In target disk mode, how long does it take for a mid-2011 iMac hard drive with 250 GB of data to show up on a mid-2017 iMac using a USB-A to USB-C cable?

Question

In target disk mode, how long does it take for a mid-2011 iMac hard drive with 250 GB of data to show up on a mid-2017 iMac using a USB-A to USB-C cable?

I want to manually transfer files from my mid-2011 iMac to my new mid-2017 iMac.

Starting up my mid-2011 iMac using target disk mode, how long does it take for the mid-2011 iMac hard drive with 250 GB of data to show up on my new mid-2017 iMac desktop using a USB-A port from the mid-2011 to the mid-2017 iMac USB-C port?

I've been waiting for 20 minutes now watching the thunderbolt and USD white icons move around my 2011 iMac screen with gray background.

Thanks much.

iMac, macOS High Sierra (10.13.2), mid-2017 iMac, 27-inch

Posted on Dec 16, 2017 1:22 PM

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Answer 1

SeaPapp

Level 7

26,486 points

Dec 17, 2017 6:14 AM in response to Sherewshevsky

I'm answering because no one else has. I don't have a thunderbolt or usb-c Mac but I think you need to be using a Thunderbolt 3 to Thunderbolt 2 adapter and connecting to the 2011 iMac through it's TB port. Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter - Apple

I've only ever used Firewire Target Disk Mode but it has connected quickly just as any other external drive.

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Answer 2

SeaPapp

Level 7

26,486 points

Dec 17, 2017 9:14 AM in response to Sherewshevsky

Like I said I've only used firewire target disk mode so I don,t know about using usb. I don't know that a 2011 iMac supports TDM over usb. The way I read it TDM over usb is supported on the Macbook because it doesn't have firewire or thunderbolt. The target disk should mount almost immediately.

Check to make sure the cable is plugged in securely at both ends and you’re following the steps exactly Use target disk mode to share files between two Mac computers - Apple Support

Check to make sure that you're using a known good cable also.

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Answer 3

SeaPapp

Level 7

26,486 points

Dec 17, 2017 5:21 PM in response to Sherewshevsky

I mean, as babowa just pointed out, that I don't believe you can use Target Disk Mode with USB on a 2011 iMac. You need to do it over Thunderbolt. If you don't want to spring for the proper cables and adapter consider transferring the files using Air Drop Use AirDrop to send content from your Mac - Apple Support

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Answer 4

SeaPapp

Level 7

26,486 points

Dec 21, 2017 3:10 PM in response to Sherewshevsky

I've run out of ideas. Try resetting the SMC on both computers How to reset the System Management Controller (SMC) on your Mac - Apple Support

If you can't get it working with TDM why not use Air Drop to transfer the files?

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Answer 5

Dec 17, 2017 8:24 AM in response to SeaPapp

Thank you, Mike. If I use the Thunderbolt method, I'd need to buy the T3 to T2 adapter PLUS another cable with T2 on both ends, right?

But I don't see why a USB cable (USB-A from the 2011 iMac to USB-C from the 2017 iMac)I'm using now doesn't work for me. After all, both computers have USB ports just that the 2017 port can handle a faster transfer of data.

And then there's this:https://techinternets.com/copy_calc

Thank you.

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Answer 6

Dec 17, 2017 4:45 PM in response to SeaPapp

Thanks again, Mike.

I'm using a Belkin cable and it's securely connected to both computers. I don't know what you mean by "TDM over USB." The 2011 iMac has USB 2 ports and Thunderbolt 1 ports.

Does USB 2.0 support disk target mode?

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Answer 7

Dec 21, 2017 2:43 PM in response to SeaPapp

I bought a Thunderbolt 3 > thunderbolt 2 adapter and a thunderbolt cable, hooked it up between my mid-2017 and ned-2011 iMac. Then started up the mid-2011 iMac in target disk mode. Same problem as above when I used the USB cables. The icon of the 2011 HD does not pop up on the desktop of the 2017 iMac, and I see floating thunderbolt and firewire icons on the 2011 iMac screen! I'm not using firewire cable, as I mention.

Please help.

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Answer 8

Drew Reece

Level 6

10,660 points

Dec 21, 2017 3:26 PM in response to SeaPapp

Mike Sombrio wrote:

I've run out of ideas.

I'd try running the 2017 iMac in target disk mode to see if that appears on the 2011 iMac. Thunderbolt cables & adapters can be odd at times, especially when used with older hardware.

Another option is to use File sharing over an ethernet cable. Ask if you need help to set that up.

If you are migrating a user or the entire OS you can use an ethernet cable & Migration Assistant to move the data. Just run Migration Assistant on both Macs & follow the prompts with the ethernet connection between both Macs (no router required).

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