Blimey Laurence - you're really pushing the boat out on this one! On Thu, 3 Jan 2019 at 22:40, Laurence Oberman <loberman@xxxxxxxxxx> wrote: > > On Thu, 2019-01-03 at 22:24 +0000, Sitsofe Wheeler wrote: > > Hi, > > > > On Thu, 3 Jan 2019 at 20:47, Laurence Oberman <loberman@xxxxxxxxxx> > > wrote: > > > > > > Hello > > > > > > I put the 860 in an enclosure (MSA50) driven by a SAS HBA > > > (megaraid)sas) > > > > > > The backplane is SAS or SATA > > > > > > /dev/sg2 0 0 49 0 0 /dev/sdb ATA Samsung SSD 860 1B6Q > > > > > > Running the same fio test of yours on latest RHEL7 and 4.20.0+-1 I > > > am > > > unable to reproduce this issue of yours after multiple test runs. > > > > > > Tests all run to completion with no errors on RHEL7 and upstream > > > kernels. > > > > > > I have no way to test at the moment with a direct motherboard > > > connection to a SATA port so if this is a host side issue with sata > > > (ATA) I would not see it. > > > > > > What this likely means is that the drive itself seems to be well > > > behaved here and the power or cable issue I alluded to earlier may > > > be > > > worth looking into for you or possibly the host ATA interface. > > > > > > RHEL7 kernel > > > 3.10.0-862.11.1.el7.x86_64 > > > > Thanks for going the extra mile on this Laurence - it does sound like > > whatever issue I'm seeing with the 860 EVO is local to my box. It's > > curious that others are seeing something similar (e.g. > > https://github.com/zfsonlinux/zfs/issues/4873#issuecomment-449798356 > > ) > > but maybe they're in the same boat as me. > > > > > test: (g=0): rw=randread, bs=(R) 32.0KiB-32.0KiB, (W) 32.0KiB- > > > 32.0KiB, > > > (T) 32.0KiB-32.0KiB, ioengine=libaio, iodepth=32 > > > fio-3.3-38-gf5ec8 > > > Starting 1 process > > > Jobs: 1 (f=1): [r(1)][100.0%][r=120MiB/s,w=0KiB/s][r=3839,w=0 > > > IOPS][eta > > > 00m:00s] > > > test: (groupid=0, jobs=1): err= 0: pid=3974: Thu Jan 3 15:14:10 > > > 2019 > > > read: IOPS=3827, BW=120MiB/s (125MB/s)(70.1GiB/600009msec) > > > slat (usec): min=7, max=374, avg=23.78, stdev= 6.09 > > > clat (usec): min=449, max=509311, avg=8330.29, stdev=2060.29 > > > lat (usec): min=514, max=509331, avg=8355.00, stdev=2060.29 > > > clat percentiles (usec): > > > | 1.00th=[ 5342], 5.00th=[ 7767], 10.00th=[ 8225], 20.00th=[ > > > 8291], > > > | 30.00th=[ 8291], 40.00th=[ 8291], 50.00th=[ 8291], 60.00th=[ > > > 8291], > > > | 70.00th=[ 8356], 80.00th=[ 8356], 90.00th=[ 8455], 95.00th=[ > > > 8848], > > > | 99.00th=[11600], 99.50th=[13042], 99.90th=[16581], > > > 99.95th=[17695], > > > | 99.99th=[19006] > > > bw ( KiB/s): min=50560, max=124472, per=99.94%, avg=122409.89, > > > stdev=2592.08, samples=1200 > > > iops : min= 1580, max= 3889, avg=3825.22, stdev=81.01, > > > samples=1200 > > > lat (usec) : 500=0.01%, 750=0.03%, 1000=0.02% > > > lat (msec) : 2=0.08%, 4=0.32%, 10=97.20%, 20=2.34%, 50=0.01% > > > lat (msec) : 750=0.01% > > > cpu : usr=4.76%, sys=12.81%, ctx=2113947, majf=0, > > > minf=14437 > > > IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, > > > 32=100.0%, > > > > =64=0.0% > > > > > > submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, > > > 64=0.0%, > > > > =64=0.0% > > > > > > complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.1%, > > > 