I would like to create a logical volume group (LVG) with two physical disks.
Issue
The command:
diskutil coreStorage create LVGNAME /dev/disk1 /dev/disk2
returns:
Started CoreStorage operation
Error: -69886: Invalid request
More info
Tested with two USB drives, two SATA disks (one internal, one external FireWire 800).
I can format them with Disk Utility.
I can unmount without a problem.
MacBookPro8,2 with Mac OS X 10.7.4 (same with 10.7.5)
diskutil cs list
No CoreStorage logical volume groups found
With one disk alone I can create a non-composite LVG:
diskutil coreStorage create LVGNAME /dev/disk1
Started CoreStorage operation
Unmounting disk1
Repartitioning disk1
Unmounting disk
Creating the partition map
Rediscovering disk1
Adding disk1s2 to Logical Volume Group
Creating Core Storage Logical Volume Group
Switching disk1s2 to Core Storage
Waiting for Logical Volume Group to appear
Discovered new Logical Volume Group "05F84BFF-DC4D-4DD2-94DB-116FC7F8C804"
Core Storage LVG UUID: 05F84BFF-DC4D-4DD2-94DB-116FC7F8C804
Finished CoreStorage operation
Best Answer
Operating system
Can you reproduce the problem with Mac OS X 10.7.5?
If -69886 arises from a failure to unmount
Expanding upon a hint in an answer to a linked question, try this before the Core Storage operation … for the device that apparently can't be added:
diskutil unmount /dev/disk2s2
– then if the unmount fails, to discover what's open:
sudo lsof /dev/disk2s2
Reference
Currently limited by Apple to Mac OS X 10.7.4: diskutil(8) OS X Manual Page