Hi, 

 

Just a looking for a little help / clarification on identifying a drive that I just shucked.

 

Recently picked up an 8TB Seagate Expansion External drive to add capacity to my unraid server as they were reasonably prices (for Canadians) @ 239 CAD on Amazon.ca.

Opened up the enclosure expecting the usual Seagate Archive Drive (ST8000AS0002) but was surprised to find Seagate BarraCuda ST8000DM0004 instead

 

Just wanted to see in the community could clarify some details on the drive I had received?

Searching the drive model only brings up the Seagate Barracuda Pro Model in the 8TB Capacity, which shows a 7200rpm drive with a 256MB cache.

In running a few hdparm commands that had been suggested in other threads (output below), It seems this drive is a 5400rpm drive with an unknown cache.

 

 

In looking through other posts regarding shucking externals, I ran a few hdparm commands as follows.

 

/dev/sde:
 max sectors   = 15628053168/15628053168, HPA is disabled

 

From hdparm -i

/dev/sde:

 Model=ST8000DM004-2CX188, FwRev=0001, SerialNo=WG8019TJ
 Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=0
 BuffType=unknown, BuffSize=unknown, MaxMultSect=16, MultSect=off
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=15628053168
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes:  pio0 pio1 pio2 pio3 pio4 
 DMA modes:  mdma0 mdma1 mdma2 
 UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6 
 AdvancedPM=no WriteCache=enabled
 Drive conforms to: unknown:  ATA/ATAPI-4,5,6,7

 

From hdparm -I

 cache/buffer size  = unknown
Nominal Media Rotation Rate: 5425

 

How can I tell, or what to I look for to verify if this is a PMR or SMR drive?

How can I find out the actual cache size of the drive?

 

Any help or info is appreciated.

 

Cheers!

 

 

http://www.seagate.com/www-content/product-content/barracuda-fam/barracuda-new/en-us/docs/100804071d.pdf

 

Wrong link, linked the ST8000DM0004 instead of the ST8000DM004, all info available suggests that this is in fact an SMR drive.

Edited December 15, 20178 yr by johnnie.black

Cache buffer - 256MB

Recording method - Perpendicular

 

Edit: See above

Edited December 6, 20178 yr by johnnie.black

Thanks for the link

 

So, am I correct to assume that it is a Pro Drive based on the model number, and that the drive I shucked just has an older label? (not listing it as a pro drive).

And is there any way from unraid or command line that I can verify the rotational speed and cache size?

 

Thanks again

 

There is only one ST8000DM0004.

 

You can use the speed test scrip/plugin to confirm the rpms, it should start at ~220MB/s, no idea how to confirm the cache but it has to be what's on the Seagate specs.

Hello everyone, I just found the thread regarding the Seagate Backup Plus hub external drive, which I own too since yesterday. Mine came fitted with the same Barracuda shown in the above picture. I do not know if it is a good or a bad thing, while comparing the Archive drive the Seagate Bakup Plus hub external drive is usually fitted with and that Barracuda.

It is most definitely not a Barracuda Pro, the Pro's comes in a totally different metal case, they're filled with helium, and their top cover is completely flat which this Barracuda's isn't

Also the model number is ST8000DM004 and not ST8000DM0004 (two zeros not three), a model which is listed in their Barracuda range together with ST6000DM003, ST4000DM004, ST3000DM007 and ST2000DM005.

I decided to open the enclosure, the damn clips and the plastic they used for the case makes it impossible to open the external enclosure without breaking at least half of them, but anyway, I opened it and with the hard drive now as an internal I decided to take off the electronic pcb to check what type of buffer size is the drive coming with... It is not hard to spot the ram they decided to use, a Samsung DDR3L  BGA chip SEC 646 K482G1646F BCK0, and searching about that I found out it is a  2Gb DDR3L in 16*128 accessing mode. So 2Gb divided by 8 means that the drive is coming with 256MB of DDR3L twice the amount the Archive drives are coming with. I don't know if the cache works in the same way as the one is by the Pro ("multi-tier caching technology (MTC Technology), an intelligent caching architecture for maximized performance), and whether  AgileArray feature is available ("optimizes drive performance via error recovery control, dual-plane balancing, and power management), these features maybe available only for Pro's.

