Page Comparison

Step-by-step guide

1. Check devices installed using 'fdisk -l'
   You can also use 'df -h' to view list of devices in MB/GB's 
   

   #Example: 
   
   [root@admin]# fdisk -l

    Device   Boot       Start       End           Blocks   Id   System

   /dev/sda1      *               1         20         153600   83   Linux
   /dev/sda2                    20   36990   296960000   83   Linux
   /dev/sda3              36990   52287   122880000   83   Linux
   /dev/sda4              52287   91202   312579072     5   Extended
   /dev/sda5              52288   65036   102400000    83  Linux
   /dev/sda6              65036   66311     10240000    82  Linux swap / Solaris
   /dev/sda7              66311   91202   199936000    83  Linux

    

   
   

2. Check to make sure the device you use is properly partitioned for the RAID array you plan on adding it to
    

3. Check your current RAID configuration using '/proc/mdstat' to ensure you know which RAID array you are targeting

   Example:
   [root@admin]# root@admin:~$ cat /proc/mdstat
Personalities 


   Personalities :

    [raid1]

    [raid6]

    [raid5]

    [raid4]

   md1 

   
   md1 :

   active

   raid1

   sdb2[1]

   sda2[0]

   136448 blocks

   
            136448 blocks [2/2]

    [UU]

   md2 

   
   
   md2 :

   active

   raid1

   sdb3[1]

   sda3

   ada3[0]

   129596288 blocks

   
               129596288 blocks [2/2]

   [UU]

   md3 

   
   
   md3 :

   active

   raid5

   sdl1

   adl1[9]

   sdk1[8]

   sdj1

   [7] sdi1

   [6]

   sdh1[5]

   sdg1[4]

   sdf1[3]

   sde1[2]

   sdd1

   sdd[1]

   sdc1

   sdc[0]

   1318680576 blocks level 5, 1024k chunk, algorithm 2

   
               1318680576 blocks level 5, 1024k chunk, algorithm 2 [10/10]

    [UUUUUUUUUU]

   md0 

   
   
   md0 :

   active

   raid1

   sdb1

   sdb[1]

   sda1

   sda[0]

   16787776 blocks

   
               167877736 blocks [2/2]

    [UU]

   
   
   unused

   devices:

   <none>

4. Add device to RAID array using 'sudo mdadm --manage /dev/md# --add /dev/sdx#'
   

   Example

   #Example:
   

   [

   
   root@admin

   ]#

   :~$ sudo mdadm --manage /dev/md1 --add /dev/sda3

    

   
   

5. Check status in '/proc/mdstat'

   Example

   #Example:
   

   Personalities 

   
   Personalities :

    [raid1]

    [raid6]

    [raid5]

    [raid4]

   md127 

   
   md127 :

   active

   raid5

   sdh1[6]

   sdg1[4]

   sdf1[3]

   sde1

   sdeq[2]

   sdd1[1]

   sdc1[0]

   1464725760 blocks level 5, 64k chunk, algorithm 2

   
               1464725760 blocks level 5, 64k chunk, algorithm 2 [6/5]

    [UUUUU_]

   
               [===>.................]

   recovery

    recovery =

   14.2%

   (41598211/292945152)

   finish=125.5min

   speed=33440K/sec 

   
   

...