On 16/01/2019 18:33, Götz Reinicke wrote:
My question is: How are your experiences with the current >=8TB SATA disks are some very bad models out there which I should avoid?
Be careful with Seagate consumer SATA drives. They are now shipping SMR drives without mentioning that fact anywhere in the documentation. One example of such a model is the 4TB ST4000DM004 (previous models like the ST4000DM000 were not SMR). I expect this to cause catastrophically slow performance under heavy write volumes, e.g. when rebuilding or rebalancing PGs.
I assume enterprise models are fine (if you read the fine print), but I would avoid any current generation Seagate consumer models unless you're happy buying a sample first and benchmarking it to confirm what kind of drive it is, or you can find someone who has done so. SMR drives have a telltale sign of unreasonably fast random write performance for a brief time (well beyond practical IOPS for any normal HDD), which then craters to nearly zero once the internal journal fills up.
Personally I'm using MD05ACA800 (8TB toshiba, spec unknown, seems to be a B2B model but they're available for cheap) and they seem to work well so far in my home cluster, but I haven't finished setting things up yet. Those are definitely not SMR.
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