I have also been experiencing this slow parity checks for at least 6 months now.
When I start a parity check, I get anywhere from 95 MB/s to 115 MB/s for the first few minutes. Definitely not maxing out my controllers or each individual drive.
Based on my configuration I should be seeing speeds of 175 MB/s + at the bargaining since my slowest drive tops out at around 180 MB/s on average.
In the past on older versions I was definitely seeing much higher speeds at the beginning of the check even when I have some older slower drives in my array at the time (4TB maxing out at 145 - 150 MB/s).
[v6.8.x] Parity check slower than before in certain cases
in Stable Releases
Posted
I have also been experiencing this slow parity checks for at least 6 months now.
When I start a parity check, I get anywhere from 95 MB/s to 115 MB/s for the first few minutes. Definitely not maxing out my controllers or each individual drive.
Based on my configuration I should be seeing speeds of 175 MB/s + at the bargaining since my slowest drive tops out at around 180 MB/s on average.
In the past on older versions I was definitely seeing much higher speeds at the beginning of the check even when I have some older slower drives in my array at the time (4TB maxing out at 145 - 150 MB/s).
Here is my current drive configuration:
Also here is my parity check history:
Also attaching my diagnostics file.
ds1-diagnostics-20191210-1216.zip