64=0.0%, > > > > =64=0.0% > > > > > > issued rwts: total=2296574,0,0,0 short=0,0,0,0 dropped=0,0,0,0 > > > latency : target=0, window=0, percentile=100.00%, depth=32 > > > > > > Run status group 0 (all jobs): > > > READ: bw=120MiB/s (125MB/s), 120MiB/s-120MiB/s (125MB/s- > > > 125MB/s), > > > io=70.1GiB (75.3GB), run=600009-600009msecmodinfo ata > > > > > > Disk stats (read/write): > > > sdb: ios=2295763/0, merge=0/0, ticks=18786069/0, > > > in_queue=18784356, > > > util=100.00% > > > > For what it's worth, the speeds I see with NCQ off on the Samsung 860 > > EVO are not far off what you're reporting (but are much lower than > > those I see on the MX500 in the same machine). I suppose it could > > just > > be the MX500 is simply a better performing SSD for the specific > > workload I have been testing... > > > > -- > > Sitsofe | http://sucs.org/~sits/ > > Hello Sitsofe > > I am going to try tomorrow on a motherboard direct connection. > My testing was with no flags to libata, but of course ATA is hidden > host wise in my test as I am going via megaraid_sas to the MSA50 shelf. > > Are you using 32k blocks on the MX500 as well, is that 12gbit or 6gbit > SAS (The MX500) > Was it the same read tests via fio. Yes I'm using 32k blocks on the MX500 as well: # Samsung 860 EVO (with NCQ disabled) # fio --readonly --name=test --rw=randread --filename \ $(readlink -f /dev/disk/by-id/ata-Samsung_SSD_860_EVO_500GB_XXXXXXXXXXXXXXX) \ --bs=32k --ioengine=libaio --iodepth=32 --direct=1 --runtime=60s \ --time_based=1 test: (g=0): rw=randread, bs=(R) 32.0KiB-32.0KiB, (W) 32.0KiB-32.0KiB, (T) 32.0KiB-32.0KiB, ioengine=libaio, iodepth=32 fio-3.1 Starting 1 process Jobs: 1 (f=1): [r(1)][100.0%][r=107MiB/s,w=0KiB/s][r=3410,w=0 IOPS][eta 00m:00s] test: (groupid=0, jobs=1): err= 0: pid=3671: Fri Jan 4 07:21:20 2019 read: IOPS=3098, BW=96.8MiB/s (102MB/s)(5811MiB/60010msec) slat (usec): min=9, max=1398, avg=47.83, stdev=12.78 clat (usec): min=384, max=69747, avg=10262.24, stdev=5722.72 lat (usec): min=398, max=69798, avg=10311.27, stdev=5723.76 clat percentiles (usec): | 1.00th=[ 881], 5.00th=[ 1663], 10.00th=[ 2606], 20.00th=[ 4490], | 30.00th=[ 6390], 40.00th=[ 8225], 50.00th=[10159], 60.00th=[11994], | 70.00th=[13829], 80.00th=[15664], 90.00th=[17957], 95.00th=[19530], | 99.00th=[22152], 99.50th=[23200], 99.90th=[28967], 99.95th=[35390], | 99.99th=[58459] bw ( KiB/s): min=84032, max=111104, per=100.00%, avg=99154.29, stdev=5994.62, samples=120 iops : min= 2626, max= 3472, avg=3098.57, stdev=187.33, samples=120 lat (usec) : 500=0.09%, 750=0.46%, 1000=0.95% lat (msec) : 2=5.26%, 4=10.53%, 10=32.09%, 20=46.96%, 50=3.65% lat (msec) : 100=0.02% cpu : usr=9.95%, sys=26.29%, ctx=186005, majf=0, minf=266 IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=100.0%, >=64=0.0% submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0% complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.1%, 64=0.0%, >=64=0.0% issued rwt: total=185941,0,0, short=0,0,0, dropped=0,0,0 latency : target=0, window=0, percentile=100.00%, depth=32 Run status group 0 (all jobs): READ: bw=96.8MiB/s (102MB/s), 96.8MiB/s-96.8MiB/s (102MB/s-102MB/s), io=5811MiB (6093MB), run=60010-60010msec Disk stats (read/write): sdb: