" being worth a thousand words tradition, I give you >>>>>>> this iostat -x output taken during a fio run: >>>>>>> >>>>>>> avg-cpu: %user %nice %system %iowait %steal %idle >>>>>>> 50.82 0.00 19.43 0.17 0.00 29.58 >>>>>>> >>>>>>> Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s >>>>>>> avgrq-sz avgqu-sz await r_await w_await svctm %util >>>>>>> sda 0.00 51.50 0.00 1633.50 0.00 7460.00 >>>>>>> 9.13 0.18 0.11 0.00 0.11 0.01 1.40 sdb >>>>>>> 0.00 0.00 0.00 1240.50 0.00 5244.00 8.45 0.30 >>>>>>> 0.25 0.00 0.25 0.02 2.00 sdc 0.00 5.00 >>>>>>> 0.00 2468.50 0.00 13419.00 10.87 0.24 0.10 0.00 >>>>>>> 0.10 0.09 22.00 sdd 0.00 6.50 0.00 1913.00 >>>>>>> 0.00 10313.00 10.78 0.20 0.10 0.00 0.10 0.09 16.60 >>>>>>> >>>>>>> The %user CPU utilization is pretty much entirely the 2 OSD processes, >>>>>>> note the nearly complete absence of iowait. >>>>>>> >>>>>>> sda and sdb are the OSDs RAIDs, sdc and sdd are the journal SSDs. >>>>>>> Look at these numbers, the lack of queues, the low wait and service >>>>>>> times (this is in ms) plus overall utilization. >>>>>>> >>>>>>> The only conclusion I can draw from these numbers and the network >>>>>>> results below is that the latency happens within the OSD processes. >>>>>>> >>>>>>> Regards, >>>>>>> >>>>>>> Christian >>>>>>>> When I suggested other tests, I meant with and without Ceph. One >>>>>>>> particular one is OSD bench. That should be interesting to try at a >>>>>>>> variety of block sizes. You could also try runnin RADOS bench and >>>>>>>> smalliobench at a few different sizes. >>>>>>>> -Greg >>>>>>>> >>>>>>>> On Wednesday, May 7, 2014, Alexandre DERUMIER <aderumier at odiso.com> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> Hi Christian, >>>>>>>>> >>>>>>>>> Do you have tried without raid6, to have more osd ? >>>>>>>>> (how many disks do you have begin the raid6 ?) >>>>>>>>> >>>>>>>>> >>>>>>>>> Aslo, I known that direct ios can be quite slow with ceph, >>>>>>>>> >>>>>>>>> maybe can you try without --direct=1 >>>>>>>>> >>>>>>>>> and also enable rbd_cache >>>>>>>>> >>>>>>>>> ceph.conf >>>>>>>>> [client] >>>>>>>>> rbd cache = true >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> ----- Mail original ----- >>>>>>>>> >>>>>>>>> De: "Christian Balzer" <chibi at gol.com <javascript:;>> >>>>>>>>> ?: "Gregory Farnum" <greg at inktank.com <javascript:;>>, >>>>>>>>> ceph-users at lists.ceph.com <javascript:;> >>>>>>>>> Envoy?: Jeudi 8 Mai 2014 04:49:16 >>>>>>>>> Objet: Re: Slow IOPS on RBD compared to journal and >>>>>>>>> backing devices >>>>>>>>> >>>>>>>>> On Wed, 7 May 2014 18:37:48 -0700 Gregory Farnum wrote: >>>>>>>>> >>>>>>>>>> On Wed, May 7, 2014 at 5:57 PM, Christian Balzer >>>>>>>>>> <chibi at gol.com<javascript:;>> >>>>>>>>> wrote: >>>>>>>>>>> Hello, >>>>>>>>>>> >>>>>>>>>>> ceph 0.72 on Debian Jessie, 2 storage nodes with 2 OSDs each. The >>>>>>>>>>> journals are on (separate) DC 3700s, the actual OSDs are RAID6 >>>>>>>>>>> behind an Areca 1882 with 4GB of cache. >>>>>>>>>>> >>>>>>>>>>> Running this fio: >>>>>>>>>>> >>>>>>>>>>> fio --size=400m --ioengine=libaio --invalidate=1 --direct=1 >>>>>>>>>>> --numjobs=1 --rw=randwrite --name=fiojob --blocksize=4k >>>>>>>>>>> --iodepth=128 >>>>>>>>>>> >>>>>>>>>>> results in: >>>>>>>>>>> >>>>>>>>>>> 30k IOPS on the journal SSD (as expected) >>>>>>>>>>> 110k IOPS on the OSD (it fits neatly into the cache, no surprise >>>>>>>>>>> there) 3200 IOPS from a VM using userspace RBD >>>>>>>>>>> 2900 IOPS from a host kernelspace mounted RBD >>>>>>>>>>> >>>>>>>>>>> When running the fio from the VM RBD the utilization of the >>>>>>>>>>> journals is about 20% (2400 IOPS) and the OSDs are bored at 2% >>>>>>>>>>> (1500 IOPS after some obvious merging). >>>>>>>>>>> The OSD processes are quite busy, reading well over 200% on atop, >>>>>>>>>>> but the system is not CPU or otherwise resource starved at