03 February 2021
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.