Managing an MD Device

Viewing the Status of the MD DeviceViewing the Status of the MD Device

After creating an MD device, you can view its status. By doing so, you can remain informed of whether the device is clean, up and running, or if there are any errors.

To view the status of the MD device, run the following command on any node:

cat /proc/mdstat

Immediately after the MD devices are created and during some recovery processes, the devices undergo a re-mirroring process. You can view the progress of this process in the /proc/mdstat file. Following is the output you will see:

[root@dlhct1 ~]# cat /proc/mdstat Personalities : [raid1]

md0 : active raid1 sde[2] sdf[0] 9766784 blocks [2/1] [U_]

[=>...................] recovery = 8.9% (871232/9766784) finish=2.7min

speed=54452K/sec unused devices: <none>

NOTE

A status report obtained using the cat /proc/mdstat command shows

 

the MD device name and the actual device names of the two MD

 

component devices. It does not show the persistent device names.

 

After you create an MD device, you can view the status of the device, stop

 

 

and start the device, add and remove a mirror component from the MD

 

device.

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Appendix A