that >>>>>>>>>>> moment. >>>>>>>>>>> >>>>>>>>>>> Running multiple instances of this test from several VMs on >>>>>>>>>>> different hosts changes nothing, as in the aggregated IOPS for >>>>>>>>>>> the whole cluster will still be around 3200 IOPS. >>>>>>>>>>> >>>>>>>>>>> Now clearly RBD has to deal with latency here, but the network is >>>>>>>>>>> IPoIB with the associated low latency and the journal SSDs are >>>>>>>>>>> the (consistently) fasted ones around. >>>>>>>>>>> >>>>>>>>>>> I guess what I am wondering about is if this is normal and to be >>>>>>>>>>> expected or if not where all that potential performance got lost. >>>>>>>>>> Hmm, with 128 IOs at a time (I believe I'm reading that correctly?) >>>>>>>>> Yes, but going down to 32 doesn't change things one iota. >>>>>>>>> Also note the multiple instances I mention up there, so that would >>>>>>>>> be 256 IOs at a time, coming from different hosts over different >>>>>>>>> links and nothing changes. >>>>>>>>> >>>>>>>>>> that's about 40ms of latency per op (for userspace RBD), which >>>>>>>>>> seems awfully long. You should check what your client-side objecter >>>>>>>>>> settings are; it might be limiting you to fewer outstanding ops >>>>>>>>>> than that. >>>>>>>>> Googling for client-side objecter gives a few hits on ceph devel and >>>>>>>>> bugs and nothing at all as far as configuration options are >>>>>>>>> concerned. Care to enlighten me where one can find those? >>>>>>>>> >>>>>>>>> Also note the kernelspace (3.13 if it matters) speed, which is very >>>>>>>>> much in the same (junior league) ballpark. >>>>>>>>> >>>>>>>>>> If >>>>>>>>>> it's available to you, testing with Firefly or even master would be >>>>>>>>>> interesting ? there's some performance work that should reduce >>>>>>>>>> latencies. >>>>>>>>>> >>>>>>>>> Not an option, this is going into production next week. >>>>>>>>> >>>>>>>>>> But a well-tuned (or even default-tuned, I thought) Ceph cluster >>>>>>>>>> certainly doesn't require 40ms/op, so you should probably run a >>>>>>>>>> wider array of experiments to try and figure out where it's coming >>>>>>>>>> from. >>>>>>>>> I think we can rule out the network, NPtcp gives me: >>>>>>>>> --- >>>>>>>>> 56: 4096 bytes 1546 times --> 979.22 Mbps in 31.91 usec >>>>>>>>> --- >>>>>>>>> >>>>>>>>> For comparison at about 512KB it reaches maximum throughput and >>>>>>>>> still isn't that laggy: >>>>>>>>> --- >>>>>>>>> 98: 524288 bytes 121 times --> 9700.57 Mbps in 412.35 usec >>>>>>>>> --- >>>>>>>>> >>>>>>>>> So with the network performing as well as my lengthy experience with >>>>>>>>> IPoIB led me to believe, what else is there to look at? >>>>>>>>> The storage nodes perform just as expected, indicated by the local >>>>>>>>> fio tests. >>>>>>>>> >>>>>>>>> That pretty much leaves only Ceph/RBD to look at and I'm not really >>>>>>>>> sure what experiments I should run on that. ^o^ >>>>>>>>> >>>>>>>>> Regards, >>>>>>>>> >>>>>>>>> Christian >>>>>>>>> >>>>>>>>>> -Greg >>>>>>>>>> Software Engineer #42 @ http://inktank.com | http://ceph.com >>>>>>>>>> >>>>>>>>> -- >>>>>>>>> Christian Balzer Network/Systems Engineer >>>>>>>>> chibi at gol.com <javascript:;> Global OnLine Japan/Fusion >>>>>>>>> Communications http://www.gol.com/ >>>>>>>>> _______________________________________________ >>>>>>>>> ceph-users mailing list >>>>>>>>> ceph-users at lists.ceph.com <javascript:;> >>>>>>>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >>>>>>>>> >>>>> _______________________________________________ >>>>> ceph-users mailing list >>>>> ceph-users at lists.ceph.com >>>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >>> _______________________________________________ >>> ceph-users mailing list >>> ceph-users at lists.ceph.com >>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >
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