ios=185497/86, merge=2/46, ticks=1893688/4600, in_queue=1898360, util=99.92% # Crucial MX500 # test: (g=0): rw=randread, bs=(R) 32.0KiB-32.0KiB, (W) 32.0KiB-32.0KiB, (T) 32.0KiB-32.0KiB, ioengine=libaio, iodepth=32 fio-3.1 Starting 1 process Jobs: 1 (f=1): [r(1)][100.0%][r=249MiB/s,w=0KiB/s][r=7964,w=0 IOPS][eta 00m:00s] test: (groupid=0, jobs=1): err= 0: pid=3684: Fri Jan 4 07:24:29 2019 read: IOPS=7958, BW=249MiB/s (261MB/s)(14.6GiB/60004msec) slat (usec): min=8, max=781, avg=39.09, stdev=26.28 clat (usec): min=351, max=11790, avg=3971.78, stdev=850.49 lat (usec): min=418, max=11805, avg=4011.70, stdev=849.55 clat percentiles (usec): | 1.00th=[ 2540], 5.00th=[ 2900], 10.00th=[ 3097], 20.00th=[ 3359], | 30.00th=[ 3556], 40.00th=[ 3720], 50.00th=[ 3884], 60.00th=[ 4015], | 70.00th=[ 4178], 80.00th=[ 4424], 90.00th=[ 4686], 95.00th=[ 5211], | 99.00th=[ 7177], 99.50th=[ 7308], 99.90th=[ 7701], 99.95th=[ 7832], | 99.99th=[ 8029] bw ( KiB/s): min=249856, max=255872, per=100.00%, avg=254709.22, stdev=592.04, samples=120 iops : min= 7808, max= 7996, avg=7959.62, stdev=18.49, samples=120 lat (usec) : 500=0.01%, 750=0.01%, 1000=0.01% lat (msec) : 2=0.07%, 4=58.38%, 10=41.54%, 20=0.01% cpu : usr=13.17%, sys=45.78%, ctx=278702, majf=0, minf=265 IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=100.0%, >=64=0.0% submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0% complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.1%, 64=0.0%, >=64=0.0% issued rwt: total=477571,0,0, short=0,0,0, dropped=0,0,0 latency : target=0, window=0, percentile=100.00%, depth=32 Run status group 0 (all jobs): READ: bw=249MiB/s (261MB/s), 249MiB/s-249MiB/s (261MB/s-261MB/s), io=14.6GiB (15.6GB), run=60004-60004msec Disk stats (read/write): sda: ios=476506/5, merge=0/1, ticks=1876020/136, in_queue=1875680, util=99.91% I've yet to attach the disk directly to the mobo. It's a bit fiddly as the most accessible port is meant for the DVD drive and I think it's speed is slower than the others. The speed of the ATA ports is lower than you might expect (this machine is fairly old): [ 2.725849] ahci 0000:00:11.0: version 3.0 [ 2.726434] ahci 0000:00:11.0: AHCI 0001.0200 32 slots 4 ports 3 Gbps 0xf impl SATA mode [ 2.726439] ahci 0000:00:11.0: flags: 64bit ncq sntf ilck pm led clo pmp pio slum part [ 2.734592] scsi host0: ahci [ 2.741769] scsi host1: ahci [ 2.747197] scsi host2: ahci [ 2.752589] scsi host3: ahci [ 2.752731] ata1: SATA max UDMA/133 abar m1024@0xfe6ffc00 port 0xfe6ffd00 irq 25 [ 2.752735] ata2: SATA max UDMA/133 abar m1024@0xfe6ffc00 port 0xfe6ffd80 irq 25 [ 2.752739] ata3: SATA max UDMA/133 abar m1024@0xfe6ffc00 port 0xfe6ffe00 irq 25 [ 2.752742] ata4: SATA max UDMA/133 abar m1024@0xfe6ffc00 port 0xfe6ffe80 irq 25 [...] [ 3.228107] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 3.228941] ata1.00: supports DRM functions and may not be fully accessible [ 3.228979] ata1.00: ATA-10: CT500MX500SSD1, M3CR023, max UDMA/133 [ 3.228982] ata1.00: 976773168 sectors, multi 1: LBA48 NCQ (depth 31/32), AA [ 3.229920] ata1.00: supports DRM functions and may not be fully accessible [ 3.230705] ata1.00: configured for UDMA/133 [ 3.231082] scsi 0:0:0:0: Direct-Access ATA CT500MX500SSD1 023 PQ: 0 ANSI: 5 [ 3.231546] sd 0:0:0:0: Attached scsi