Question HDD TBW value?

[Red Squirrel]

I noticed some HDDs have a TBW rating, for example the 10TB WD red 7200 drive has a TBW rating of 180 TB. Is it just me or is that kinda low? Or am I interpreting that value wrong? From googling I kept getting stuff related to SSDs but from what I gather it's TB written per year. But assume I reach that, how many years does that give me? It's kind of unclear.

I always had the impression that HDDs had virtually unlimited writes provided there is no random mechanical failure so this is kind of a surprise to me to see such a rating on HDDs.

This is where I'm seeing that, but on other retailers too:

Western Digital Hard Drive WD101EFBX 10TB 3.5

WD Red Plus 10TB NAS Desktop Hard Disk Drive - SATA 6 Gb/s 256 MB Cache 3.5 Inch - WD101EFBX

www.canadacomputers.com

 

[Billy Tallis]

You can just refer to the manufacturer's specifications rather than trying to figure out how that data has been mangled by the reseller: https://www.westerndigital.com/tool...uct-brief-western-digital-wd-red-plus-hdd.pdf

180TB per year of powered-on time, reads plus writes, and the warranty is three years. Of course, this kind of metric is very rough, because workloads can vary quite a bit in how much IO is sequential vs random.

 

[Shmee]

From what I gather, that is 180 TB of activity per year, times 3 years, which makes your warranty good for 540 TB of activity? While I doubt you will exceed that value in 3 years, or even come close, it does seem a bit low, especially when compared to some SSD's TBW value, and the fact that this is true for a 14TB spinner!

I suppose you could look into NAS/enterprise drives that either don't have that figure in warranty terms, or have a higher rating, if needed.

 

[Red Squirrel]

Yeah that's what I think too, that is kinda low. With raid it will also have more writing going on with rebuilds and such. All the drives I have in service now are pushing 10 years and I can guarantee I've pushed PB worth of data on them in that time period. Is this just a result of having drives that are such high density now days? Maybe I should look at smaller drives like 6 or 8TB and just get more of them. Or maybe need to pay more and go enterprise.

 

[mindless1]

If you're getting 10 years, I'd just keep doing what you already are, except replace them more often. TBW limits for warranty (and marketing to sell more expensive HDDs) don't mean a lot for consumer applications.

Then again, a PB per drive in 10 years (avg. 286 GB/day) doesn't seem like a typical consumer application. Anything with that much I/O I'd do on SSDs and use the HDDs for final destination, bulk storage.

I'd guess my yearly avg. per HDD is under 20TB/year and the # wouldn't even be that high except in the last couple years I've done more re-encoding video. To save some thrashing of the HDD during re-encoding, I copy blocks (like 3 seasons of a TV show at a time) of files to SSD, re-encode to SSD, copy blocks back to HDD. Maybe it doesn't matter but it does make the re-encoding faster to not have concurrent I/O to a NAS HDD.

Smaller drives... guess it depends on how many volumes you want to juggle and how fast your data is expanding. In the past I tried to look at where the model considered was in TB/platter and avoided drives with more than 4 platters. I haven't kept up on where the WD Red Plus is on TB/platter but I'd guess around 2.something TB/per so that'd be 8TB to 10TB.

 

[Red Squirrel]

Yeah reading into this it looks like it's more of a warranty thing than endurance thing. I was thinking once you hit that much data written it's more likely to fail, but guess it just means they won't cover the warranty IF it fails. This comes up to about 20GB a day which is not really all that much for a raid array with VMs running on it as lot of IO will be taking place at all times, but if it's just a warranty thing then I'm not that worried. Most of my failures tend to happen way outside of warranty period or at very early in it's life.

I'm running out of disk space on all 3 of my arrays so this will be replacing the oldest which is a raid 5 with 9 1TB drives, then will shuffle some data around from the others to make it all work.

I'm short on cash these days and been holding out on this but think I will pull the trigger and see how it goes. I do need to start looking at upgrading the other drives anyway so maybe something I can do next year or something.

Edit: decided to pull the trigger. Got 8 of them. Wish me luck lol.