Seagate 8TB Shingled Drives in UnRAID


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It is disturbing that Seagate dropped the Workload Rate Limit so much on the latest drives.    Not sure that's a "real" change as much as simply a lower spec for drives slated for the consumer market.    Seagate rates their Enterprise class drives with a WRL of 550TB/yr, and their "near line" drives at 180TB/yr ... I suspect the 55TB figure is simply because this is a consumer oriented drive -- perhaps more of a marketing difference than a real technical concern.

 

Although they don't differentiate reads from writes in the computation of the WRL, I also suspect that writes are FAR more important in terms of actual degradation of the performance.    (That's certainly true for SSDs)   And of course a parity check is virtually all reads.

 

Bottom line:   I doubt the WRL figure is really anything to be concerned about.

 

It is, however, very interesting that the speeds aren't better on the v4 drives, especially since that model # is supposedly a 7200rpm drive.   I can't find a link that confirms it's using 2TB platters, however ... Johnnie:  Are you certain about the platter count?   I wasn't aware anyone was shipping anything larger than 1.5TB platters on PMR drives.  (WD ships 1.5TB platters on their 12TB helium units, which are PMR; and manages to stretch that to 1.75TB/platter on the 14TB shingled version of that drive)

 

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7 minutes ago, garycase said:

Johnnie:  Are you certain about the platter count?   I wasn't aware anyone was shipping anything larger than 1.5TB platters on PMR drives

 

These new disks are reportedly shingled as well, platter count is in Seagate's specs, rpm are not specified, but if they really are 2TB/platter it has to be lower than 5400rpm to only have the same performance as the old 1.33TB/platter drives.

 

http://www.seagate.com/www-content/product-content/barracuda-fam/barracuda-new/en-us/docs/100805918d.pdf

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Very interesting.   The specs also show a max sustained transfer rate of 190MB/s -- the same as the archive drives.   Doesn't make sense with the higher density platters unless they are indeed spinning appreciably slower to achieve the higher platter density.    But the drive is shown as a 7200rpm drive (at least in Amazon's listing for it):

https://www.amazon.com/Seagate-BarraCuda-3-5-Inch-Internal-ST8000DM004/dp/B07211QYRC/ref=sr_1_2?s=electronics&ie=UTF8&qid=1505338436&sr=1-2&keywords=ST8000DM004

 

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1 minute ago, garycase said:

But the drive is shown as a 7200rpm drive (at least in Amazon's listing for it):

 

7200 rpm they are not for sure, I suspect they are around 5000rpm, it's the only way the performance makes sense, they also use very little power, also consistent with low/lower rpm:

 

 

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40 minutes ago, HellDiverUK said:

I'd wager the DM004 is the same mechanism but with marginally different firmware.

 

You'd lose bet, completely different disks, just some obvious differences

 

ST8000DM004 / ST8000VN0002:

 

Maximum sustained data transfer rate - 190MB/s / 230MB/s

Number of disks/heads - 4/8 - 6/12

Idle power - 3.4w / 7.6w

 

 

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Agree with johnnie => the disk are VERY different.    The most perplexing thing about the performance of the DM004 is that it's so much slower than the previous version even though they're significantly improved the areal density of the platters.   This almost certainly means they're simply running them at a much lower rpm ... which is also supported by the very low power consumption figures.

 

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I'm liking the Best Buy Easystore 8T, with the WD REDS inside. They are also a bit slower than the older archive drives (of which I have several), but just like that they are not shingled. And the drives are easy to shuck without damaging the case tabs and voiding the warranty.

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  • 5 weeks later...

ok, I've joined the 8TB club!!

