P2 R4, 3 Drives Raid 5 (3 x 8T (16T Raided)) & 4 Drives (4 x 8T (24T Raided)) - Didn't migrate

  • Last Post 03 February 2021
Rob Badhorn posted this 01 February 2021

HI i recently added a 8T drive to the previous raid5 3 x 8T drive set.  I added 4th drive and migrated but its still showing:

4 Physical Drives: Array0, No. 0-3

1 Disk Array: (0) capacity 32Tm 3.99GB Free Media Patrol Disabled Number of LDs:1

Logical Drive 3 of 4 BLUE (Other one grey) ID:0 Capacity: 24TBm Raid5 Stripe 1M, ReadAhead/WriteBack

WHats the next step?  Am I missing something to Migrate this to a Raid5, 24TB (32TB) singel drive?  

Apple M1 Hardware, 


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Ranjith kumar posted this 02 February 2021

Hi Rob,

Kindly attach the subsystem report at the created web support case id:20210201222150S to assist you on this.

Thank you,


Promise Team

Rob Badhorn posted this 02 February 2021


R P posted this 03 February 2021

Hi Rob,

The migration appears to be successful.

Physical Drives in the Array:  
SeqNo PdId CfgCapacity FreeCapacity OpStatus                                   
0     1    8TB         998.46MB     OK                                         
1     2    8TB         998.46MB     OK                                         
2     3    8TB         998.46MB     OK                                         
3     4    8TB         998.46MB     OK                                         

Logical Drives in the Array: =============================================================================== LdId Alias RAIDLevel Capacity OpStatus =============================================================================== 0 RAID5 24TB OK

The problem is that macOS apparently writes the size of the disk in the disk label.

macOS will allow you to expand a partition (with disk utility) but it will not allow you to expand to larger than what it thinks the disk size is. So while the LUN is now 24TB, macOS still thinks the LUN is 16TB.

This has been an issue that MAC users have been looking for an answer to for a long time.

The only solution is to copy the files off, delete and recreate the LUN from the Pegasus CLI (you need to destroy the disk label), then use disk utiulity to put a new filesystem on the LUN. As an alternative you could also do a quick init to the LUN, that will overwrite the disk label.