LSI MegaRAID: How to convert between Dedicated Hot Space (DHS) to Global Hot Spare (GHS)?

Question

To see your drives, use storcli /c0 show all or storcli /c0/eXXX/sALL show (replace XXX with the enclosure ID or EID). In my case, the output looks like this:

Drive Information :
=================

--------------------------------------------------------------------------------
EID:Slt DID State DG     Size Intf Med SED PI SeSz Model                Sp Type 
--------------------------------------------------------------------------------
252:0    10 Onln   0 2.728 TB SATA HDD N   N  512B WDC WD30EFRX-68AX9N0 U  -    
252:1     9 Onln   0 2.728 TB SATA HDD N   N  512B WDC WD30EFRX-68AX9N0 U  -    
252:2    11 Onln   0 2.728 TB SATA HDD N   N  512B WDC WD30EFRX-68EUZN0 U  -    
252:3     8 Onln   0 2.728 TB SATA HDD N   N  512B WDC WD30EFRX-68EUZN0 U  -    
252:4    12 Onln   - 2.728 TB SATA HDD N   N  512B WDC WD30EFRX-68EUZN0 U  -    
252:6    14 GHS    - 2.728 TB SATA HDD N   N  512B WDC WD30EFRX-68EUZN0 U  -    
252:7    13 GHS    - 2.728 TB SATA HDD N   N  512B WDC WD30EFRX-68EUZN0 U  -    
--------------------------------------------------------------------------------

How do I convert GHS to DHS or the other way around?

Solution

storcli won't let you change the state of the disk as long as it is "allocated" as hot spare. To deallocate the drive, you need to "delete" it:

storcli /c0/e252/s7 delete hotsparedrive

This will make the disk 13 (in Slot 7) attached to enclosure 252 connected to controller 0 available:

EID:Slt DID State DG     Size Intf Med SED PI SeSz Model                Sp Type 
--------------------------------------------------------------------------------
252:7    13 UGood  - 2.728 TB SATA HDD N   N  512B WDC WD30EFRX-68EUZN0 U  -    

The state is now "UGood". That means you can add the disk to an existing array or convert it to a dedicated/global hot spare.

To make it a global hot spare, just add it without any extra options:

storcli /c0/e252/s7 add hotsparedrive

To dedicate it to a drive group, also specify the drive groups:

storcli /c0/e252/s7 add hotsparedrive dgs=0,1

This command would assign the disk as hot spare to the disk groups 0 and 1.

To extend an existing RAID 5 array, use this command:

storcli /c0/v0 start migrate type=raid5 option=add drives=252:7

/v0 is the volume to which to add the disk. drives gives the list of disks to add. The list is comma separated and each item is EID:Slt (enclosure ID and slot), i.e. the value in the first column.