Facebook Twitter Instagram
    TecAdmin
    • Home
    • Ubuntu 20.04
      • Upgrade Ubuntu
      • Install Java
      • Install Node.js
      • Install Docker
      • Install LAMP Stack
    • Tutorials
      • AWS
      • Shell Scripting
      • Docker
      • Git
      • MongoDB
    • FeedBack
    • Submit Article
    • About Us
    Facebook Twitter Instagram
    TecAdmin
    Home»RAID-ARRAY»How to Replace Faulty Device from RAID Array

    How to Replace Faulty Device from RAID Array

    RahulBy RahulApril 13, 20144 Mins Read

    In the previous article we describe to how to Setup RAID-1 in RHEL/CentOS systems. Some times disks attached with the array get failed working, RAID simply mark it as faulty device and do not use it any more. In that situation we need to replace the faulty device with new working device. The below image is showing that /dev/sdc1 disk has been marked as faulty and new disk attached has taken place of that with complete data sync.

    Raid-1-Array-with-Faulty-Disk

    In this article you will get to how to check which device is faulty and how to remove them from raid array. This article will step by step help you to How to Replace Faulty Device from RAID Array.

    Step 1: Identify Faulty Device

    Its importent to identify the correct disk which is marked a faulty by raid, use mdadm –status to check status of all disks attached in RAID.

    [[email protected] ~]# mdadm --detail /dev/md0
    
    /dev/md0:
            Version : 1.2
      Creation Time : Tue Mar 25 19:30:56 2014
         Raid Level : raid1
         Array Size : 5252187 (5.01 GiB 5.38 GB)
      Used Dev Size : 5252187 (5.01 GiB 5.38 GB)
       Raid Devices : 2
      Total Devices : 2
        Persistence : Superblock is persistent
    
        Update Time : Tue Mar 25 22:40:08 2014
              State : clean, degraded
     Active Devices : 1
    Working Devices : 1
     Failed Devices : 1
      Spare Devices : 0
    
               Name : server1:0  (local to host server1)
               UUID : 32a1c5ed:7d6a99a6:29d422f9:a3559b48
             Events : 18
    
        Number   Major   Minor   RaidDevice State
           0       8       17        0      active sync   /dev/sdb1
           1       0        0        1      removed
    
           1       8       33        -      faulty spare   /dev/sdc1
    
    

    If you looks the above output, the disk /dev/sdc1 is showing faulty and added as spare disk. So our target it to remove /dev/sdc1 and add a new disk in place of that. Also make sure to set file system type as Linux raid autodetect.

    For Learning Purpose Only: You can simply mark any disk as faulty using following command

    [[email protected] ~]# mdadm /dev/md0 --fail /dev/sdc1
    
    mdadm: set /dev/sdc1 faulty in /dev/md0
    

    Step 2: Create New Disk

    I have attached a new virtual disk /dev/sdd in system. Lets make a partition on disk as /dev/sdd1 of same size of faulty disk.

    [[email protected] ~]# fdisk /dev/sdd
    
    Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
    Building a new DOS disklabel with disk identifier 0xe70cdc62.
    Changes will remain in memory only, until you decide to write them.
    After that, of course, the previous content won't be recoverable.
    
    Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
    
    WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
             switch off the mode (command 'c') and change display units to
             sectors (command 'u').
    
    Command (m for help): n
    Command action
       e   extended
       p   primary partition (1-4)
    p
    Partition number (1-4): 1
    First cylinder (1-1305, default 1):
    Using default value 1
    Last cylinder, +cylinders or +size{K,M,G} (1-1305, default 1305): +5G
    
    Command (m for help): t
    Selected partition 1
    Hex code (type L to list codes): fd
    Changed system type of partition 1 to fd (Linux raid autodetect)
    
    Command (m for help): w
    The partition table has been altered!
    
    Calling ioctl() to re-read partition table.
    Syncing disks.
    

    Step 3: Remove Faulty Disk on RAID

    Lets remove faulty disk from RAID array

    [[email protected] ~]# mdadm /dev/md0 --remove /dev/sdc1
    
    mdadm: hot removed /dev/sdc1 from /dev/md0
    

    Step 4: Attach New Disk in RAID

    As we have removed faulty disk from RAID array, Lets attach new disk /dev/sdd1 in place of that.

    [[email protected] ~]# mdadm /dev/md0 --add /dev/sdd1
    
    mdadm: added /dev/sdd1
    

    As soon new disk attached to RAID array, it will automatically start syncing data to disk, To view status of sync use

    [[email protected] ~]# cat /proc/mdstat
    
    Personalities : [raid1]
    md0 : active raid1 sdd1[2] sdb1[0]
          5252187 blocks super 1.2 [2/1] [U_]
          [====>................]  recovery = 22.8% (1200000/5252187) finish=0.2min speed=240000K/sec
    
    unused devices: 
    
    faulty disk mdadm mirroring raid raid-1 raid1
    Share. Facebook Twitter Pinterest LinkedIn Tumblr Email WhatsApp
    Previous ArticleHow to Setup RAID-1 Array using Two Virtual Disks in CentOS/RHEL 6
    Next Article Bash – Test if file or directory exists

    Related Posts

    What is RAID Storage Technology

    Updated:March 26, 20173 Mins Read

    How to Increase Speed of Software RAID Rebuilding in Linux

    3 Mins Read

    How to Setup RAID-1 Array using Two Virtual Disks in CentOS/RHEL 6

    5 Mins Read

    Leave A Reply Cancel Reply

    Recent Posts
    • How to Enable / disable Firewall in Windows
    • How to Install JAVA on Ubuntu 22.04
    • Switching Display Manager in Ubuntu – GDM, LightDM & SDDM
    • Changing the Login Screen Background in Ubuntu 22.04 & 20.04
    • How To Install PHP (8.1, 7.4 or 5.6) on Ubuntu 22.04
    Facebook Twitter Instagram Pinterest
    © 2022 Tecadmin.net. All Rights Reserved | Terms  | Privacy Policy

    Type above and press Enter to search. Press Esc to cancel.