 

First drive was DOA - powered up with unbelievably loud (scared me to death!) and then wasn't even visible in BIOS.  2nd drive worked perfectly - precleared in 33hours (1 pass):

 

############################################################################################################################
#                                                                                                                          #
#                                         unRAID Server Preclear of disk Z840QTHH                                          #
#                                       Cycle 1 of 1, partition start on sector 64.                                        #
#                                                                                                                          #
#                                                                                                                          #
#   Step 1 of 5 - Pre-read verification:                                                   [4:16:13 @ 520 MB/s] SUCCESS    #
#   Step 2 of 5 - Zeroing the disk:                                                       [14:36:35 @ 152 MB/s] SUCCESS    #
#   Step 3 of 5 - Writing unRAID's Preclear signature:                                                          SUCCESS    #
#   Step 4 of 5 - Verifying unRAID's Preclear signature:                                                        SUCCESS    #
#   Step 5 of 5 - Post-Read verification:                                                 [14:30:05 @ 153 MB/s] SUCCESS    #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
############################################################################################################################
#                              Cycle elapsed time: 33:23:08 | Total elapsed time: 33:23:09                                 #
############################################################################################################################


############################################################################################################################
#                                                                                                                          #
#                                               S.M.A.R.T. Status default                                                  #
#                                                                                                                          #
#                                                                                                                          #
#   ATTRIBUTE                    INITIAL  CYCLE 1  STATUS                                                                  #
#   5-Reallocated_Sector_Ct      0        0        -                                                                       #
#   9-Power_On_Hours             0        33       Up 33                                                                   #
#   183-Runtime_Bad_Block        0        0        -                                                                       #
#   184-End-to-End_Error         0        0        -                                                                       #
#   187-Reported_Uncorrect       0        0        -                                                                       #
#   190-Airflow_Temperature_Cel  29       39       Up 10                                                                   #
#   197-Current_Pending_Sector   0        0        -                                                                       #
#   198-Offline_Uncorrectable    0        0        -                                                                       #
#   199-UDMA_CRC_Error_Count     0        0        -                                                                       #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
############################################################################################################################
#   SMART overall-health self-assessment test result: PASSED                                                               #
############################################################################################################################


--> ATTENTION: Please take a look into the SMART report above for drive health issues.

--> RESULT: Preclear Finished Successfully!.


root@Highlander:/usr/local/emhttp#

 

Edited by DZMM
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Seagate's drives fitted to external boxes tend to have slightly different firmware than the 'proper' drives.  Two of my ST4000DM000 drives were shucked, and they head park much more than the ST4000DM000 I bought as a normal bare drive.  I tried upgrading the firmware on the shucked drives, but the original firmware wasn't recognised by the firmware update utility, so couldn't be done.

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Ah Johnnie, just seen this one!

I'll confirm I've shucked a dozen of the Backup plus, 10 from Amazon with the DM004 drives in and a couple from ebuyer with the SMR archive drives in. The archive drives are a little slower and drop to 30 MB/s after a minute or so of transfer (due to the re-read buffering and compositing of data ready to rewrite I presume). I can confirm that my DM004 based drives run MUCH faster, and sustain approx 200MB/s for hours and hours at a time (I've filled them up with 'real' data on my workstation before putting them into drive pool service). Whilst there's not much information on these 'compute' drives it seems about right for a modern PMR/TGMR drive spinning at 5240 rpm.

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13 minutes ago, andynuke said:

Ah Johnnie, just seen this one!

I'll confirm I've shucked a dozen of the Backup plus, 10 from Amazon with the DM004 drives in and a couple from ebuyer with the SMR archive drives in. The archive drives are a little slower and drop to 30 MB/s after a minute or so of transfer (due to the re-read buffering and compositing of data ready to rewrite I presume). I can confirm that my DM004 based drives run MUCH faster, and sustain approx 200MB/s for hours and hours at a time (I've filled them up with 'real' data on my workstation before putting them into drive pool service). Whilst there's not much information on these 'compute' drives it seems about right for a modern PMR/TGMR drive spinning at 5240 rpm.

 

Those DM004 disks are shingled as well, and their performance is similar to the archive drives, although they should be faster due to the higher density platters, maybe they spin at a lower rpm:

 

 

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In my real world experience. Filling them with 'real' data (mostly terabytes of mkv BluRay Rips), the DM004's are running transfers attached directly to the motherboard at Circa 200MB/s for hour after hour. (inline with the HDtach tests) until the drive geometry starts to slow them down naturally.

The SMR Drives would start well, at 160-180 and quite often run out of steam after a few minutes and drop to 30MB/s and never recover?

what makes you think the DM004's are SMR? Looking at the seagate 'compute' specs and the performance. I'd be tempted to say otherwise?

