reinstalled ceph packages and now with memstore backend [osd objectstore =memstore] its giving 400Kbps .No idea where the problem is.
On Sun, Mar 1, 2015 at 12:30 AM, mad Engineer <[email protected]> wrote: > tried changing scheduler from deadline to noop also upgraded to Gaint and > btrfs filesystem,downgraded kernel to 3.16 from 3.16-3 not much difference > > dd if=/dev/zero of=hi bs=4k count=25000 oflag=direct > 25000+0 records in > 25000+0 records out > 102400000 bytes (102 MB) copied, 94.691 s, 1.1 MB/s > > Earlier on a vmware setup i was getting ~850 KBps and now even on physical > server with SSD drives its just over 1MBps.I doubt some serious > configuration issues. > > Tried iperf between 3 servers all are showing 9 Gbps,tried icmp with > different packet size ,no fragmentation. > > i also noticed that out of 9 osd 5 are 850 EVO and 4 are 840 EVO.I believe > this will not cause this much drop in performance. > > Thanks for any help > > > On Sat, Feb 28, 2015 at 6:49 PM, Alexandre DERUMIER <[email protected]> > wrote: > >> As optimisation, >> >> try to set ioscheduler to noop, >> >> and also enable rbd_cache=true. (It's really helping for for sequential >> writes) >> >> but your results seem quite low, 926kb/s with 4k, it's only 200io/s. >> >> check if you don't have any big network latencies, or mtu fragementation >> problem. >> >> Maybe also try to bench with fio, with more parallel jobs. >> >> >> >> >> ----- Mail original ----- >> De: "mad Engineer" <[email protected]> >> À: "Philippe Schwarz" <[email protected]> >> Cc: "ceph-users" <[email protected]> >> Envoyé: Samedi 28 Février 2015 13:06:59 >> Objet: Re: [ceph-users] Extreme slowness in SSD cluster with 3 nodes and >> 9 OSD with 3.16-3 kernel >> >> Thanks for the reply Philippe,we were using these disks in our NAS,now >> it looks like i am in big trouble :-( >> >> On Sat, Feb 28, 2015 at 5:02 PM, Philippe Schwarz <[email protected]> >> wrote: >> > -----BEGIN PGP SIGNED MESSAGE----- >> > Hash: SHA1 >> > >> > Le 28/02/2015 12:19, mad Engineer a écrit : >> >> Hello All, >> >> >> >> I am trying ceph-firefly 0.80.8 >> >> (69eaad7f8308f21573c604f121956e64679a52a7) with 9 OSD ,all Samsung >> >> SSD 850 EVO on 3 servers with 24 G RAM,16 cores @2.27 Ghz Ubuntu >> >> 14.04 LTS with 3.16-3 kernel.All are connected to 10G ports with >> >> maximum MTU.There are no extra disks for journaling and also there >> >> are no separate network for replication and data transfer.All 3 >> >> nodes are also hosting monitoring process.Operating system runs on >> >> SATA disk. >> >> >> >> When doing a sequential benchmark using "dd" on RBD, mounted on >> >> client as ext4 its taking 110s to write 100Mb data at an average >> >> speed of 926Kbps. >> >> >> >> time dd if=/dev/zero of=hello bs=4k count=25000 oflag=direct >> >> 25000+0 records in 25000+0 records out 102400000 bytes (102 MB) >> >> copied, 110.582 s, 926 kB/s >> >> >> >> real 1m50.585s user 0m0.106s sys 0m2.233s >> >> >> >> While doing this directly on ssd mount point shows: >> >> >> >> time dd if=/dev/zero of=hello bs=4k count=25000 oflag=direct >> >> 25000+0 records in 25000+0 records out 102400000 bytes (102 MB) >> >> copied, 1.38567 s, 73.9 MB/s >> >> >> >> OSDs are in XFS with these extra arguments : >> >> >> >> rw,noatime,inode64,logbsize=256k,delaylog,allocsize=4M >> >> >> >> ceph.conf >> >> >> >> [global] fsid = 7d889081-7826-439c-9fe5-d4e57480d9be >> >> mon_initial_members = ceph1, ceph2, ceph3 mon_host = >> >> 10.99.10.118,10.99.10.119,10.99.10.120 auth_cluster_required = >> >> cephx auth_service_required = cephx auth_client_required = cephx >> >> filestore_xattr_use_omap = true osd_pool_default_size = 2 >> >> osd_pool_default_min_size = 2 osd_pool_default_pg_num = 450 >> >> osd_pool_default_pgp_num = 450 max_open_files = 131072 >> >> >> >> [osd] osd_mkfs_type = xfs osd_op_threads = 8 osd_disk_threads = 4 >> >> osd_mount_options_xfs = >> >> "rw,noatime,inode64,logbsize=256k,delaylog,allocsize=4M" >> >> >> >> >> >> on our traditional storage with Full SAS disk, same "dd" completes >> >> in 16s with an average write speed of 6Mbps. >> >> >> >> Rados bench: >> >> >> >> rados bench -p rbd 10 write Maintaining 16 concurrent writes of >> >> 4194304 bytes for up to 10 seconds or 0 objects Object prefix: >> >> benchmark_data_ceph1_2977 sec Cur ops started finished avg MB/s >> >> cur MB/s last lat avg lat 0 0 0 0 >> >> 0 0 - 0 1 16 94 78 >> >> 311.821 312 0.041228 0.140132 2 16 192 176 >> >> 351.866 392 0.106294 0.175055 3 16 275 259 >> >> 345.216 332 0.076795 0.166036 4 16 302 286 >> >> 285.912 108 0.043888 0.196419 5 16 395 379 >> >> 303.11 372 0.126033 0.207488 6 16 501 485 >> >> 323.242 424 0.125972 0.194559 7 16 621 605 >> >> 345.621 480 0.194155 0.183123 8 16 730 714 >> >> 356.903 436 0.086678 0.176099 9 16 814 798 >> >> 354.572 336 0.081567 0.174786 10 16 832 >> >> 816 326.313 72 0.037431 0.182355 11 16 833 >> >> 817 297.013 4 0.533326 0.182784 Total time run: >> >> 11.489068 Total writes made: 833 Write size: >> >> 4194304 Bandwidth (MB/sec): 290.015 >> >> >> >> Stddev Bandwidth: 175.723 Max bandwidth (MB/sec): 480 Min >> >> bandwidth (MB/sec): 0 Average Latency: 0.220582 Stddev >> >> Latency: 0.343697 Max latency: 2.85104 Min >> >> latency: 0.035381 >> >> >> >> Our ultimate aim is to replace existing SAN with ceph,but for that >> >> it should meet minimum 8000 iops.Can any one help me with this,OSD >> >> are SSD,CPU has good clock speed,backend network is good but still >> >> we are not able to extract full capability of SSD disks. >> >> >> >> >> >> >> >> Thanks, >> > >> > Hi, i'm new to ceph so, don't consider my words as holy truth. >> > >> > It seems that Samsung 840 (so i assume 850) are crappy for ceph : >> > >> > MTBF : >> > >> http://lists.ceph.com/pipermail/ceph-users-ceph.com/2014-November/044258.html >> > Bandwidth >> > : >> http://lists.ceph.com/pipermail/ceph-users-ceph.com/2014-December/045247.html >> > >> > And according to a confirmed user of Ceph/ProxmoX, Samsung SSDs should >> > be avoided if possible in ceph storage. >> > >> > Apart from that, it seems there was an limitation in ceph for the use >> > of the complete bandwidth available in SSDs; but i think with less >> > than 1Mb/s you haven't hit this limit. >> > >> > I remind you that i'm not a ceph-guru (far from that, indeed), so feel >> > free to disagree; i'm on the way to improve my knowledge. >> > >> > Best regards. >> > >> > >> > >> > >> > -----BEGIN PGP SIGNATURE----- >> > Version: GnuPG v1 >> > >> > iEYEARECAAYFAlTxp0UACgkQlhqCFkbqHRb5+wCgrXCM3VsnVE6PCbbpOmQXCXbr >> > 8u0An2BUgZWismSK0PxbwVDOD5+/UWik >> > =0o0v >> > -----END PGP SIGNATURE----- >> _______________________________________________ >> ceph-users mailing list >> [email protected] >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> > >
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