From Barracuda 100805918d.pdf I see that the recording method is neither Perpendicular as the PRO's  nor Shingled as the Archive but TGMR and the drive is using 4 platters / 8 heads configuration when the 8TB Archive drive is working in a 6 platters 12 heads configuration, and knowing that it is not helium filled drive I think it is a better option in terms of life expectancy than a 6 platters 12 heads drive, with 2 platters 4 heads less, yet coming with the same capacity that means Seagate is using 2TB platters on this drive, and that is confirmed by the pdf.

Compared to the Pro, this one has an advertised 600000 load/unload cycles, double the amount the Pro which is advertised with only 300k the same amount Archive drives are credited with (300k). 

Also regarding the workload this one is advertised as <55TB per year while the Pro with 300TB per year and the Archive with 180TB/year.

Running SeaTools the reported annual workload is much higher than the advertised one: 168,83TB/year.

To conclude, I think the ones who find inside their Seagate external drive a Barracuda and not an Archive could be happy, double the cache size than Archive, less platters for the same capacity yet less workload per year compared to the Archive.

I do not know whether TGMR recording is better than SMR, but i guess Pro's perpendicular is the best recording method.

I hope these findings to be useful for anyone else who's going to find a Barracuda inside its external newly purchased external drive

100805918d.pdf

Edited August 9, 20178 yr by domogled
new information benchmarks and pictures

Hello,

 

I was about to buy the Archive one ST8000AS0002 8TB 3y warranty, but also found ST8000DM004 with same price and 5y warranty.

Also i see more cache + your review ...so ill pick the ST8000DM004 . Hope it will be fine.

ST8000DM004 is a good drive.  It's basically the 8TB version of the venerable ST4000DM000 - slow and reliable, and readily available by shucking.

i ordered it...as i wasnt sure abot the SMR technology - use it mostly for store movies/music for my media center

 

I have some DM disk already but is 4tb...also ST4000VN (sold) - which i had over 2y and no issue at all

On Thursday I picked up another 8TB External Seagate Drive, this time from Newegg. The model found inside is ST8000DM004-2CX188. It seems like they definitely switched over to this model. I'm not sure if they're using the Shingled Archive drives in externals anymore.

 

For the parity drive, I'll have to run a few drive speed tests to determine which model would be better. I'm thinking the DM004 would be slightly better than the AS0002.

11 minutes ago, BRiT said:

I'll have to run a few drive speed tests to determine which model would be better.

He's one from a DM004 I shucked a few weeks ago- https://forums.lime-technology.com/topic/37847-seagate-8tb-shingled-drives-in-unraid/?do=findComment&comment=589683

 

7 hours ago, BRiT said:

I'm not sure if they're using the Shingled Archive drives in externals anymore.

 

From the available info on the net the ST8000DM004 is also shingled.

Yes, the ST8000DM004 is SMR and is much cheaper than the ST8000DM0004 which is PMR and the one filled with helium. I think those got mixed up above. 

Hey I hope people are still reading this thread however I've just shucked this drive last night and haven't been able to get unraid to detect it as an unassigned device, any thoughts on what I'm missing here? Was there a pin I needed to block out or anything? This drive did come out of a known working case and was formatted before shucking and retested post shuck but still not being recognized. Any thoughts or assistance would be greatly appreciated. Thanks!

Check if the drive shows up in BIOS.

If it doesn't then reconnect it with a different SATA cable and check in BIOS again.

If the drive is still not recognized then change a  SATA port on the motherboard.

8 hours ago, Lolight said:

Check if the drive shows up in BIOS.

If it doesn't then reconnect it with a different SATA cable and check in BIOS again.

If the drive is still not recognized then change a  SATA port on the motherboard.

Thank you I  will give that a try