Biggest non-SMR HDD, suitable for a 4-bay NAS unit / RAID-5? SMR issues overblown?

[VirtualLarry]

Curious what HDD technology is up to these days. Heard rumors of 10TB HDDs appearing.

AFAIK, the previous largest was 8TB, and that was the Seagate Archive HDD, with SMR (shingled).

I bought a few Seagate Expansion Desktop External 5TB HDDs, which AFAIK are NOT SMR. I plan to shuck them and put them into a 4-bay NAS. (Hopefully, being just regular 5TB Seagate desktop drives, they won't drop out of a RAID-5. Hopefully Seagate hasn't gimped their firmware, to force purchasing of their more-expensive NAS drives.)

But, looking 3-5 years into the future, what size HDD will be available, that will be suitable for a 4-bay NAS? (It's my understanding that SMR drives are not suitable for RAID-5 at all.)

Are there non-SMR 10TB drives on the horizon?

Edit: Checked front page, found this:
http://www.anandtech.com/show/10470...near-future-speaking-with-seagate-cto-mark-re
http://www.anandtech.com/show/9858/seagate-hard-disk-drives-set-to-stay-relevant-for-20-years

And then this... Seagate to slash 8000 jobs? Ouch!
http://www.anandtech.com/show/10484/seagate-to-lay-off-over-8000-to-lower-its-costs

Edit: Do I really need to avoid SMR drives? There was I comment that I was reading on another site that said they were getting 100MB/sec from an SMR drive, and that the performance-related issues with SMR drives were overblown. Then again, I don't think that he was running it in a RAID-5.

http://www.storagereview.com/seagate_archive_hdd_review_8tb

With the attractively low price per TB that the Seagate Archive 8TB HDD has, it can be difficult to not consider purchasing a set for NAS storage. StorageReview strongly recommends against such usage, as at this time SMR drives are not designed to cope with sustained write behavior. Many contend that NAS shares tend to be very read-focused during normal operation. While that's true, the exception is when a drive fails and a RAID rebuild has to occur. In this case the results clearly show that this implementation of SMR is not a good fit for RAID.

To show this stark difference we compared two Seagate Archive HDDs (SMR) and two HGST He8 HDDs (PMR), both configured in RAID1. These were installed in a Synology DS1815+ and DS1515+ respectively, where a RAID1 volume was created and then a single drive was pulled to put the RAID-set into a degraded mode. The removed drive was then reinserted and a RAID rebuild initiated.

Below is a screenshot showing disk activity during the SMR RAID rebuild on top, where we see sustained write performance all over the map, including single digit throughput for long periods. This is compared to the PMR rebuild shown on the bottom half of the image which is able to stay over 100MB/s for most of the duration.

 

[Essence_of_War]

http://pcpartpicker.com/products/in...=a10&f=2&i=25,22,86&c=1024,768,512,256,128,64

Other than the Seagate archive, the rest of these are all 8TB non-SMR drives.

Are there non-SMR 10TB drives on the horizon?

My guess is "probably" but likely with He first.

Edit: Do I really need to avoid SMR drives? There was I comment that I was reading on another site that said they were getting 100MB/sec from an SMR drive, and that the performance-related issues with SMR drives were overblown. Then again, I don't think that he was running it in a RAID-5.

What is your workload. If it's a NAS that is storing mostly media (write once, read back many) and backups (write once, read occasionally to figure out what has changed) I think SMR drives could be a very reasonable choice.

 

[BSim500]

I don't really know about large 3.5" drives for NAS, but given the choice I'd personally avoid SMR. The new Seagate Ultra Slim 1-2TB drives are SMR:-
http://hexus.net/tech/reviews/storage/94174-seagate-backup-plus-ultra-slim-2tb/?page=2
http://www.storagereview.com/seagate_backup_plus_ultra_slim_review

1TB per 2.5" platter is impressive until you see those write speeds are way down at 10-40MB/s. Compare that to up to 110MB/s for non-SMR drives like the non-Ultra slim or the WD My Passport Ultra. The reason SMR might appear to be fast in some reviews is it could be writing on a "clean" drive which could make it benchmark faster than it will feel once you start filling it up. Fragmentation not only means the drive head has to move, it means it'll be having to rewrite surrounding data around each fragment which could massively bog it down. Depends on your workload though.

 

[WhoBeDaPlaya]

Seagate + new tech (SMR) == wait-and-see in my book.

Speaking of which, just buy a WD MyBook 8TB, shell it, and grab the juicy 7200/5400rpm Hitachi Ultrastar He8 inside. Upgraded my two duplicate file servers with them (see sig)

 

[nerp]

Seagate has a long road to go before I and legions of other people even consider using their drives. One good Backblaze report doesn't cut it, either.

 

[stlc8tr]

Edit: Do I really need to avoid SMR drives? There was I comment that I was reading on another site that said they were getting 100MB/sec from an SMR drive, and that the performance-related issues with SMR drives were overblown. Then again, I don't think that he was running it in a RAID-5.

http://www.storagereview.com/seagate_archive_hdd_review_8tb

That article said that the rebuild took almost 3X longer. For a really large array, that would mean insanely long rebuild times.

The HGST He8 HDDs completed its rebuild in 19 hours and 46 minutes. The Seagate Archive HDDs completed their rebuild in 57 hours and 13 minutes. Needless to say in a larger RAID group or with background activity taking place, that rebuild time will only get longer.

 

[dave_the_nerd]

Yeah, the main problem with SMR is the slow. If your NAS is bottlenecking everything anyway, no biggie.

The extra-long rebuild times do make it more tempting to restore the NAS from a backup rather than rebuild a RAID, uptime requirements and so forth permitting. And assuming you have good backups. (!)

 

[sdifox]

RAID and smr is a bad mix. HGST Ultrastar He10 comes in 10TB flavour.

https://www.amazon.com/HGST-Ultrastar-HUH721010AL5200-Internal-Drive/dp/B01GXUR98G/ref=sr_1_fkmr0_2?ie=UTF8&qid=1468632862&sr=8-2-fkmr0&keywords=ultrastar+he+10+10tb

 

[Essence_of_War]

Ask and ye shall receive

http://www.servethehome.com/seagate-guardian-series-10tb-drives-launched/

edit:

Sry missed the AT link!

http://www.anandtech.com/show/10496...s-10tb-hdd-portfolio-brings-helium-mainstream

To be clear, these are all non-SMR, helium drives, and it does sound like there is TLER market segmentation.