generic sg0 type 0 [ 3.231767] sd 0:0:0:0: [sda] 976773168 512-byte logical blocks: (500 GB/466 GiB) [ 3.231770] sd 0:0:0:0: [sda] 4096-byte physical blocks [ 3.231790] sd 0:0:0:0: [sda] Write Protect is off [ 3.231793] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 [ 3.231826] sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 3.232091] ata2: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 3.233529] sda: sda1 sda2 sda3 [ 3.236030] ata3: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 3.236057] ata4: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 3.236617] ata4.00: ATA-9: WDC WD20EZRX-00D8PB0, 80.00A80, max UDMA/133 [ 3.236620] ata4.00: 3907029168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA [ 3.236843] ata3.00: ATA-9: ST2000DM001-1CH164, CC29, max UDMA/133 [ 3.236846] ata3.00: 3907029168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA [ 3.237178] ata4.00: configured for UDMA/133 [ 3.237669] ata3.00: configured for UDMA/133 [ 3.240132] sd 0:0:0:0: [sda] supports TCG Opal [ 3.240136] sd 0:0:0:0: [sda] Attached SCSI disk [ 3.242623] ata2.00: FORCE: horkage modified (noncq) [ 3.242683] ata2.00: supports DRM functions and may not be fully accessible [ 3.242686] ata2.00: ATA-11: Samsung SSD 860 EVO 500GB, RVT01B6Q, max UDMA/133 [ 3.242689] ata2.00: 976773168 sectors, multi 1: LBA48 NCQ (not used) [ 3.245518] ata2.00: supports DRM functions and may not be fully accessible [ 3.247611] ata2.00: configured for UDMA/133 [ 3.247915] scsi 1:0:0:0: Direct-Access ATA Samsung SSD 860 1B6Q PQ: 0 ANSI: 5 [ 3.248390] ata2.00: Enabling discard_zeroes_data [ 3.248493] sd 1:0:0:0: [sdb] 976773168 512-byte logical blocks: (500 GB/466 GiB) [ 3.248514] sd 1:0:0:0: [sdb] Write Protect is off [ 3.248517] sd 1:0:0:0: [sdb] Mode Sense: 00 3a 00 00 [ 3.248551] sd 1:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 3.248777] ata2.00: Enabling discard_zeroes_data [ 3.249093] sd 1:0:0:0: Attached scsi generic sg1 type 0 [ 3.249398] scsi 2:0:0:0: Direct-Access ATA ST2000DM001-1CH1 CC29 PQ: 0 ANSI: 5 [ 3.249649] sd 2:0:0:0: Attached scsi generic sg2 type 0 [ 3.250007] scsi 3:0:0:0: Direct-Access ATA WDC WD20EZRX-00D 0A80 PQ: 0 ANSI: 5 [ 3.250266] sd 3:0:0:0: Attached scsi generic sg3 type 0 [ 3.250477] sd 2:0:0:0: [sdc] 3907029168 512-byte logical blocks: (2.00 TB/1.82 TiB) [ 3.250480] sd 2:0:0:0: [sdc] 4096-byte physical blocks [ 3.250512] sd 2:0:0:0: [sdc] Write Protect is off [ 3.250514] sd 2:0:0:0: [sdc] Mode Sense: 00 3a 00 00 [ 3.250586] sd 2:0:0:0: [sdc] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 3.250619] sd 3:0:0:0: [sdd] 3907029168 512-byte logical blocks: (2.00 TB/1.82 TiB) [ 3.250622] sd 3:0:0:0: [sdd] 4096-byte physical blocks [ 3.250739] sd 3:0:0:0: [sdd] Write Protect is off [ 3.250741] sd 3:0:0:0: [sdd] Mode Sense: 00 3a 00 00 [ 3.250811] sd 3:0:0:0: [sdd] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 3.254586] sdb: sdb1 sdb2 sdb3 sdb4 [ 3.255158] ata2.00: Enabling discard_zeroes_data [ 3.257058] sd 1:0:0:0: [sdb] supports TCG Opal [ 3.257063] sd 1:0:0:0: [sdb] Attached SCSI disk [ 3.274972] sdd: sdd1 [ 3.275532] sd 3:0:0:0: [sdd] Attached SCSI disk [ 3.276090] sdc: sdc1 [ 3.276548] sd 2:0:0:0: [sdc] Attached SCSI disk -- Sitsofe | http://sucs.org/~sits/