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I don't understand enough of the technical details in the article - can someone please explain what this means in practice? I use WD Reds in my Synology NAS in

I don't understand enough of the technical details in the article - can someone please explain what this means in practice? I use WD Reds in my Synology NAS in a SHR configuration for daily backups. Should I be worried? Should I replace the disks with other models? What are the risks if I keep the current configuration?

stingraycharles 7y ago
Essentially they’re selling disks as “raid compatible”. This implies the disk will perform well under constant pressure: resilvering a raid disk of these sizes can easily take several days. However, they have cut corners / optimized costs that assumes the drive is not under constant pressure, but rather mostly idle. What this implies is that they likely just have a hybrid magnetic/ssd backend, which is what the outrage is about.
- the8472 7y ago
  > What this implies is that they likely just have a hybrid magnetic/ssd backend No need for hybrids. DM-SMR drives usually have a non-SMR zone acting as a write buffer, similar to the SLC write buffers in non-SLC SSDs.
  - klodolph 7y ago
    Well, you’re right, but technically that makes it “hybrid SMR”.
notRobot 7y ago
This has been discussed a bit on r/DataHoarder, you might want to go read there.
- emilburzo 7y ago
  https://www.reddit.com/r/DataHoarder/comments/g1di7w/wd_admits_red_nas_drives_2tb6tb_are_smr/ https://www.reddit.com/r/DataHoarder/comments/g1di7w/wd_admi...
lxn 7y ago
If they worked so far, they will continue to work in the future. With my limited understanding, the new models will fail under intensive work-loads. For example adding them to existing RAID setups to replace a failed drive, where in the beginning they have to be sync-ed and they fail under load after a few hours (either by dropping in performance or not being recognized at all). They will work reasonable well under lower loads (more common for home NAS setups). The biggest problem, and what the article is trying to point out, is that Western Digital (and Seagate) are doing all they can to hide this info from customers. They even advertise the HDD as being NAS/RAID friendly, when they are clearly not meant for that type of loads.
cogman10 7y ago
Write performance (particularly random access writes) is degraded because of the way data is written to the disk. Unfortunately, the nature of RAID means that you can be dealing with a lot of random writes. Further, when a drive fails and you want to replace it, you are pushing massive amounts of writes to the new disk. A lot of this is due to the Shingling. Like shingles on your roof, the physical locations where data is written overlap. The problem is that if you need to update an already written location, you may also need to update surrounding bits. This is where the random write performance degradation comes from.
Crontab 7y ago
The site the article links to put up a companion article that explains the technology: https://blocksandfiles.com/2020/04/15/shingled-drives-have-non-shingled-zones-for-caching-writes/ https://blocksandfiles.com/2020/04/15/shingled-drives-have-n...
ComputerGuru 7y ago
It's not you, the article was written by someone that doesn't understand what they're trying to report on and is repeating facts they've been told are pertinent. Can't blame the reader for being confused.

stingraycharles 7y ago

Essentially they’re selling disks as “raid compatible”. This implies the disk will perform well under constant pressure: resilvering a raid disk of these sizes can easily take several days. However, they have cut corners / optimized costs that assumes the drive is not under constant pressure, but rather mostly idle. What this implies is that they likely just have a hybrid magnetic/ssd backend, which is what the outrage is about.

the8472 7y ago
> What this implies is that they likely just have a hybrid magnetic/ssd backend No need for hybrids. DM-SMR drives usually have a non-SMR zone acting as a write buffer, similar to the SLC write buffers in non-SLC SSDs.
- klodolph 7y ago
  Well, you’re right, but technically that makes it “hybrid SMR”.

notRobot 7y ago

This has been discussed a bit on r/DataHoarder, you might want to go read there.

emilburzo 7y ago
https://www.reddit.com/r/DataHoarder/comments/g1di7w/wd_admits_red_nas_drives_2tb6tb_are_smr/ https://www.reddit.com/r/DataHoarder/comments/g1di7w/wd_admi...

lxn 7y ago

If they worked so far, they will continue to work in the future. With my limited understanding, the new models will fail under intensive work-loads. For example adding them to existing RAID setups to replace a failed drive, where in the beginning they have to be sync-ed and they fail under load after a few hours (either by dropping in performance or not being recognized at all). They will work reasonable well under lower loads (more common for home NAS setups). The biggest problem, and what the article is trying to point out, is that Western Digital (and Seagate) are doing all they can to hide this info from customers. They even advertise the HDD as being NAS/RAID friendly, when they are clearly not meant for that type of loads.

cogman10 7y ago

Write performance (particularly random access writes) is degraded because of the way data is written to the disk. Unfortunately, the nature of RAID means that you can be dealing with a lot of random writes. Further, when a drive fails and you want to replace it, you are pushing massive amounts of writes to the new disk. A lot of this is due to the Shingling. Like shingles on your roof, the physical locations where data is written overlap. The problem is that if you need to update an already written location, you may also need to update surrounding bits. This is where the random write performance degradation comes from.

Crontab 7y ago

The site the article links to put up a companion article that explains the technology: https://blocksandfiles.com/2020/04/15/shingled-drives-have-non-shingled-zones-for-caching-writes/ https://blocksandfiles.com/2020/04/15/shingled-drives-have-n...

ComputerGuru 7y ago

It's not you, the article was written by someone that doesn't understand what they're trying to report on and is repeating facts they've been told are pertinent. Can't blame the reader for being confused.