Hiya, so am looking to buy more storage and while browsing am seeing some external harddisks, such as Western Digital My Book and Seagate Expansion Desktop for cheaper than the internal harddisks themselves. Have seen this one video from KTZ Systems where he bought up multiple of these external ones just to open them up and use the disks for his own server. Was therefore wondering if you peeps have ever done this and if there any downsides to it at all?
You might want to look up SMR vs CMR, and why it matters for NASes. The gist is that cheaper drives are SMR, which work fine mostly, but can time out during certain operations, like a ZFS rebuild after a drive failure.
Sorry don’t remember the details, just the conclusion that’s it’s safer to stay away from SMR for any kind of software RAID
EDIT: also, there was the SMR scandal a few years ago where WD quietly changed their bigger volume WD Red (“NAS”) drives to SMR without mentioning it anywhere in the speccs. Obviously a lot of people were not happy to find that their “NAS” branded hard drives were made with a technology that was not suitable for NAS workload. From memory i think it was discovered when someone investigated why their ZFS rebuild kept failing on their new drive.
i bought a few smr drives, knowing they were smr. they were cheaper, a lot cheaper than the same amount of space in cmr. used only for static media storage, so that’s not a big deal, really., but holy hell was it slow getting stuff on them initially.
i have a few self-powered externals that are also smr (quite common with those as they use 2.5in notebook hdd). when those things have to start shuffling bits around and rewriting tracks, sustained write speeds fall well under what even usb2 can send.
Pretty sure my Seagate usb disks I use for backup are SMR and sustained writes are awfully slow. Luckily I’ve discovered restic for backing up which lowered a 1.5tb weekly incremental backup from 9hrs to 1 min.