What about the Samsung 845DC Pro SSD's? These have fantastic enterprise performance characteristics.
http://www.thessdreview.com/our-reviews/samsung-845dc-pro-review-800gb-class-leading-speed-endurance/ Kind regards Kevin On 28 February 2015 at 15:32, Philippe Schwarz <p...@schwarz-fr.net> 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 > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >
_______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
