OS X diskutil appleRaid Tips and Tricks

By root, 30 April, 2016

Create RAID 1 with missing volume (will destroy the data on the volume):

[osx@mini Volumes]$ diskutil appleRaid create mirror vbox JHFS+ disk2s2
Started RAID operation
Unmounting proposed new member disk2s2
Adding a booter for the RAID partition disk2s2
Creating a RAID set
Bringing the RAID partitions online
Waiting for the new RAID to spin up "2134725A-668E-45C3-BBD6-AAD5FF4D1991"
Initialized /dev/rdisk10 as a 477 GB case-insensitive HFS Plus volume with a 40960k journal
Mounting disk
Finished RAID operation

[osx@mini Volumes]$ diskutil ar list
AppleRAID sets (1 found)
===============================================================================
Name:                 vbox
Unique ID:            2134725A-668E-45C3-BBD6-AAD5FF4D1991
Type:                 Mirror
Status:               Online
Size:                 512.0 GB (511999967232 Bytes)
Rebuild:              manual
Device Node:          disk10
-------------------------------------------------------------------------------
#  DevNode   UUID                                  Status     Size
-------------------------------------------------------------------------------
0  disk2s2   C8F51C23-9D89-4C4D-8F5D-E41A2CAEAEF5  Online     511999967232
===============================================================================

Remove the raid on a volume. This won't destroy the data on the partition, it will simply be converted to normal:

[osx@mini Volumes]$ diskutil ar delete vbox
Started RAID operation on disk10 vbox
Unmounting volume for RAID set 2134725A-668E-45C3-BBD6-AAD5FF4D1991
Destroying the RAID set 2134725A-668E-45C3-BBD6-AAD5FF4D1991
Finished RAID operation on disk10 vbox

How to create (enable) mirror raid (RAID1) on a volume without destroying the data:

[osx@mini Volumes]$ diskutil ar enable mirror /dev/disk2s2
Started RAID operation on disk2s2 vbox
Resizing disk
Unmounting disk
Adding a booter for the disk
Creating a RAID set
Bringing the RAID partition online
Waiting for the new RAID to spin up "B580C0B1-6EEA-4A43-879C-49119544B093"
Finished RAID operation on disk2s2 vbox

[osx@mini Volumes]$ diskutil ar list
AppleRAID sets (1 found)
===============================================================================
Name:                 vbox
Unique ID:            B580C0B1-6EEA-4A43-879C-49119544B093
Type:                 Mirror
Status:               Online
Size:                 512.0 GB (511999967232 Bytes)
Rebuild:              manual
Device Node:          disk10
-------------------------------------------------------------------------------
#  DevNode   UUID                                  Status     Size
-------------------------------------------------------------------------------
0  disk2s2   2F5FD0BB-D9CF-45B6-BEAC-DCAE2287F3F2  Online     511999967232
===============================================================================

How to add new partition to the mirror:

Data will be deleted on the new disk - will be untouched on the existing raid volume. 
[osx@mini scripts]$ diskutil ar add member disk1s2 vbox
Started RAID operation on disk10 vbox
Unmounting disk
Adding a booter for the RAID partition disk1s2
Adding disk1s2 to the RAID Set
Finished RAID operation on disk10 vbox

[osx@mini scripts]$ diskutil ar list
AppleRAID sets (1 found)
===============================================================================
Name:                 vbox
Unique ID:            B580C0B1-6EEA-4A43-879C-49119544B093
Type:                 Mirror
Status:               Degraded
Size:                 512.0 GB (511999967232 Bytes)
Rebuild:              manual
Device Node:          disk10
-------------------------------------------------------------------------------
#  DevNode   UUID                                  Status     Size
-------------------------------------------------------------------------------
0  disk2s2   2F5FD0BB-D9CF-45B6-BEAC-DCAE2287F3F2  Online     511999967232
1  disk1s2   1C29B1E0-C4AE-49E3-826F-624480A3208A  0% (Rebuilding)511999967232
===============================================================================
As you can see above, the rebuilding is started. It will take a wile, depending on your disk speed and partition size. At the end, you should see this: 
[osx@mini sonic]$ diskutil ar list
AppleRAID sets (1 found)
===============================================================================
Name:                 vbox
Unique ID:            B580C0B1-6EEA-4A43-879C-49119544B093
Type:                 Mirror
Status:               Online
Size:                 512.0 GB (511999967232 Bytes)
Rebuild:              manual
Device Node:          disk10
-------------------------------------------------------------------------------
#  DevNode   UUID                                  Status     Size
-------------------------------------------------------------------------------
0  disk2s2   2F5FD0BB-D9CF-45B6-BEAC-DCAE2287F3F2  Online     511999967232
1  disk1s2   1C29B1E0-C4AE-49E3-826F-624480A3208A  Online     511999967232
===============================================================================

