PowerVault MD3: Using MDSM to add a disk to a disk group

This tutorial explains how to add one or several disk(s) to the RAID via MDSM software for the PowerVault disk arrays. 

Note: This article is part of the Dell PowerVault knowledge library, available here
Note: Important: The addition of one or several disk(s) in an existing RAID can take a very long time. This is based on the type of RAID and the size of the disks as raid parity needs to be recalculated. A production shutdown is recommended to perform this procedure. It is also highly recommended to do a complete backup of the present data on the array.
 

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Prerequisites:

• MDSM must be installed and the array must be accessible via this software
• The array must be in an optimal state for this procedure
• If you are ;physically adding disks to the storage, add them before below steps.
• Note locations of drives to be added to the disk group

Note: It is not possible to add a different topology disk in an existing RAID. SSDs would not add into a SAS disk group.
 

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Steps:

1. Launch MDSM and select the desired MD3xxx array.
2. Make sure that its state is "Optimal" as seen below.
   
    
3. Double click on the array to access the Array Management Window (AMW).
4. Click on Storage & Copy Services tab.
   1. Note that older firmware versions call the tab Logical.
5. Locate and select the "+" symbol next to Disk Groups.
6. Select the disk group that is being expanded as pictured below.
   
    
7. There are two possibilities to add a disk by using the interface:
   1. Using the File bar
      1. Choose Storage -> Disk Group -> Add Physical Disks (Capacity)...
   2. Using right click
      1. Right click on the Disk Group -> Add Physical Disks (Capacity)...
8. In the following menu, select one or several disk(s) to be added, and then click Add.
   
9. A message will indicate that the procedure can last several hours and then you will have to reconfirm the launch of the operation.
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10. During the expansion, the Summary tab will show "Operations In Progress" clickable link.
11. Clicking on the link will open a dialog box showing estimated time remaining and all steps to that operation.
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12. Once this procedure is finished, go back to the Logical tab to check if the size of your RAID has been extended.