I am wondering are HSMR hard drive good for ReadyNas's ????
FWIW, the acronym is a bit ambiguous. HSMR often means "Host managed SMR", which definitely won't work in a ReadyNAS. But there are some references to "Hybrid SMR".
So I am curious about the model you are considering, and where you found it for purchase.
I'm not seeing a lot of info on how Hybrid SMR works, though what I am seeing suggested that there is a disk configuration tool that lets you choose to make some (or all) of the drive SMR. Likely the SMR portion is also host-managed, though the info I am seeing isn't clear on that. It appears targetted to large data centers, and allows them to set the drive up for SMR if they want to use the drive for cold storage (gaining 10% capacity in return for the inherently poor write performance of SMR).
I knew I should have asked first, but I purchase one to replace one of mine that failed, found it on Facebook brand new unopened $100 for a 18TB HSMR. I have all ready put it in my NAS and it seems to be working. Would it be okay or should I start looking for a replacement? When I talking to the guy I mentioned I might want more and he said if I purchased 5 he would sale them to me for $80 per 18TB drive.
but I purchase one to replace one of mine that failed, found it on Facebook brand new unopened $100 for a 18TB HSMR. I have all ready put it in my NAS and it seems to be working. Would it be okay or should I start looking for a replacement? When I talking to the guy I mentioned I might want more and he said if I purchased 5 he would sale them to me for $80 per 18TB drive.
I'm not seeing any info on this drive on Western Digital's website - the closest thing I see is the HC650, which is a host-managed SMR SAS drive (which won't work at all in a ReadyNAS). I suspect the drive you purchased isn't generally available to the public (if it was, the WDC website would list them). I have no idea on how well it will work (and is why I said I'd personally avoid HSMR).
The challenge with SMR technology is that sustained write speeds can be extremely slow. When you write to track X, the contents on track X+1 are also overwritten. So when doing a write to track X, track X+1 needs to be read first. After track X is written, track X+1 needs to be re-written.,so track X+2 needs to be read before that can be done. This "rippling" process continues until you reach the end of a zone - there is some extra space between zones, so the last track in the zone can be written without overwriting the data in the first track of the next zone.
"Host managed" SMR means that the server (in this case the NAS) needs to explicitly manage this write process in the device driver. ReadyNAS don't have a driver that will do that.
A "Disk Managed" SMR disk manages the writes itself in the disk firmware - generally with the help of a large cache, to minimize performance impact. Still, sustained writes will eventually overwhelm the cache, and when that happens the transfer speed drops to a crawl. So disk-managed SMR disks kind of work, but not well - some folks here have tried them with rather poor results - and some actually ended up losing their volume.
Without documentation, there's no easy way to tell if this is host-managed or not. Since it appears to work, it could be disk-managed. Or maybe the out-of-the box setup for this disk is pure CMR, with SMR being configured manually if you want that. Or maybe you just haven't tried to access data written to the SMR portion of the hybrid drive.
Okay I think I fallowed what you were saying, The one thing I went off of was if you look at the bottom of the drive it says
"Ultrastar Data Center Hard Drive"
High workload rating Delivering dependable performance to any storage environment, Ultrastar hard drives are designed with a workload rating1 up to 550TB per year, up to 10 times the rating for desktop drives. Ultrastar drives employ advanced technologies for enterprise-class reliability, power efficiency and performance.(https://www.westerndigital.com/en-ap/products/internal-drives/wd-ultrastar-sata-series-hdd#:~:text=D....)
