HDD over-provisioning in QuTShero ?

Questions about SNMP, Power, System, Logs, disk, & RAID.
Post Reply
ver2ual
Starting out
Posts: 14
Joined: Sun May 08, 2022 4:33 am

HDD over-provisioning in QuTShero ?

Post by ver2ual »

I cannot find a definitive answer as to whether over-provisioning is required or advised for HDD RAIDs (6) using QuTS hero- or not? I understand over-provisioning for SSD, but over-provisioning seems to be a default option when setting up HDD storage pools in QuTS hero, so I'm curious if this is related to ZFS?

Just for humor, the ZFS Profiling Tool estimated 80 days (not a typo) to complete the test for just 5% and 10% on the 7 drives I selected.

Thanks
TVS-672XT QTS 4.5.4: 6x10TB IronWolf RAID5 + 2x2TB Samsung 980 Pro M.2 RAID0
TVS-h1288X w/TB3 QuTS 5.0.0: 8x20TB IronWolf Pro RAID6 + 2x1TB Samsung 870 EVO RAID1 (OS) + 2x2TB Samsung 980 Pro M.2 RAID0
Kunzite
Know my way around
Posts: 243
Joined: Tue Jan 22, 2019 6:47 pm

Re: HDD over-provisioning in QuTShero ?

Post by Kunzite »

I'm watching this thread, because I have the exact same question.
I'm currently installing/configuring a TS-673A, with QuTS Hero. I've just ran the ZFS Pool Profiling Tool on the 2x1TB Samsung SSDs, it basically said "use 20% or greater" - but HDDs are obviously different. FTR, the profiling took quite a bit less than the estimation, about 5 hours rather than 19 - but once again, with HDDs things can be quite different.

My understanding is that some amount of over provisioning will help, particularly with ZFS' Copy-on-Write mechanisms, not to the same extent as with SSDs though (there's no write amplification with HDDs, right?); but I'm a strong believer in "measure, don't just believe". And I'm not actually sure... with HDDs, if the pool isn't anywhere near full, would there be any effect?
I'll try running the Profiling Tool myself, just not right now - I'm reusing the disks from the old NAS, and first I'd like to make sure all the backups are in order :) I'm using 4Tb WD Reds (CMR) so it should take days, not months. Would that be too late for you?

(I'm also tempted to just set some over provisioning, as I can later disable/reduce it)
ver2ual
Starting out
Posts: 14
Joined: Sun May 08, 2022 4:33 am

Re: HDD over-provisioning in QuTShero ?

Post by ver2ual »

I see the option to reduce or disable it after as well, so until I figure this out I chose 5%. Good to know about the "shorter than estimated" profiling tool. My 80-day estimate for 8 x 20TB drives made me chuckle.
TVS-672XT QTS 4.5.4: 6x10TB IronWolf RAID5 + 2x2TB Samsung 980 Pro M.2 RAID0
TVS-h1288X w/TB3 QuTS 5.0.0: 8x20TB IronWolf Pro RAID6 + 2x1TB Samsung 870 EVO RAID1 (OS) + 2x2TB Samsung 980 Pro M.2 RAID0
Kunzite
Know my way around
Posts: 243
Joined: Tue Jan 22, 2019 6:47 pm

Re: HDD over-provisioning in QuTShero ?

Post by Kunzite »

I'm running the test - with my 6 4TB HDDs in RAID6, it will take about 2 days in total; so this evening it should be complete. By the way, it won't show any (partial) results until the very end...
What I find a bit weird is that even the 20% test was interrupted early because "random write speeds were too low". But let's see the charts...
ver2ual
Starting out
Posts: 14
Joined: Sun May 08, 2022 4:33 am

Re: HDD over-provisioning in QuTShero ?

Post by ver2ual »

Pls post the results when you have them.
TVS-672XT QTS 4.5.4: 6x10TB IronWolf RAID5 + 2x2TB Samsung 980 Pro M.2 RAID0
TVS-h1288X w/TB3 QuTS 5.0.0: 8x20TB IronWolf Pro RAID6 + 2x1TB Samsung 870 EVO RAID1 (OS) + 2x2TB Samsung 980 Pro M.2 RAID0
Kunzite
Know my way around
Posts: 243
Joined: Tue Jan 22, 2019 6:47 pm

Re: HDD over-provisioning in QuTShero ?

Post by Kunzite »

I have the results, but... they're weird. According to these over-provisioning is hurting performance a lot, which doesn't make any sense to me. I'm suspecting a bug in the profiling tool - which, by the way, reported worse performance with higher over provisioning values for SSDs, too (temps being reasonable, so no throttling).
I'm attaching a screenshot where you can see what I mean. The small legend popup will tell you which color corresponds to which over-provisioning value (brown is 0%).
ZFS-profiling-hdd.jpg
Edit: I'm repeating the test with a single HDD, just to see if there's any difference. I should have the results tomorrow.
You do not have the required permissions to view the files attached to this post.
ver2ual
Starting out
Posts: 14
Joined: Sun May 08, 2022 4:33 am

Re: HDD over-provisioning in QuTShero ?

Post by ver2ual »

Hmm. This is even more puzzling now. I wish someone for QNAP would chime in. If you can take your results to QNAP and post their response that would be great. I'm not going to run the tool since I'm running 8x20TB RAID6 and don't want to run a test. Thanks for sharing.
TVS-672XT QTS 4.5.4: 6x10TB IronWolf RAID5 + 2x2TB Samsung 980 Pro M.2 RAID0
TVS-h1288X w/TB3 QuTS 5.0.0: 8x20TB IronWolf Pro RAID6 + 2x1TB Samsung 870 EVO RAID1 (OS) + 2x2TB Samsung 980 Pro M.2 RAID0
User avatar
dolbyman
Guru
Posts: 35024
Joined: Sat Feb 12, 2011 2:11 am
Location: Vancouver BC , Canada

Re: HDD over-provisioning in QuTShero ?

Post by dolbyman »

If you want QNAPs take on it, you need to contact QNAP (via ticket) .. they do not come here
Kunzite
Know my way around
Posts: 243
Joined: Tue Jan 22, 2019 6:47 pm

Re: HDD over-provisioning in QuTShero ?

Post by Kunzite »

dolbyman wrote: Sat May 28, 2022 12:48 am If you want QNAPs take on it, you need to contact QNAP (via ticket) .. they do not come here
Yeah... there's QNAPDanielFL, but he posts rarely (in his free time, it seems), and I think mostly in the Presales questions.
Speaking of him, I found some message on this subject, basically saying that OP should help even for HDDs: https://www.reddit.com/r/qnap/comments/ ... _for_hdds/
Kunzite
Know my way around
Posts: 243
Joined: Tue Jan 22, 2019 6:47 pm

Re: HDD over-provisioning in QuTShero ?

Post by Kunzite »

ver2ual wrote: Sat May 28, 2022 12:41 amIf you can take your results to QNAP and post their response that would be great. I'm not going to run the tool since I'm running 8x20TB RAID6 and don't want to run a test. Thanks for sharing.
Excellent idea, and I just did that. I'll post here when I get an answer.
It took me more than 2 days to run the test, with 6x4TB RAID6 (and the tests being terminated early because of "low performance"). If it was going to take weeks... nope, no chance (and I actually question the use of such a tool that would stress test your storage for weeks!).
Post Reply

Return to “System & Disk Volume Management”