Other threads indicated that the 256 KB block size was the issue, so I tried 128 KB (after wiping the partition tables on the drives using USB to a Linux box), and that worked. So the issue is that "creating a RAID 1 group with 256 KB block size consistent crashes in the RAID module". This is clearly a Lion bug.
I would really prefer a 1 MB block size for a 2 TB drive, to better match the track size.
I can confirm this. Lion 10.7.1 - A RAID 1 mirror across two devices (4GB USB sticks) with a block size of 256k crashes the OS. Lion will continue to crash whenever it tries to mount the RAID volume.
Interestingly, if I create a RAID mirror on a second machine installed with Leopard, same specs, 256k block size etc, and then mount it on Lion I don't see the crash.
A RAID set with a 128k block size does not produce crashes.
It would be good if someone could fix this.
ok i know this issue in max osx 10.7.5 i had it too yesterday with 2x 4TB Harddrive but i do it on an older mac system in my case 10.6.8
but you can do under windows, use this link to re format/initialize a drive as ntfs
hope this helps you
I set up a mirror raid on two external USB drives, and set to 256k under osx 10.7.5 then got the full melt down
and the same every time i tried to reformat the drives.
I did notice a slight moment of time when opening disk utility before the crash!
The following worked for me.
Start the computer, insert just one of the USB or Firewire drives then open disk utility.
Here is the key point as fast as you can select the drive icon as soon as it appears on the left and hit the erase option
don't worry about the type of format select the t hit the erase button as quickly as you can and again as the prompt comes up are you sure you want to erase the disk.
Then repeat again on the second drive and then start the raid set up over again with blocks set at 128k.
Probably advised to unmount all other drives so you do not accidentally format the wrong drive given this is all about haste.
Really hope this helps and think it through as to how it relates to your set up.