CMR vs SMR for NAS

[Thorin]

So I'd kinda stopped paying attention to hardware news in the last five years or so. I totally missed the "WD sold SMR drives that people thought were CMR" debacle, and I also missed learning what the actual difference between CMR and SMR is and why it matters for a NAS.

So, had a short accidentally-self-inflicted power outage at my house (too many electric heaters on the same breaker) that also interrupted power to my main Drobo. When I powered the Drobo back up, one of the drives was marked bad and rejected, a 6TB WD Red Plus.

I went looking for a replacement and decided I should get two 8TB drives so I could increase my storage in both the main Drobo and the secondary Drobo a bit (add 2x8TB to the main to replace 2x6TB - adds 4TB; move 1x6TB to the secondary to replace 1x1TB - adds 5TB). Looking around on Black Friday I found 8TB WD Red Plus drives for $240 a piece. Then I found 8TB Seagate Barracuda drives for $150 a piece, huge savings!

They're both 5,400rpm drives, they're both 8TB, they're both 128MB cache, the Seagate is 2 year warranty while the WD is 3 year. That's all I need to know, right?

NO! I also had to know what CMR vs SMR is, and that the Seagate is SMR (which seriously, seriously hampers performance in a Drobo NAS) while the WD Red Plus is CMR (as opposed to the cheaper WD Red that is SMR).

.. sometimes I hate technology and technology companies ..

Anyway, I'm off to MemEx tonight to buy a couple of WD Red Plus 6TB that I have confirmed are CMR. I'm going with 6TB because it will still give me plenty of storage and they're $195 a piece instead of $240.

I'm hoping to be able to return those Seagates back to Amazon for a refund.

Oh, in case you care to know how it affects performance - after putting the Seagates with their SMR technology into the Drobo, now when I try to copy files to it the copying randomly pauses for seconds to minutes at a time, and it locks up the computer and I can't use Windows Explorer while it's locked up (but can still use a browser to visit web page to angrily google about potential causes for Windows Explorer locking up). This did not happen before I replaced the drives.

[Lazybones]

SMR are the fine and less expensive for any application that you don't have heavy write workloads. SMR is terrible in ANY RAID / striping config.

CRM (older tech) is the preferred option for NAS, and if you buy drives "branded" as NAS drives they will normally be CRM.

Note that Western Digital got in trouble for quietly introducing SMR into drive models and lines that previously didn't have them and that caused lots of issues for NAS users a few years ago.

Sucks.. SMR drives are not BAD, just not good for NAS setups with RAID.

[Thorin]

Thanks, that's a good summary of everything I learned yesterday. Luckily, I should be able to return them to Amazon, still have the original packaging as I've only had them a few days.

I felt pretty down on myself for not knowing this and potentially having wasted $315 on drives I couldn't use. Like, I try to know at least a little about everything, especially computer-related, but this just completely missed me until it affected me

[Melbosa]

How unfortunate, but hey everyone misses something here and there. You have to see it in your day job all over, bugs are the nature of this are they not?

I do hope you can return. Amazon hasn't shafted me yet on a return, so I hope you have a similar experience.

Seagate has a nice chart which I bet you found in your research, but for anyone else: https://www.seagate.com/ca/en/products/cmr-smr-list/ - I, like @Lazybones, stick to drives that are designed for NAS, so for me all mine are Seagate Ironwolf series in my Synology.

For my second tier, as I see you say you are still running two Drobos, I use Backblaze S3 as you can't beat S3 low cost storage pricing for TBs of storage.

[Lazybones]

I felt pretty down on myself for not knowing this and potentially having wasted $315 on drives I couldn't use. Like, I try to know at least a little about everything, especially computer-related

Well we are getting old. Things that worked one way do just suddenly change sometimes and we arn't in the loop. For decades you could just pick almost any
consumer drive and it would work because most of them had the same specs.

Modern drives are sold in various specs / price points.

Some are only intended for desktop / laptop use and to only spin a few hours per day and will wear out fast run 24/7 in a NAS. However unlike SMR drives these specs take longer to notice and for the most part are random in terms of impact.

Short answer is that a "NAS" drive will typically be designed for continuous use, heavy read / write and often have additional replacement / warranty coverage.  You can however check drive specs and get cheaper options.

Side note an often over looked spec is noise. There is a significant difference for various brands and models. Something to note if you are going to have a desktop NAS with drives run up all the time vs something in your basement / closet away from where you work.

[Thorin]

When I got my first Drobo in 2011, I bought 5x1TB WD Blacks for it, pretty expensive at the time but I still have three of them in use (one of which was replaced under warranty). At the time they were the only drives with 5-year warranties, so obviously well-engineered and -built.

Thanks for the suggestions, yes I'd found Seagate's CMR/SMR chart. I also figured out how to see CMR vs SMR for each specific WD drive. And I did also compare reported noise levels, although they all seemed pretty similar. I also have my Drobos set to spin down drives when they're not being actively used. The loudest part of each Drobo is actually the cooling fans, especially in the summer.

I use Backblaze to back up my documents, pictures, and stuff like that. I don't bother backing up movies or tv shows to the cloud, if I lose it I'll re-download it. How much do you pay? Backblaze's site says their Backblaze B2 (competitor to AWS S3) costs $6/TB/month, which would be $70/month for me, or $840 a year. Whereas I already own this other Drobo and have drives in it so that doesn't cost me anything anymore.

