SATA HDD Deals on ebay, do you still consider whether HDD made for NAS, desktop, Archive?

[Markess]

Hi. I'm preparing myself just in case there's a good deal that appears online (ebay). When you buy drives for NAS use, do you consider whether the model of the drive was designed for NAS, desktop, or archival purposes? Or do you just consider cost per TB? I am using Unraid btw.

Do you think the Desktop models, when used in a NAS environment used at home, will die quicker the the Enterprise models?

You mentioned you're using Unraid. While the comments above about SAS drives being able to spindown/standby are correct, you should be aware (if you aren't already) that SAS spindown isn't supported by Unraid itself. The developers have stated multiple times that SAS support isn't a priority for them, and its not on the roadmap. At least not the last time I checked

There is a community plug-in for SAS spindown that got released last fall, but the early adopters have had issues with some drives/controllers. If you do consider SAS drives, you may want to take a look at which ones have known issues when using Unraid:

[Plugin] Spin Down SAS Drives

 

[jang430]

@Markess , hence my Title "SATA HDD Deals on ebay, do you still consider whether HDD made for NAS, desktop, Archive?"

I'm not considering SAS.

 

[Markess]

@Markess , hence my Title "SATA HDD Deals on ebay, do you still consider whether HDD made for NAS, desktop, Archive?"

I'm not considering SAS.

Good call. I just didn't want all that talk about how great a value SAS drives were to change your mind. And honestly, gently used SAS drives are a great value...if you don't want to spindown in Unraid.

As for your question: when you put suspending your drives into the question, there's folks that think the reliability question shifts from MTBF Hours, annual throughput, and other "more traditional" HDD reliability ratings, to a drive's rating for Load/Unload Cycles. Spinning a drive up and down isn't as hard on hardware as it used to be, but it still adds to wear and tear in ways that simply letting them spin doesn't. Looking at Load/Unload cycles, a lot of the Consumer/Prosumer "NAS" drives stack up similarly to Enterprise/Data Center lines while costing significantly less. An example with Western Digital Corp. 4TB CMR Drives (what I currently use in my NAS):

• Blue (WD40EZRZ) rated for 300K load/unload cycles (no MTBF listed in the datasheet)
• Red Plus (WD40EFZX) rated for 600K load/unload cycles with 1M hours MTBF
• Ultrastar (Hitachi) DC HC300 also rated for 600K load/unload cycles but 2M hours MTBF

So with the Data Center drive, which costs a lot more, Western Digital Corp isn't claiming any more reliability for going into or out of standby. Instead they offer more annual/lifetime writes and run time.

In my case, my drives never write hundreds of gigabytes a day. And since they spend much of their lives on standby, it will be a LONG time before they reach 2 Million hours of run time. But they do spin up and down a lot. So, load/unload became a more pressing concern. You'd be surprised how often your drives are spinning up and down even if you aren't accessing them, especially if you have particularly invasive SMART checks set up.

For me, since Red Plus didn't cost a lot more than Blue, and WD thinks it can take twice the starts/stops, the Red Plus was the better choice. Ultrastar was a pretty significant premium though, with the same Start/Stop reliability. So, for me Red Plus (formerly just "Red" before the SMR thing) was the sweet spot.

Just one example, and the value equation may differ with Seagate and others. YMMV.

 

[jang430]

@Markess , thank you for the explanation. This load/ unload thing gives me some new metric to look out for when buying my next drives. It will be quite a while I hope, cause I just bought myself 4 Seagate Exos Sata 8 TB, 7200 RPM, ST8000NM0055! . I remember seeing this model is CMR. Now I have to check it's load/ unload cycles and MTBF

Hope I made the right choice.

I have my old bunch of Seagate 2 TB Desktop models from Seagate running for about 3 years with spindown enabled. I'm lucky, so far, nothing happened with all 6 of them. Having said that, I wonder how many Unraid users do spin down their SATA drives. Or could it be, most of them are using SAS drives?

 

[Markess]

I have my old bunch of Seagate 2 TB Desktop models from Seagate running for about 3 years with spindown enabled. I'm lucky, so far, nothing happened with all 6 of them. Having said that, I wonder how many Unraid users do spin down their SATA drives. Or could it be, most of them are using SAS drives?

Load/Unload is a standard SMART attribute, so you can track it that way. If you are making use of standby, its helpful to keep an eye out on the attribute with new drives anyway to make sure there's nothing in your config that's spinning drives up frequently when there's no read/write requests.

One of the reasons that the Unraid developers aren't rushing to include SAS support is their focus on non-enterprise customers. So, I think there's more SATA users than SAS ones. That said, there's a couple Unraid "Power Users" here on the forums that use SAS drives....lots of SAS drives...that are on 24/7.

 

[jang430]

Load/Unload is a standard SMART attribute, so you can track it that way. If you are making use of standby, its helpful to keep an eye out on the attribute with new drives anyway to make sure there's nothing in your config that's spinning drives up frequently when there's no read/write requests.

One of the reasons that the Unraid developers aren't rushing to include SAS support is their focus on non-enterprise customers. So, I think there's more SATA users than SAS ones. That said, there's a couple Unraid "Power Users" here on the forums that use SAS drives....lots of SAS drives...that are on 24/7.

Yup. Even I was so tempted to get my hands on SAS drives. Enterprise, and cheap . I always had this notion that spin down will save me a lot of electricity. I tested it right now with 7 drives spun down, and turned it all up. wattage used increased by 50 watts. If there are plenty of drives, it may be significant.