Raid Software (MDx)

    Note: If you've problem like ERROR: sector 0. You could use --force option.

    Global overview (info)

    cat /proc/mdstat

    Detailed information

    mdadm --misc --detail /dev/mdx

    Create a new raid (drives and/or partitions)

    mdadm --create /dev/mdx --level=1 --raid-devices=2 /dev/sdaX /dev/sdbX

    Add a drive to an existing raid

    mdadm /dev/mdx --manage --add /dev/sdbx

    Declare an array as failed

    mdadm --fail /dev/mdx /dev/sdax


    Copy partitions (identical partitions)

    Especially useful if you've changed a drive (e.g. broken), or if you badly manipulate a disk. Let say it happens on /dev/sda:

    # if MBR
    sfdisk -d /dev/sdb | sfdisk /dev/sda
    # elif GPT (-R for replicate)
    sgdisk -R=/dev/sda /dev/sdb

    Remove raid partitions

    umount -l /dev/mdX
    mdadm --stop /dev/mdX
    mdadm --zero-superblock /dev/sdaX
    mdadm --zero-superblock /dev/sdbX ... etc.


    Resync is pending

    Might happened if you reboot during a sync, the following command will continue the sync:

    mdadm --readwrite /dev/mdx