Hi, i do some test, to reproduce this problem. As you can see, only one drive (each drive in same PG) is much more utilize, then others, and there are some ops in queue on this slow osd. This test is getting heads from s3 objects, alphabetically sorted. This is strange. why this files is going in much part only from this triple osd's. checking what osd are in this pg. ceph pg map 7.35b osdmap e117008 pg 7.35b (7.35b) -> up [18,61,133] acting [18,61,133] On osd.61 { "num_ops": 13, "ops": [ { "description": "osd_sub_op(client.10376104.0:961532 7.35b 2b11a75b\/2013-03-06-13-8700.1-ocdn\/head\/\/7 [] v 117008'1370134 snapset=0=[]:[] snapc=0=[])", "received_at": "2013-03-06 13:59:18.448543", "age": "0.032431", "flag_point": "started"}, { "description": "osd_sub_op(client.10376110.0:972570 7.35b 2b11a75b\/2013-03-06-13-8700.1-ocdn\/head\/\/7 [] v 117008'1370135 snapset=0=[]:[] snapc=0=[])", "received_at": "2013-03-06 13:59:18.453829", "age": "0.027145", "flag_point": "started"}, { "description": "osd_sub_op(client.10376104.0:961534 7.35b 2b11a75b\/2013-03-06-13-8700.1-ocdn\/head\/\/7 [] v 117008'1370136 snapset=0=[]:[] snapc=0=[])", "received_at": "2013-03-06 13:59:18.454012", "age": "0.026962", "flag_point": "started"}, { "description": "osd_sub_op(client.10376107.0:952760 7.35b 2b11a75b\/2013-03-06-13-8700.1-ocdn\/head\/\/7 [] v 117008'1370137 snapset=0=[]:[] snapc=0=[])", "received_at": "2013-03-06 13:59:18.458980", "age": "0.021994", "flag_point": "started"}, { "description": "osd_sub_op(client.10376110.0:972572 7.35b 2b11a75b\/2013-03-06-13-8700.1-ocdn\/head\/\/7 [] v 117008'1370138 snapset=0=[]:[] snapc=0=[])", "received_at": "2013-03-06 13:59:18.459546", "age": "0.021428", "flag_point": "started"}, { "description": "osd_sub_op(client.10376110.0:972574 7.35b 2b11a75b\/2013-03-06-13-8700.1-ocdn\/head\/\/7 [] v 117008'1370139 snapset=0=[]:[] snapc=0=[])", "received_at": "2013-03-06 13:59:18.463680", "age": "0.017294", "flag_point": "started"}, { "description": "osd_sub_op(client.10376107.0:952762 7.35b 2b11a75b\/2013-03-06-13-8700.1-ocdn\/head\/\/7 [] v 117008'1370140 snapset=0=[]:[] snapc=0=[])", "received_at": "2013-03-06 13:59:18.464660", "age": "0.016314", "flag_point": "started"}, { "description": "osd_sub_op(client.10376104.0:961536 7.35b 2b11a75b\/2013-03-06-13-8700.1-ocdn\/head\/\/7 [] v 117008'1370141 snapset=0=[]:[] snapc=0=[])", "received_at": "2013-03-06 13:59:18.468076", "age": "0.012898", "flag_point": "started"}, { "description": "osd_sub_op(client.10376110.0:972576 7.35b 2b11a75b\/2013-03-06-13-8700.1-ocdn\/head\/\/7 [] v 117008'1370142 snapset=0=[]:[] snapc=0=[])", "received_at": "2013-03-06 13:59:18.468332", "age": "0.012642", "flag_point": "started"}, { "description": "osd_sub_op(client.10376107.0:952764 7.35b 2b11a75b\/2013-03-06-13-8700.1-ocdn\/head\/\/7 [] v 117008'1370143 snapset=0=[]:[] snapc=0=[])", "received_at": "2013-03-06 13:59:18.470480", "age": "0.010494", "flag_point": "started"}, { "description": "osd_sub_op(client.10376107.0:952766 7.35b 2b11a75b\/2013-03-06-13-8700.1-ocdn\/head\/\/7 [] v 117008'1370144 snapset=0=[]:[] snapc=0=[])", "received_at": "2013-03-06 13:59:18.475372", "age": "0.005602", "flag_point": "started"}, { "description": "osd_sub_op(client.10376104.0:961538 7.35b 2b11a75b\/2013-03-06-13-8700.1-ocdn\/head\/\/7 [] v 117008'1370145 snapset=0=[]:[] snapc=0=[])", "received_at": "2013-03-06 13:59:18.479391", "age": "0.001583", "flag_point": "started"}, { "description": "osd_sub_op(client.10376107.0:952768 7.35b 2b11a75b\/2013-03-06-13-8700.1-ocdn\/head\/\/7 [] v 117008'1370146 snapset=0=[]:[] snapc=0=[])", "received_at": "2013-03-06 