I have two identical HDD in a linux software raid 1. I observed a mostly reading load on this raid device, with the process showing mostly iowait. iotop shows about 75% disk utilisation overall.
If I look now at the disk utilisations of the physical disks, one disk shows about 1M/s read, the other shows only 100K/s read. /proc/mdstat shows the array is in good health. What could be the issue that not both disks are used equally?
Regarding the comment: I tried both. Reading with two threads and with one. It doesn't change anything.