On Thu, Jan 02, 2025 at 06:29:08PM +1100, George at Clug wrote:
I once used/tested with RAID 6 and was amazed how long it took to rebuild a 3TB swapped hard drive (about 8 hours, if I recall).
Spinning disks are slow; 8 hours for 3TB is about 100MB/s and 8h is about how much time I'd expect it to take to write a commodity disk that size. It becomes really painful on a 24TB drive (8 times as large, 8 times as long; a fast spinning disk might be able to cut that down to a full day). If you want significant speed increases you need an nvme drive--but beware: there's a default rate-limit to minimize impact to other work. (see /proc/sys/dev/raid/speed_limit_max, probably 200MB/s, and you'd want to set it much higher to fully utilize nvme storage.)