[Melbosa]

Last month was $23.05 for just over 2TB of backup - like you I don't backup my other stuff, just FP stuff I host and all  the pictures, home videos, and documents. And well the VMs that recreating would be a bit of a pain, like my plex server.

That $23.05/m is a year and a bit before it even covers the cost of 1 of my 12tb of storage onsite in my Synology. So figure its a good offsite tier.

[Lazybones]

And I did also compare reported noise levels, although they all seemed pretty similar. I also have my Drobos set to spin down drives when they're not being actively used. The loudest part of each Drobo is actually the cooling fans, especially in the summer.

decibel scale is logarithmic so keep in mind that that a difference of 10 dB is a 10X difference in loudness. 20-30 is like a whisper but 40 is like light rain / refrigerator running .

While most drives are in a similar 20-30 range you don't want to grab that one outlier with the 38 dB as you will notice the difference.

[Thorin]

So I went to MemEx on the west end today to buy my WD Red Plus drives. I stood in line for over 15 minutes, everyone in front of me needed explanations and hummed and hahhed and were doing the what-if-this game. Then when those people were finally done and paid, the sales associates walked away from their tills until there were only two left.

When it was finally my turn it took me 45 seconds to order and pay. I guess some people just haven't researched everything before they come in

There was one guy having a long conversation with a sales associate about chipsets and types of RAM and what to get and whether it's worth it to spend more now to be able to upgrade later. Like, the kind of discussion that normally happens back-and-forth on a tech-centric online message board.

Anyway, first of the new drives is in and it's re-balancing now, I should be able to swap the other drive by the end of the weekend.

[Mr. Analog]

This has been a very useful thread, the last drives I bought were in 2016 (8 WD Reds,) they're still holding strong but at some point I'll need more drive space so this is good to know

[Lazybones]

I am currently running 4 8TB IronWolfs and constantly need to free space.. I have also been considering an upgrade but have too many other things to improve at the moment.

[Thorin]

Here's what I'm running in my 5-bay NASes.

Drobo 5N2 (the newer one, used as my main NAS):

Name	Size	Cache	RPM	Model	Manufacture	Warranty
WD Red Plus	8TB	128MB	5600	WD80EFZZ	2023-11	3 years
Seagate	3TB	64MB	7200	ST3000DM001	2012-11	3 years
<empty>
WD Red Plus	8TB	128MB	5600	WD80EFZZ	2023-11	3 years
WD Black	6TB	256MB	7200	WD6003FZBX	2022-06	5 years

25TB (22.74TiB) total, 15.27TB (13.89TiB) usable after single-disk-failure redundancy

Drobo FS (the older one, used as a mirror in case the main one dies):

Name	Size	Cache	RPM	Model	Manufacture	Warranty
WD Black	5TB	128MB	7200	WD5001FZWX	2016-01	5 years
WD Black	5TB	128MB	7200	WD5001FZWX	2016-01	5 years
WD Red	6TB	256MB	5400	WD60EFAX	2019-07	3 years
WD Black	5TB	128MB	7200	WD5001FZWX	2016-01	5 years
WD Black	1TB	64MB	7200	WD1002FAEX	2011-06	5 years

22TB (20.01TiB) total, 14.48TB (13.17TiB) usable after single-disk-failure redundancy

• the WD Black 6TB (WD6003FZBX) in the newer Drobo is a replacement under warranty for a WD Red 6TB (WD60EFAX) that failed in less than three years; Western Digital didn't have any Reds available so sent me an as-good-or-better replacement (definitely better!)
• the WD Red 6TB (WD60EFAX) in the older Drobo is an SMR drive I didn't even realize it at the time
• lookit how long those Blacks have lasted! they've been in use this entire time!
• BeyondRAID (for Drobos) and SHR (for Synology) make such a difference, we can buy whatever drives and pop them in and not have to worry about getting the exact same drives for the entire RAID array, while still having enough protection that any one drive can fail without data loss
• quite the hodgepodge, eh?

[Mr. Analog]

Hahaha well it works though right? That's all that matters hahah

[Melbosa]

• BeyondRAID (for Drobos) and SHR (for Synology) make such a difference, we can buy whatever drives and pop them in and not have to worry about getting the exact same drives for the entire RAID array, while still having enough protection that any one drive can fail without data loss

Like my old Synology that had gone through many drives, I'd hate to see the raid partitions that were put together to handle those changes - mine went from 1TB x8 to (before I replace the whole thing) 10TB x8 with every jump inbetween (2TB, 4TB, 6TB, 8TB), and all at varying times (like at some point I had 4TB, 6TB and 8TB of various quantities in the synology).

Here is my current setup

Code Select Expand

Synology RS1221+

RAID: Synology Hybrid RAID (SHR) 1-Drive Fault Tolerance

Capacity: 52.6 / 76.3 TB Free

Drives:
* 7x 12TB Seagate Ironwolf
     Model: ST12000VN008
* 1x 12TB WD Red Plus
     Model: WD120EFBX


I am currently running 4 8TB IronWolfs and constantly need to free space.. I have also been considering an upgrade but have too many other things to improve at the moment.

Like this, I was too sick of running out of room, so why the crazy space I have now.