System RAID Messages -- what do they mean?

Discussion in 'Technical' started by dpicella, Dec 24, 2012.

  1. dpicella

    dpicella New Member

    I recently set up a new server. The OS has 2 drives on RIAD 1 and the data has 3 disks on RAID 5. I got this message from the system. Not sure what it means. It is the only one a got and it has been several days, so maybe I can ignore it.

     
  2. falko

    falko Super Moderator

    What's the output of
    Code:
    cat /proc/mdstat
    ?
     
  3. dpicella

    dpicella New Member

    Personalities : [raid1] [raid6] [raid5] [raid4]
    md1 : active raid5 sdc1[0] sdd1[1] sde1[3]
    1953518592 blocks super 1.1 level 5, 512k chunk, algorithm 2 [3/3] [UUU]
    bitmap: 2/8 pages [8KB], 65536KB chunk

    md0 : active raid1 sdb1[1]
    312363900 blocks super 1.1 [2/1] [_U]
    bitmap: 3/3 pages [12KB], 65536KB chunk

    unused devices: <none>
     
  4. falko

    falko Super Moderator

    Your /dev/md0 array is degraded - /dev/sda1 is missing. Try to re-add it as follows:

    Code:
    mdadm --manage /dev/md0 --fail /dev/sda1
    mdadm --manage /dev/md0 --remove /dev/sda1
    mdadm --zero-superblock /dev/sda1
    mdadm -a /dev/md0 /dev/sda1
    (see http://www.howtoforge.com/how-to-se...ystem-incl-grub-configuration-debian-lenny-p4 ).
     
  5. dpicella

    dpicella New Member

    Weird ... Now I have 2 arrays that have degraded

    # cat /proc/mdstat

    Personalities : [raid1] [raid6] [raid5] [raid4]
    md1 : active raid5 sdd1[1] sde1[3]
    1953518592 blocks super 1.1 level 5, 512k chunk, algorithm 2 [3/2] [_UU]
    bitmap: 7/8 pages [28KB], 65536KB chunk

    md0 : active raid1 sdb1[1]
    312363900 blocks super 1.1 [2/1] [_U]
    bitmap: 3/3 pages [12KB], 65536KB chunk


    # fdisk -l

    Disk /dev/sda: 320.1 GB, 320072933376 bytes
    255 heads, 63 sectors/track, 38913 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes
    Disk identifier: 0x0005a631

    Device Boot Start End Blocks Id System
    /dev/sda1 * 1 26 204800 83 Linux
    Partition 1 does not end on cylinder boundary.
    /dev/sda2 26 38914 312365056 fd Linux raid autodetect

    Disk /dev/sdb: 320.1 GB, 320072933376 bytes
    255 heads, 63 sectors/track, 38913 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes
    Disk identifier: 0x000831b7

    Device Boot Start End Blocks Id System
    /dev/sdb1 1 38914 312569856 fd Linux raid autodetect

    Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
    255 heads, 63 sectors/track, 121601 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes
    Disk identifier: 0x00020849

    Device Boot Start End Blocks Id System
    /dev/sdc1 1 121602 976760832 fd Linux raid autodetect

    Disk /dev/sdd: 1000.2 GB, 1000204886016 bytes
    255 heads, 63 sectors/track, 121601 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes
    Disk identifier: 0x00031948

    Device Boot Start End Blocks Id System
    /dev/sdd1 1 121602 976760832 fd Linux raid autodetect

    Disk /dev/sde: 1000.2 GB, 1000204886016 bytes
    255 heads, 63 sectors/track, 121601 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes
    Disk identifier: 0x00059d1d

    Device Boot Start End Blocks Id System
    /dev/sde1 1 121602 976760832 fd Linux raid autodetect

    Disk /dev/md0: 319.9 GB, 319860633600 bytes
    2 heads, 4 sectors/track, 78090975 cylinders
    Units = cylinders of 8 * 512 = 4096 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes
    Disk identifier: 0x00000000


    Disk /dev/mapper/vg_localhost-lv_root: 262.1 GB, 262144000000 bytes
    255 heads, 63 sectors/track, 31870 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes
    Disk identifier: 0x00000000


    Disk /dev/mapper/vg_localhost-lv_swap: 8485 MB, 8485076992 bytes
    255 heads, 63 sectors/track, 1031 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes
    Disk identifier: 0x00000000


    Disk /dev/md1: 2000.4 GB, 2000403038208 bytes
    2 heads, 4 sectors/track, 488379648 cylinders
    Units = cylinders of 8 * 512 = 4096 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 524288 bytes / 1048576 bytes
    Disk identifier: 0x00000000


    Disk /dev/mapper/vg_localhost-lv_home: 49.2 GB, 49228546048 bytes
    255 heads, 63 sectors/track, 5985 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes
    Disk identifier: 0x00000000

    When I ran the fix from above I got this ...

    # mdadm --manage /dev/md0 --fail /dev/sda1
    mdadm: set device faulty failed for /dev/sda1: No such device

    # mdadm --manage /dev/md0 --remove /dev/sda1
    mdadm: hot remove failed for /dev/sda1: No such device or address

    # mdadm --zero-superblock /dev/sda1
    mdadm: Couldn't open /dev/sda1 for write - not zeroing

    # mdadm -a /dev/md0 /dev/sda1
    mdadm: Cannot open /dev/sda1: Device or resource busy
     
  6. falko

    falko Super Moderator

    Maybe one of your hard drives is dying...
     
  7. dpicella

    dpicella New Member

    It turned out to be loose cables. I was able to rebuild all the arrays!

    Personalities : [raid1] [raid6] [raid5] [raid4]
    md1 : active raid5 sdc1[0] sde1[3] sdd1[1]
    1953518592 blocks super 1.1 level 5, 512k chunk, algorithm 2 [3/3] [UUU]
    bitmap: 0/8 pages [0KB], 65536KB chunk

    md0 : active raid1 sda2[0] sdb1[1]
    312363900 blocks super 1.1 [2/2] [UU]
    bitmap: 0/3 pages [0KB], 65536KB chunk

    I found this to be helpful:
    http://www.zachburlingame.com/2011/05/howto-rebuild-a-software-raid-5-array-after-replacing-a-disk/

    I really like the last line that refreshes the progress!

    Cheers!
     

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