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Seagate 8TB Archive Drive in FreeNAS?

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DGenerateKane

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Anybody seen the 8TB Seagate Archive HDD? Model #: ST8000AS0002 to be specific. Is it viable to use in FreeNAS? I'd like to get 5 for my machine but I'm unsure if it would be recommended or not for FreeNAS.
 

cyberjock

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I don't have any of them, and I don't think anyone in the forum has wanted to spend that kind of cash on a per-disk basis. But Seagate is really in the sh*thole with many people because of their poor quality disks. So I wouldn't go that route just because of the brand. Aside from that, I don't see any reason why they can't be used for archival data.
 

mav@

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Those drives are SMR. Without special filesystem support (absent in ZFS) they may be quite slow on random write/rewrite patterns. I had no chance to test them in practice, but from theoretical knowledge I would avoid them, if possible.
 

Tywin

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Those drives are SMR. Without special filesystem support (absent in ZFS) they may be quite slow on random write/rewrite patterns. I had no chance to test them in practice, but from theoretical knowledge I would avoid them, if possible.
My understanding is they use a similar strategy to SSDs, where they just write a new block instead of updating the old one, and eventually garbage collect it. Suffice to say Seagate engineers know a lot more about the system than any of us do, so I wouldn't put it out on a "theoretical" basis. That said, as with any new technology, proper testing is in order.
 

zambanini

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it is not just a new block, the drive has to complete rewrite some "circles" on the disk. I had the original seagate archive 8tb (without v2): sequential reading was as fast as 8MB/sec (disk has been completely rewritten a couple of times, freespace reduced to 50%, but just ext4) I did not do any further tests
 

Tywin

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it is not just a new block, the drive has to complete rewrite some "circles" on the disk. I had the original seagate archive 8tb (without v2): sequential reading was as fast as 8MB/sec (disk has been completely rewritten a couple of times, freespace reduced to 50%, but just ext4) I did not do any further tests
.. is that a typo? I don't see how an 8 MiB/s drive could even be released.
 

mav@

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.. is that a typo? I don't see how an 8 MiB/s drive could even be released.
I would not be so surprised. Unlike SSDs, HDDs has huge seek time. Implementing SSD-like write strategy and later garbage collection may turn linear read into random one, for which 8MB/s is not really surprising.

There is simple reason why Seagate organizes numerous presentations for OS and FS developers about how to efficiently use those devices -- they simply don't work well with general purpose file systems.
 

cyberjock

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Slow down gents. I knew it was SMR when I saw the part number. Beat you all to the punch and discussion...


#1. The drive does more than 8MB/sec. It does something like 110-130MB/sec from some website I read but can't find now. Seagate claims an average speed of 150MB/sec. Yes, they are slower than the somewhat comparable 6TB WD Reds, but not so slow that they are almost useless (aka 8MB/sec)
#2. He said "Seagate 8TB Archive Drive". That means rarely need to access, density is king and performance isn't super important. I'd take it to also mean that if the disks did "just" 100MB/sec he'd still be happy. I know many people can't even backup their data right now at a rate of 100MB/sec. ;)

I will agree that SMR is a relatively new technology. I hate Seagate personally, but at the same time I wouldn't expect them to market a drive that they *know* will fail at a high rate, will perform at some horribly unacceptable speed, or generally have some downside that makes it useless (that kind of publicity will hurt them and they've got plenty of bad publicity lately). Even at 25MB/sec, it would take 88 hours to fill the drive. Not horribly unreasonable if you have a RAID of them at that speed, but at 8MB/sec that would take over 11 days!

So calm down. SMR may suck. But it doesn't suck so badly that you wouldn't want to use it. ;)
 

wtfuar

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This HDD has no error *recovery (TLER/SCT/ERC -vendor specific) so I wont use it in my RAID build.
But I use it together with 5x4TB WD Green in Stripe as offline Backup.

Also to mention that smartd reports for APM:
Code:
freenas smartd[3377]: Device: /dev/da23 [SAT], CHECK POWER STATUS returned 129, not ATA compliant, ignoring -n Directive

on the ST8000AS0002.
I set it to 128 and it is ignored I think.

You may find this Link interesting, the test is in german but the ATTO benchmark screen shots are probably usefull for you to get an impression in the performance.

Edit: made corrections
*Thx to cyberjock
 
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cyberjock

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This HDD has no error correction (TLER/SCT/ERC -vendor specific) so I wont use it in my RAID build.
That is not error correction. That is error recovery. All hard drives have their own error correction via ECC. ;)
 

Z300M

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That is not error correction. That is error recovery. All hard drives have their own error correction via ECC. ;)
Maybe we shouldn't really be using drives without TLER/ERC/SCT in FreeNAS machines, but is there any good reason why FreeNAS itself couldn't have an option to wait a few seconds before dropping an apparently unresponsive drive from a vdev? I.e., do in FreeNAS what those other technologies do within the drive itself?
 

Bidule0hm

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It's ZFS that manage this and IIRC there's already a delay of 1 minute (or 30 seconds, not 100% sure) :)
 

Z300M

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It's ZFS that manage this and IIRC there's already a delay of 1 minute (or 30 seconds, not 100% sure) :)
Do TLER/ERC/SCT have any benefit for FreeNAS machines at all then? Are they more important for hardware RAID?
 

Bidule0hm

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Yes, they have the benefit to not hang a pool because one drive is hanging ;)

Yes, I think it's more important for H/W RAID than for ZFS because if the controller drop more drives than the number of parity drives you have because they timeout you'll not be happy with the result... As ZFS use a longer timeout delay it should not drop a drive as often on average.
 

Ericloewe

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TLER is still better, because it allows ZFS to just take care of the problem quickly and get on with life. Corruption happens, deal with it quickly, log it and move on.
 

DGenerateKane

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So is the consensus this drive isn't suitable for FreeNAS?
 

Ericloewe

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Depends on your requirements. Everyone has a different set.
 

DGenerateKane

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Well my plans were to move my HTPC media to them, which is streamed to my HTPC's daily. I typically transfer new media to my NAS every once in a while, so it could end up being several hundred gigabytes. Though I could transfer every time I get new media, so the size would be considerably less. Alternatively if that isn't an ideal use for them, they could be storage for all my other files which currently reside on over a dozen drives that are not in the NAS. Those files would be accessed rarely unlike the HTPC media, and would only see small amounts of data added irregularly.
 

Z300M

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If these drives are intended for archiving data but are not recommended (not even by Seagate) for attachment to a RAID controller, then isn't the only way to ensure the safety of the archived data to have two or more such drives to which the files are copied separately? (And it just occurred to me: with drives that are mirrored -- whether using FreeNAS or hardware RAID -- are there periodic checks for consistency between the two or more sets of data?)
 
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