Administering RAID ArraysSetting Up the ftServer System 5-15Disk InsertionWhen you reinsert a pulled disk, the OSM storage plugin attempts to match it with anexisting disk. If it finds a match, it hot-adds the mirror partitions on the inserted diskback into the existing RAID arrays and resynchronizes them (see ‘‘Resynchronization’’on page 5-18).Similarly, if you replace a failed disk, the OSM plugin automatically adds thereplacement disk to a running RAID array.Administering RAID ArraysThis section discusses the following topics:• ‘‘To Stop a RAID Array and Move It to Another System”• ‘‘Errors and Faulty Mirrors”• ‘‘Removing a Faulty Mirror”• ‘‘Resynchronization”• ‘‘Replacing a Failed Disk”• ‘‘Manually Creating Partitions on Blank Disks and Adding to RAID-1 Arrays”You can use the mdadm command to administer RAID arrays. The following sectionsprovide examples of how to perform some common administrative procedures usingmdadm.N O T ENever remove both member disks of a RAID-1 array. TheLinux operating system does not support that operation.To Stop a RAID Array and Move It to Another SystemYou can stop RAID-0 and RAID-1 arrays, if they are not in use. Unmount the file system(if one is mounted) and stop the array as shown in the following example:# umount /dev/md30# mdadm -S /dev/md30Before physically removing the disks from the system, check that the RAID array nolonger appears in /proc/mdstat. Edit the /etc/fstab and /etc/mdadm.conffiles on the current system to delete it. Edit the information into the files in the newsystem. If the new system already has the device in use, you cannot start the RAIDarray.
