What do you think about buying second hand disks and using higher redundancy?
For example 4x 16TB in RAIDz2? Is anyone using something like that? How’s it performing, reliability-wise?
E: Thanks all for the opinions and information!
My current setup is eight 18TB Exos drives, all purchased from Amazon’s refurb shop, and running in a RAIDz2. I’m pulling about 450MB/s through various tests on a system that is in use. I’ve been running this about a year now and smartd hasn’t detected any issues. I have almost never run new drives for my storage and the only time I’ve ever lost data was back when I was running mdadm and a power glitch broke the sync on multiple drives so the array couldn’t be recovered. With zfs I have even run a RAID0 with five drives which saw multiple power incidents (before I got a redundant power supply) and I never once lost anything because of zfs’ awesome error detection.
So yes, used drives can be just fine as long as you do your research on the drive models, have a very solid power supply, and are configured for hot-swapping so you can replace a drive when they fail. Of course that’s solid advice even for brand new drives, but my last set of used drives (also from ebay) lasted about a decade before it was time to upgrade. Sure, individual drives took a dump over that time, this was another set of eight and I replaced three of them, but the data was always safe.
I got the same setup with eight 18TB Exos drives running in a RAIDz2 with an extra spare. Added to this though I got another vdev of eight 12 WD reds with another spare.
With this I can have 2 drives fail in a vdev at any point and still rebuild the pool. Though if more than 2 drives all fail at the same time the whole pool is gone.
But if that happens I have a second NAS offsite at my bro’s place that I backup specific datasets. This is connected with tailscale and a zfs replication task.
I dunno, like I said zfs is pretty damn good at recovery. If the drives simply drop out but there’s no hardware fault you should be able to clear the errors and bring the pool back up again. And the chances of two drives failing at the same time are pretty low. One of these days I do need to buy a spare to have on hand though. Maybe I’ll even swap out one drive just to see how long it takes to rebuild.
Do it. The last thing you need during a rebuild is the stress of not knowing how long / other issues with your specific setup.
It’s only "disaster recovery* if you’ve never practiced… orherwise it’s just “recovery”
It all depends on how safe you want your data to be.
Second Hard drives should be fine with enough redundancy.
I’d rather run 2 secondhand drives in Raid 1 than a single new drive.
I would check out serverpartdeals as they’re pretty reputable. But for any used drive, I would make sure that you have a limited warranty or at least some sort of return policy. Once you get the drive, run badblocks on it, which will check for… bad blocks.
Hot damn these are cheap!
For $600 I could get 32TB array in:
- 4x 16TB manufacturer recertified, 2-disk redundancy
- 3x 16TB new, from interesting sellers, 1-disk redundancy
A 1-disk redundancy 32TB array sold from Newegg would be closer to $900. I could get 3-disk redundancy 32TB array from these guys for that much. 🤔🤔🤔
I’ve had great experiences with exactly one vendor of second hand disks.
Currently running 8x14TB in a striped & mirrored zpool.
I wish this was an option for Europe. Once you slap VAT and shipping, you end up paying more than for new disks. :(
For hard drives I’d never trust them used with data I care about. Especially big drives like that that would take AGES to rebuild.
For enterprise grade SSDs I’d kinda yolo it for a system I care a bit less for, or as a cache drive. But not HDDs.
What if you can do a 2 or 3 disk redundancy?
In my experience both new and used drives either fail within the first few weeks or they go on foreverrrrr…
Make sure there is a warranty/decent return policy and test obviously as others have said…but I’ve bought more 3 and 4TB HGST drives than I care to admit and have very rarely had any issues. At the price you can find even larger TB sizes for I personally consider it worth the gamble for certain use cases.
Like everyone else I’d be skeptical of used disks. I’d also go for a larger array than 4 drives to have less of it redundant. Like 6+2 or 5+3 instead of 2+2.