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26 minutes ago, FrozenGamer said:

Is it reliable which externals hold the faster drives?  so far for me, the hub ones are archive drives and the expansion was fast.  This is based on a purchase about 5 months ago.  Huge difference in performance for me between the two.


Not from what I can tell. The 2 that had 'Archive' drives in for me came from ebuyer. (i use these as cold storage archives, so I'm not too bothered). Unfortunately, I threw all the empty boxes in the loft but they don't appear to have any external differences. until you shuck the drive. Then it's pretty obvious as they are labelled either Barracuda 'Compute' (these are the ST8000DM004-2CX188) or the 'Archive' drives in the case of the Ebuyer backup plus hubs. I'll drag them all out of the loft tomorrow and see if I can identify a pattern. (y) 

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The SMR Drives would start well, at 160-180 and quite often run out of steam after a few minutes and drop to 30MB/s and never recover?

  That's not what I and other SMR users experience, I have a server with 8TB archive drives only and find that for large files speed is constant, e.g., see the example below for a 150GB total transfer.  

59eb8061d9360_Screenshot2017-07-2313_50_52.png.48a6559a77aee03a3771beb1785c063a.png

 

 

 

what makes you think the DM004's are SMR? Looking at the seagate 'compute' specs and the performance. I'd be tempted to say otherwise?

  While I can't be 100% sure since Seagate goes out of its way not to mention SMR, I'm 99.99% sure since according to the specs that model uses 2TB platters, SMR it's currently the only way to achieve that density, AFAIK the largest PMR drive is the HGST 12TB Helium, and that one has 8 platters, so it's 1.5TB/platter, HGST just announced a 14TB SMR drive and it's "just" 1.75TB/platter. 

 

 

 

 

 

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  • 3 weeks later...
12 hours ago, garycase said:

Just out of curiosity, why did you sell them?   Getting larger drives?   Having issues?   Moving to PMR tech drives?  etc.

 

 

I have three 8TB WD Whites now, which are quieter and use less power.  The Seagates were worth more used as they still had warranty, so they were the ones to go.

 

I had no problems with them, and would still recommend to anyone running unRAID. 

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Outside of the performance of the two drives in questions, it all depends on your array usage patterns.

 

Assuming only a single write to the array at a time ...

In normal write mode, writes to the array will always be as slow as the slowest of the 2 disks involved (parity and data).

In turbo-write mode, writes to the array will still be as slow as the slowest of the 2 disks (parity and data), however the overall process can be faster since it cuts down on the latency of the data and parity drives.

 

Assuming multiple writes to different drives in the array at a time ...

Having a faster parity drive can improve overall performance.

 

As to the two drives you asked about, I have no idea which Seagate drive is more performant, the archive or the barracuda.

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  • 3 months later...

One of two ST8000AS0002 8TB (1NA17Z) drives I ordered back in November 2015 is starting to fail with sector read errors. These drives are in my backup server and pretty much only written to with new files, files are almost never deleted or replaced (excluding preclear test). Noticed things last night when I tried to copy a file from it and it kept failing with a network error and started a read scan.

 

My confidence in Seagate has been waning, got a WD 8TB Red arriving this evening to replace it.

 

ID# ATTRIBUTE_NAME          VALUE WORST THRESH FAIL RAW_VALUE
  5 Reallocated_Sector_Ct   100   100   010    -    8
183 Runtime_Bad_Block       099   099   000    -    1
187 Reported_Uncorrect      065   065   000    -    35
189 High_Fly_Writes         098   098   000    -    2
197 Current_Pending_Sector  100   100   000    -    208
198 Offline_Uncorrectable   100   100   000    -    208

 

Edited by jbartlett
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I am about to buy 5 x 12tb seagate ironwolfs to replace my 6 x archives. As this is going to be a very expensive purchase, I just need to know if this ok or not? I would prefer to buy 14tb/16tb hdd but I am not sure when they will be out. I need to make a decision soon as the archives warranties are running out in about a month.

 

 

Sent from my iPhone using Tapatalk

 

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