How to repair a mirror raid (RAID1):

mini:~ root# diskutil ar list
AppleRAID sets (1 found)
===============================================================================
Name:                 vbox
Unique ID:            B580C0B1-6EEA-4A43-879C-49119544B093
Type:                 Mirror
Status:               Degraded
Size:                 512.0 GB (511999967232 Bytes)
Rebuild:              manual
Device Node:          disk3
-------------------------------------------------------------------------------
#  DevNode   UUID                                  Status     Size
-------------------------------------------------------------------------------
0  disk1s2   2F5FD0BB-D9CF-45B6-BEAC-DCAE2287F3F2  Failed     511999967232
1  disk2s2   1C29B1E0-C4AE-49E3-826F-624480A3208A  Online     511999967232
===============================================================================

mini:~ root# diskutil ar repairMirror vbox 2F5FD0BB-D9CF-45B6-BEAC-DCAE2287F3F2
Started RAID operation on disk3 vbox
Unmounting disk
Adding a booter for the RAID partition disk1s2
Adding disk1s2 to the RAID Set
Finished RAID operation on disk3 vbox

Note: Syncing data between mirror partitions can take a very long time.
Note: The mirror should now be repairing itself.  You can check its status using 'diskutil appleRAID list'.

mini:~ root# diskutil ar list
AppleRAID sets (1 found)
===============================================================================
Name:                 vbox
Unique ID:            B580C0B1-6EEA-4A43-879C-49119544B093
Type:                 Mirror
Status:               Degraded
Size:                 512.0 GB (511999967232 Bytes)
Rebuild:              manual
Device Node:          disk3
-------------------------------------------------------------------------------
#  DevNode   UUID                                  Status     Size
-------------------------------------------------------------------------------
0  disk1s2   A4D2C14C-89C8-4D22-82B2-FEF0F30AECBE  1% (Rebuilding)511999967232
1  disk2s2   1C29B1E0-C4AE-49E3-826F-624480A3208A  Online     511999967232
===============================================================================

How to enable the automatic rebuild on a raid partition:

In the example above, you can see the Rebuild is equal to manual. We want to be automatic. 
mini:~ root# diskutil ar update AutoRebuild 1 vbox
The RAID has been successfully updated

mini:~ root# diskutil ar list
AppleRAID sets (1 found)
===============================================================================
Name:                 vbox
Unique ID:            B580C0B1-6EEA-4A43-879C-49119544B093
Type:                 Mirror
Status:               Online
Size:                 512.0 GB (511999967232 Bytes)
[color=green]Rebuild:              automatic[/color]
Device Node:          disk3
-------------------------------------------------------------------------------
#  DevNode   UUID                                  Status     Size
-------------------------------------------------------------------------------
0  disk1s2   A4D2C14C-89C8-4D22-82B2-FEF0F30AECBE  Online     511999967232
1  disk2s2   1C29B1E0-C4AE-49E3-826F-624480A3208A  Online     511999967232
===============================================================================

How to convert a raid volume into a HFS one (will destroy the data on it):

In the example below, Apple_RAID_Offline is to be destroyed and a new normal HFS+ partition will be created. You want to do this if, for example, you removed a volume from an existing raid set and want to make it normal. It is not an appleRaid trick but will stay here since an Apple Raid volume is involved. 
[osx@mini ~]$ diskutil list disk6
/dev/disk6 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *3.0 TB     disk6
   1:                        EFI EFI                     209.7 MB   disk6s1
   2:                 Apple_RAID                         512.0 GB   disk6s2
   3:                 Apple_Boot Boot OS X               134.2 MB   disk6s3
   4:         Apple_RAID_Offline                         2.5 TB     disk6s4
   5:                 Apple_Boot Boot OS X               134.2 MB   disk6s5
   
[osx@mini ~]$ [color=green]diskutil eraseVolume JHFS+ pool-bkp disk6s4[/color]
Started erase on disk6s4
Unmounting disk
Erasing
Initialized /dev/rdisk6s4 as a 2 TB case-insensitive HFS Plus volume with a 196608k journal
Mounting disk
Finished erase on disk6s4 pool-bkp

[osx@mini ~]$ diskutil list disk6
/dev/disk6 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *3.0 TB     disk6
   1:                        EFI EFI                     209.7 MB   disk6s1
   2:                 Apple_RAID                         512.0 GB   disk6s2
   3:                 Apple_Boot Boot OS X               134.2 MB   disk6s3
   4:                  Apple_HFS pool-bkp                2.5 TB     disk6s4
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