If you want to manually start or stop a RAID consistency check in Linux it’s quite simple.
Starting a check on md0:
root@desktop:~# echo check > /sys/block/md0/md/sync_action
Stopping a check on md0:
root@desktop:~# echo idle > /sys/block/md0/md/sync_action
If you’re using Debian (or a Debian based distro, e.g. Ubuntu), there is a script to do this.
Just a real quick post on how to get progress updates from dd.
The dd command normally doesn’t display any progress updates when you run it.
In order to get dd to print out its current progress, send the USR1 signal to the dd process.
Step 1: Start dd.
username@desktop:~$ dd if=/dev/random of=outfile
Step 2: Get the PID (Process ID) of dd.
username@desktop:~$ ps a PID TTY STAT TIME COMMAND -- snip -- 9158 pts/30 S+ 0:00 dd if=/dev/random of=outfile 9187 pts/31 R+ 0:00 ps a