Been using Debian on my Plex server for a while. Whenever I add drives to expand the array, disk I/O takes a nose dive as MDADM eats up everything and Plex struggles to stream a single show. I don't know enough about Linux (or MDADM) to issue commands that instruct it to yield disk I/O to programs like Plex or my FTP server when it's doing a resilver.
I -LOVE- how flexible MDADM is because in the couple of years I've been using it, I had to pull all the drives out and move them to another box 2 times. Each time, MDADM saw the array and happily imported it and away it went. I know that with hardware RAID cards, there's the potential problem of buying a new replacement card and it not being able to import your existing array due to a BIOS mismatch or something else.
Since I'm not a fan of ZFS, and worry a TINY TINY bit about bit-rot, I like how hardware cards will look at data on the drive (and the parity bits) and if data set 1 and parity match but data set 2 doesn't match, data set 2 will be fixed. With MDADM, it assumes the data bits are always correct and recalculate the parity if something doesn't line up.
TLDR: Currently, when I add 2, 4TB drives to my existing array, MDADM takes about 18 hours to reshape. I've always wondered if using a dedicated hardware RAID card would cut that time in half so I'm just looking for benchmarks of MDADM vs a hardware card while reshaping an array.
EDIT: My CPU is an i7 7700K and all hard drives are WD Red 4TBs sitting in a Super Micro 846 chassis.
Thanks
I -LOVE- how flexible MDADM is because in the couple of years I've been using it, I had to pull all the drives out and move them to another box 2 times. Each time, MDADM saw the array and happily imported it and away it went. I know that with hardware RAID cards, there's the potential problem of buying a new replacement card and it not being able to import your existing array due to a BIOS mismatch or something else.
Since I'm not a fan of ZFS, and worry a TINY TINY bit about bit-rot, I like how hardware cards will look at data on the drive (and the parity bits) and if data set 1 and parity match but data set 2 doesn't match, data set 2 will be fixed. With MDADM, it assumes the data bits are always correct and recalculate the parity if something doesn't line up.
TLDR: Currently, when I add 2, 4TB drives to my existing array, MDADM takes about 18 hours to reshape. I've always wondered if using a dedicated hardware RAID card would cut that time in half so I'm just looking for benchmarks of MDADM vs a hardware card while reshaping an array.
EDIT: My CPU is an i7 7700K and all hard drives are WD Red 4TBs sitting in a Super Micro 846 chassis.
Thanks