Setting Up RAID ArraysSetting Up the ftServer System 5-13To stop the device, use the mdadm command with the -S argument, as follows:mdadm -S /dev/md30Creating and Mounting a File SystemThe RAID arrays created in the preceding examples are raw disk block devices. Youcan mount a file system on the RAID array.The following command creates an ext-3 journaled file system in the RAID-0 arraycreated above:# mkfs.ext3 /dev/md30You can mount the file system on a convenient mount point, /big_data, as follows:# mkdir /big_data# mount /dev/md30 /big_dataTo verify the work, use the command df to show the size of the file system:# df /big_dataUse the command ls to show the lost+found directory in the file system:# ls -l /big_dataAt this point, be sure to add the mount to the /etc/fstab file, so the file system ismounted during boot. Reboot the system to make sure it works.N O T EA single disk that is not part of a RAID array must have afile system mounted on it to ensure that its operation stateis reported correctly.Checking the Current State of RAIDThe mdstat file displays the current state of RAID. It shows all running RAID arraysand their current status, including which mirrors are present, whether they aresynchronized, and more. See Example 5-2.