13:59:18.480276", "age": "0.000698", "flag_point": "started"}]} On osd.18 { "num_ops": 9, "ops": [ { "description": "osd_op(client.10391092.0:718883 2013-03-06-13-8700.1-ocdn [append 0~299] 7.2b11a75b)", "received_at": "2013-03-06 13:57:52.929677", "age": "0.025480", "flag_point": "waiting for sub ops", "client_info": { "client": "client.10391092", "tid": 718883}}, { "description": "osd_op(client.10373691.0:956595 2013-03-06-13-8700.1-ocdn [append 0~299] 7.2b11a75b)", "received_at": "2013-03-06 13:57:52.934533", "age": "0.020624", "flag_point": "waiting for sub ops", "client_info": { "client": "client.10373691", "tid": 956595}}, { "description": "osd_op(client.10391092.0:718885 2013-03-06-13-8700.1-ocdn [append 0~299] 7.2b11a75b)", "received_at": "2013-03-06 13:57:52.937101", "age": "0.018056", "flag_point": "waiting for sub ops", "client_info": { "client": "client.10391092", "tid": 718885}}, { "description": "osd_op(client.10373691.0:956597 2013-03-06-13-8700.1-ocdn [append 0~299] 7.2b11a75b)", "received_at": "2013-03-06 13:57:52.940284", "age": "0.014873", "flag_point": "waiting for sub ops", "client_info": { "client": "client.10373691", "tid": 956597}}, { "description": "osd_op(client.10373691.0:956598 2013-03-06-13-8700.1-ocdn [append 0~275] 7.2b11a75b)", "received_at": "2013-03-06 13:57:52.941170", "age": "0.013987", "flag_point": "waiting for sub ops", "client_info": { "client": "client.10373691", "tid": 956598}}, { "description": "osd_op(client.10373691.0:956601 2013-03-06-13-8700.1-ocdn [append 0~299] 7.2b11a75b)", "received_at": "2013-03-06 13:57:52.946009", "age": "0.009148", "flag_point": "waiting for sub ops", "client_info": { "client": "client.10373691", "tid": 956601}}, { "description": "osd_op(client.10391092.0:718887 2013-03-06-13-8700.1-ocdn [append 0~299] 7.2b11a75b)", "received_at": "2013-03-06 13:57:52.950400", "age": "0.004757", "flag_point": "waiting for sub ops", "client_info": { "client": "client.10391092", "tid": 718887}}, { "description": "osd_op(client.10373691.0:956603 2013-03-06-13-8700.1-ocdn [append 0~275] 7.2b11a75b)", "received_at": "2013-03-06 13:57:52.951217", "age": "0.003940", "flag_point": "waiting for sub ops", "client_info": { "client": "client.10373691", "tid": 956603}}, { "description": "osd_op(client.10373691.0:956604 2013-03-06-13-8700.1-ocdn [append 0~299] 7.2b11a75b)", "received_at": "2013-03-06 13:57:52.951491", "age": "0.003666", "flag_point": "waiting for sub ops", "client_info": { "client": "client.10373691", "tid": 956604}}]} iostat of this osd drives in same time. osd.61 is master i think. osd.133 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sde 0.00 0.00 1.00 816.67 4.00 29925.50 73.21 0.24 0.28 6.67 0.27 0.19 15.33 osd.61 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sdk 0.00 60.33 0.67 685.33 2.67 27458.83 80.06 1.48 2.16 54.00 2.11 1.45 99.47 osd.18 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sdt 0.00 0.00 2.00 809.67 8.00 27608.00 68.05 0.19 0.23 12.00 0.20 0.14 11.33 Sort o files number of files with same date, but only a little probe of all. 57 21 Nov 2012 58 11 Dec 2012 59 02 Jan 2013 59 17 Feb 2013 64 16 Feb 2013 65 27 Nov 2012 66 14 Dec 2012 69 01 Mar 2013 71 07 Feb 2013 71 20 Dec 2012 71 30 Nov 2012 72 22 Nov 2012 74 23 Nov 2012 81 13 Dec 2012 88 01 Dec 2012 90 21 Feb 2013 113 16 Nov 2012 118 10 Feb 2013 120 13 Feb 2013 142 15 Feb 2013 158 19 Feb 2013 195 29 Nov 2012 200 14 Feb 2013 606 18 Feb 2013 766 20 Feb 2013 1347 05 Dec 2012 2439 09 Dec 2012 2603 08 Dec 2012 Other osd's have very small number of iops. Best Regards SS -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html