[smegsicle]

write amplification. random writes can take, what twice as long?

wear leveling could mitigate, but the choices are somewhat limited:

NILFS seems to make assumptions based on SSDs, blowing up during its cleaning operation

btrfs or bcachefs could help, but who knows whats going on with those

[buran77]

WD mixed both CMR and SMR for the WD Purple, an a few other models too. The CMR wouldn't see any write amplification. But the SMR will suffer from all of the usual SMR limitations. Most importantly that it's only really useful with sequential writes, on top of the write amplification.

Actually the Purple only has one distinguishing characteristic. An ATA command to skip bad sectors instead of trying to read/write repeatedly. This is great for an NVR but it's not mandatory to use.

[scottlamb]

> WD mixed both CMR and SMR for the WD Purple, an a few other models too.

Could you point me at an example of a SMR-based WD Purple drive? Is this just a historical thing? As mentioned in my other comment, the spec sheets [1] say all (current) drives are CMR.

> Actually the Purple only has one distinguishing characteristic. An ATA command to skip bad sectors instead of trying to read/write repeatedly. This is great for an NVR but it's not mandatory to use.

I'd also be interested to see a reference / details for this.

[1] https://products.wdc.com/library/SpecSheet/ENG/product-brief... https://products.wdc.com/library/SpecSheet/ENG/product-brief...

[Dalewyn]

>WD mixed both CMR and SMR

I was a fan of WD HDDs before and I was in the market for some drives for my new NAS a few years ago. When I checked what drives were on the market, I saw WD doing that while Seagate still clearly marked which drives were which.

I swore off WD that day because my time is too valuable for their bullshit. I have no clue if they have amended their marketing, but I don't care since as far as I'm aware Seagate still clearly marks them and the drives I bought from them have all been fine. I'll likely buy Seagate again next time I'm in the market.

[snvzz]

>NILFS seems to make assumptions based on SSDs, blowing up during its cleaning operation

Wait what? Isn't NILFS designed for spinning rust?