I updated my backup server this weekend from CentOS 7 to CentOS 8.
OS disk is SSD, /dev/md0 are two 4TB WD mechanical drives.
No hardware was changed.
1. wiped all drives
2. installed new copy of 8 on system SSD
3. re-created the 4TB mirror /dev/md0 with the same WD mechanical drives
4. created the largest single partition possible on /dev/md0 and formatted
it ext4
5. waited several hours for the creation of /dev/md0 to finish
6. copied all data back onto /dev/md0
Both installs were a full workstation, with Gnome.
The mirror is mounted via fstab as:
/dev/md0 /mnt/raid1 ext4 defaults 0 0
Under CentOS 7 the /dev/md0 mirror was silent when not in use. Now under
8, the hard drives are constantly "pinged" by some process, at about the
same frequency as a heartbeat monitor. I can not figure out what process
is keeping them active. iotop does show a process named [ext4lazyinput].
Is there something I've missed?