xerces8

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    Seagate 8TB Shingled Drives in UnRAID

    in Storage Devices and Controllers

    Posted

    Linear reads on SMR are the same as on non-SMR drives.

    The biggest difference is in the random write test (10 times faster than non-SMR due to the track cache).

     

    And hammering it with a _lot_ of read/write requests (similar results as non-SMR except for the occasional long delay).

     

    Not exactly a one-click thing, but enough to get a few good hints.

    Any non-SMR external drives on the market?

    in Storage Devices and Controllers

    Posted · Edited by xerces8

    I got a WD My Book 8 TB (WDBBGB0080HBK-EESN) and after some testing it looks like a non-SMR drive.

     

    See CDM screenshot attached (the disk was 99.999% full, to make it "sweat", the test with 0% full is almost the same except the SEQ values being 199MB/s).

     

    Also test with FIO as per this post suggests it is not SMR. The summary:
      

    TEST: (groupid=0, jobs=1): err= 0: pid=4768: Tue Sep 10 22:24:49 2019
  write: IOPS=7, BW=73.2MiB/s (76.8MB/s)(85.8GiB/1200024msec)
    slat (usec): min=353, max=4294.0k, avg=2579.76, stdev=71064.79
    clat (usec): min=2, max=9319.4k, avg=69451.95, stdev=100307.35
     lat (msec): min=35, max=402895, avg=136.54, stdev=4401.42
    clat percentiles (msec):
     |  1.00th=[   41],  5.00th=[   47], 10.00th=[   51], 20.00th=[   57],
     | 30.00th=[   61], 40.00th=[   64], 50.00th=[   67], 60.00th=[   70],
     | 70.00th=[   74], 80.00th=[   80], 90.00th=[   87], 95.00th=[   93],
     | 99.00th=[  114], 99.50th=[  188], 99.90th=[  234], 99.95th=[  239],
     | 99.99th=[ 9329]
   bw (  KiB/s): min=19922, max=183585, per=100.00%, avg=144614.45, stdev=17834.58, samples=1226
   iops        : min=    1, max=   17, avg=13.38, stdev= 1.78, samples=1226
  lat (usec)   : 4=0.02%, 20=0.02%, 50=0.05%, 100=0.01%
  lat (msec)   : 50=9.84%, 100=87.85%, 250=2.17%, 500=0.02%
  cpu          : usr=0.33%, sys=0.42%, ctx=0, majf=0, minf=0
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=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=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=0,8788,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=1

Run status group 0 (all jobs):
  WRITE: bw=73.2MiB/s (76.8MB/s), 73.2MiB/s-73.2MiB/s (76.8MB/s-76.8MB/s), io=85.8GiB (92.1GB), run=1200024-1200024msec

     

    CDM602_exFAT_100%.png

    • Like 1

    Seagate 8TB Shingled Drives in UnRAID

    in Storage Devices and Controllers

    Posted

    On 12/15/2018 at 5:56 PM, xerces8 said:

    I have a 8TB Seagate Desktop drive (CystalDiskInfo says it is a ST8000DM004-2CX188, haven't shucked it yet).

    The interesting thing is, CDM shows normal (as in "not SMR") values for 4K writing (same as for reading, about 1 MB/s), unlike about 10 MB/s, like for example my other 5TB SMR drive.

     

     

    After filling it to about half and rerunning CDM, I got the typical values for 4K:  read about 0.5 MB/s, write 6 MB/s

    Seagate 8TB Shingled Drives in UnRAID

    in Storage Devices and Controllers

    Posted

    On 8/31/2017 at 11:40 PM, johnnie.black said:

     

    On further reading, looks like TGMR can still be SMR o.O, so probably shingled the same but with bigger platters, still better, wont comment on the warranty, you need to decide about that yourself.

    Hi!

     

    Is there more info on what exactly is TGMR?

     

    I have a 8TB Seagate Desktop drive (CystalDiskInfo says it is a ST8000DM004-2CX188, haven't shucked it yet).

    The interesting thing is, CDM shows normal (as in "not SMR") values for 4K writing (same as for reading, about 1 MB/s), unlike about 10 MB/s, like for example my other 5TB SMR drive.

     

    Regards,

    David