mdadm
CautionSoftware RAID (md)
mdadm --detail /dev/md0
Manages md RAID. [U_] in /proc/mdstat reveals a missing member; swap disks with --fail/--remove/--add.
Examples
cat /proc/mdstatRAID health at a glance
Syntax
mdadm --detail <md> / cat /proc/mdstat
Before you run it
Triple-check device names during swaps.
The same reference, with no signal at all
Every command and flow from this site, held on your device and searchable with no connection. Free to install, no ads.
Get it free on the App Store