I got 9 seagate st3000nm0043 for 100€. It was a good deal anyway however they are smr.
So I wanted to build a NAS. My question: what’s the best cause of action now?
ZFS on smr is probably bad, however UNRAID with cmr parity drives might be fine. or just flip them on ebay?
Best regards
Unraid sounds seems like a viable solution to me.
Especially it you use cmr for the parity drives.
If you put a ssd in front for caching, you might never notice they are smr.
Be aware though, if you want to encrypt them, that it takes a very long time on smr drives.
I once encrypted an 8 TB seagate smr drive with luks.
It took 14 days nonstop.
A 8 TB cmr drive takes ~ 26 hours.
Also, 9 3TB drives for 100 € is a damn good price, even if they are smr 
I have different opinions on SMR drives than other people I guess.
In my opinion they work fine as long as your disk operations are mostly sequential. They work well with MDRAID and EXT4. Do not use them with LVM and never with ZFS. I don’t know about Unraid.
Apologies my initial post was a bit hasty. I was super busy when I replied and didn’t really think it through. I’m on vacation now, and I’m a massive nerd that loves storage so here I am.
Congratulations on the nice find!
@blessed Unraid will be fine with plenty of SSD cache.
CMR parity disk is a good move, obviously remember to make it bigger than the data disks or at lest the same size.
Definitely no zfs, I agree.
Now I’ve left this part until the end, @Blissed. I looked up this part code, and it shows as a, SED, not an SMR disk. It was also released in 2012, and SMR wasn’t introduced until 2013. This may depend on the manufacture date of your disks.
The datasheet for the model lists perpendicular recording technology, which is CMR.
An SED may be similarly slow, but obviously for very different reasons. Also you might want to take steps to clear the crypto keys off the disks before you use them, depending on how much you care.
I think people blew it out of proportion somewhat due to the general outrage at the unclear labeling.
“Don’t”
Or… if you do, just put them in a big JBOD and back it up. At least definitely do not use ZFS or a hardware raid controller (even intel onboard which are half software). The SMR re-write process requires enough time that a lot of raid implementations will consider the drive to have dropped during it - potentially initiating a rebuild which guess what… causes a heap of SMR re-write, which itself causes the controller to think it dropped, etc.
Perhaps with Ceph?
Perhaps, he’s got the right number of disks for a 3 node cluster.
I’m not sure how the OSDs would behave with the slow disks though, and the loss of storage efficiency might defeat the object.
Not saying it won’t work, just that I’ve never done it with SMR disks and I haven’t put an eyeball mark one on it.
Thanks for all the answers. I could bet I found a seagate datasheet which stated those are smr however I can’t find it now… They are for sure SED, so quite slow - I couldn’t care less about encryption on the drive but that’s what I got. I might just test the random write performance. Anyway the drive manufacture dates are between 19JUL2015 and 08AUG2015.
Clearing the keys might be a good idea however I’ve no clue how.
I think there are some instructions in that manual I linked. It’s probably tedious!
Might be worth looking through it to see if you can even disable the encryption. NB I am not sure that is possible, just an idea.
In theory SED wasn’t supposed to slow anything down, but every example I touched was slow as heck.
I never had one, but thought the idea of SED, is that you just throw away/regenerate keys instead of formatting/ erasing the drive?
If it is CMR, as it looks, I would say keep the SED if O/S supports it?
The drive is an older model anyway, 10% improvement would not make that much difference?
So I’ve found this cmr pdf and the nm0043 is not listed and so I thought it would be smr. As far as I can tell all cmr drives in the pdf end in 5.
That’s a modern datasheet, it’s not going to list the old drives.
I think you’ve got CMR.
Okay in that case I probably got ZFS. Since it’s free and performance is way better than unraid. But I’ll max out my capacity so I buy 5 additional cmr 3tb drives
Test performance with the nine you have first, and preferably with a ZIL on SSD.
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