How to boot from USB 3.0 disk through Thunderbolt dock

[the rock]

Hello,

Hope someone can help with the following problem:

I recently bought the CalDigit Thunderbolt Station that I have hooked up to my mid-2011 iMac 21,5". I have also bought an Icybox external USB 3.0 enclosure with a Samsung SSD 840 drive installed.

My hope/goal was to use the SSD drive as a boot disk for my iMac, using USB 3.0 from the Thunderbolt Station. However, when the USB disk is connected to the Thunderbolt station it is not recognized at boot, and it does not show up in the startup manager. It does mount up normally in Finder as an external USB 3.0 drive. When connected directly to the iMac, using its USB 2.0 ports, it works fine as a startup disk.

Any clues to how to get the drive to work as a status disk using the USB 3.0 interface? Is this related to the firmware of the iMac, or could it be something do do with the external drive and incompatible USB controller?

Any help is greatly appreciated, thanks!

 

[Giuly]

Look like that if you want to boot off of it, you need one of those Seagate Thunderbolt Adapters (and optionally a 2.5" USM enclosure).

 

[HenryAZ]

I asked Caldigit about this (booting from their dock's USB 3.0 ports), prior to release back in September. Their reply at that time:

=========================
Hi Henry,

Unfortunately. you will not be able to boot OS X off of a USB 3.0 drive connected to the Thunderbolt Station.

Best Regards,
Sales Department
CalDigit Inc.
sales@caldigit.com
714-572-6668
=========================

I have also followed the development of the yet-to-be-released Sonnet Thunderbolt dock. Its specs claim OS X booting from the optical drive, from internal SATA, from an eSATA port, and from the Firewire port, but for the USB 3.0 ports, they only say "under test".

I guess there is some limitation in having USB 3.0 connected to the system this way (via Thunderbolt). You can boot from most Thunderbolt connected drives, (not the Promise J4, though).

 

[Fishrrman]

[[ However, when the USB disk is connected to the Thunderbolt station it is not recognized at boot, and it does not show up in the startup manager. It does mount up normally in Finder as an external USB 3.0 drive. When connected directly to the iMac, using its USB 2.0 ports, it works fine as a startup disk.
Any clues to how to get the drive to work as a status disk using the USB 3.0 interface? ]]

The "solution" can be found in your own remarks above.

Connect to an available USB3 port, and boot that way.

Go with "what works" -- don't keep trying to "force a solution" that won't...

 

[Richdmoore]

The OP's computer does not come with any USB 3 ports, only USB 2. (I have the same model iMac.)

I bought the dock as well to add USB 3.0 ports to my 21.5 iMac as well, although not for the purpose of booting. It would be a nice feature to add via a firmware update if it is technically possible (very well might not be.)

The nice thing about the caldiget dock is that it allows another thunderbolt device to chain, so it can still attach an external monitor via hdmi, and then use a chain ending ssd drive if needed for booting. (Even better is a 2 thunderbolt ssd drive to keep the chain going, if they make any.)

 

[the rock]

Thanks for the answers, guys!

I think I'll bite the apple and buy a LaCie 256 gb rugged thunderbolt disk. Just need to be 100% sure that I can boot my iMac off this disk, using the thunderbolt port on the Caldigit dock. Any reasons for why that wont work?

 

[dyn]

It sounds like there are no drivers for the EFI for the USB3. That would explain why I can't enter my Filevault 2 password when I reboot the machine. I thought it might be because I've set a firmware password. Solution is simple: connect the keyboard to one of the usb ports on the machine (it's a MBA 2012; got the dock so I only have to plug in power and TB).