MD34xx / MD38xx How to replace a physical drive in predictive failure / impending failure

 

 

 
This tutorial explains how to replace a disk in predictive or impending failure. A disk is always a bit bigger than specified because it has space to relocate bad blocks. It is allowed to have a couple of read/write errors, but if a threshold is reached, the controller will change the status of the disk to "predictive failure" because the relocation table is full.

The disk will continue to work but the probability that the HDD fails sonly is high. As this disk is still working and fully part of the RAID, the disk has to be put offline before replacement. This tutorial will guide you to put offline the hard disk

 

Prerequisite:

Modular Disk Storage Software (MDSM) has to be installed for this procedure. The computer must be able to access to the storage array.

 

Steps:

Launch MDSM. If you have several PowerVault arrays, select the one of your choice.
 
Make sure that its state is "Optimal" (see image below).


Figure 1: MDSM Device view showing optimal state



Double click on the array to access to the matrix manager.
Click on Hardware and then select the disk to be put off-line.


Figure 2: MDSM Hardware view


Do a right click and select Advanced, then Fail.


Figure 3: MDSM Hardware menu showing where to manually fail a drive


To validate the operation, a menu asking you to confirm the manual disk failling will open. Confirm by typing "Yes".

• If you have a spare disk, leave the box "Copy contents of physical disk before failing" checked.

(The data of the impending disk failure will be copied to the spare disk, to avoid any degradation of a RAID).
 

• If you don’t have a spare disk, uncheck the "Copy contents of physical disk before failing" box.

The disk will have a red cross and will have the status "Failed". The last step is to physically replace the drive.
 

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