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Save a bit of time when using target disk mode System
Yesterday I started up my wife's iBook (G3800/40/512) in FireWire Target Disk Mode, but noted after doing so, that I hadn't first connected it to the eMac (G4700/60/256) I was planning to transfer files from. The iBook display was showing the target mode symbol, so I thought I'd try just connecting the FireWire cable to the eMac. The iBook mounted right away, I copied the files, then unmounted the iBook, which was still showing target mode. I then disconnected the FireWire cable from the eMac and connected the iBook to my iMac (G52Ghz/120/1g) and it mounted just fine there, too, so I transferred a few documents then unmounted it. Of course, I had to do a hard reboot on the iBook to get it out of target mode, but I'd have had to do that anyway.

Apple's documentation on Target Disk Mode states that you should have the cables connected prior to target mode booting, but apparently that's not always the case -- at least not with the Macs I was using. It turned out to be a small time-saver not having to continually reboot the iBook, and I can imagine there are other advantages to doing things this way as well. I'm not sure what the risks are ... but no harm done in my experience.
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Save a bit of time when using target disk mode
Authored by: scatlin on Aug 02, '05 09:56:32AM

I guess I didn't read the documentation on Target Disk Mode. I've always done it this way. However, I did discover over the weekend that you can also pop a disk in the optical drive and it will mount in Target Disk Mode. Now, I wonder if I could burn a CD or DVD in the optical drive in TDM. Hmmm....



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Save a bit of time when using target disk mode
Authored by: wgscott on Aug 02, '05 10:22:54AM

I've always done that your way. Yet another benefit for those who don't read the directions.

It did take me about 2 years to discover that target disk mode existed, however.



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Save a bit of time when using target disk mode
Authored by: jesboat on Aug 02, '05 11:01:45AM

<AOL> Me too! </AOL>

Jesboat

---
With no walls or fences on the 'net, who needs Windows or Gates?



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Save a bit of time when using target disk mode
Authored by: pbonsall on Aug 02, '05 11:33:53AM

Haven't tried burning a disk. Have benefitted from using target disk mode with disks:
I realised my older iBook's optical drive was on the way out when it wouldn't read the latest OSX DVD upgrade disk. I was clutching at straws when I hooked up iBook junior as an external optical drive in target disk mode. It worked!



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Save a bit of time when using target disk mode
Authored by: Spartacus on Aug 02, '05 01:10:01PM

If a CD/DVD shows up in TDM, you should be able to burn discs too. Not all Macs show all of their drives in TDM, though. Some only show the main hard disk (with all partitions). The more recent models (I don't know since when) show the other disks as well as the optical drive.



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Save a bit of time when using target disk mode
Authored by: dirkstoop on Aug 06, '05 07:47:02PM

Does anyone have any documentation on which machines support the sharing of multiple drives over target mode? Couldn't find anything on Apple's support site.

As far as I know this feature was introduced in the first Aluminium PowerBooks, but I'm not sure. Maybe all the folks that work at AASP's or otherwise come in contact with lots of different recent macs should team up and test every possible generation of machines so we'll finally know.. I would be more than willing to put in some effort.



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Save a bit of time when using target disk mode
Authored by: keloide on Aug 02, '05 02:06:20PM

This has always been possible that I know of. I helped prepare almost 3000 eMacs in this way starting with 1 then 2 then 4 then 8 then 16 then by batches of 16. It helped a lot. You can eject and connect another target mode.

You can also use the optical drives in the target unit.

(I know...brag, brag, brag...)

;)



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Save a bit of time when using target disk mode
Authored by: Arno on Aug 02, '05 11:22:36AM

Mmmm, you don't have to do a hard reboot in orrder to restart your iBook, just press the power button for a short time and it will shut down nicely...



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Save a bit of time when using target disk mode
Authored by: qwerty denzel on Aug 03, '05 01:07:05AM

I think Command-Control-Power is restart, or is that counted as a hard reboot?



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Save a bit of time when using target disk mode
Authored by: motarasu on Aug 08, '05 05:59:03PM

On laptops, that's a force restart (same behavior as on the older ADB/beige Macs). Desktops/laptops-with-external-Apple-keyboards have a similar option by doing Ctrl+Cmd+Eject key, though it is a soft restart (have to use the reset button, if available, for a hard restart); other external keyboard options are Ctrl-Opt+Cmd+Eject for a soft shutdown and Opt+Cmd+Eject for sleep.



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Save a bit of time when using target disk mode
Authored by: bomberboy on Aug 03, '05 11:16:55AM

Actually, pressing the power button for 4 seconds is the virtual equivalent of pulling the power cable...

The next time the system starts, fans will come in at full speed and the HD(s) will be fscked = slow boot time.

Not sure if it applies also to Target Mode, but I just had to mention it in case anybody thinks it is safe in normal mode :D



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Save a bit of time when using target disk mode
Authored by: mm2270 on Aug 03, '05 11:43:18AM

This doesn't apply to target disk mode, at least not in all the times I've used it on desktop Macs. In fact, there is no need to hold down the power button for 4 or 5 seconds at all, as you would when doing a hard shut down on a locked up Mac. Just a quick press of the power button of a Mac started up in TDM shuts it down, just as it would for any external FW hard drive. (after you've dismounted itfrom the desktop of the connected Mac of course!)



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Save a bit of time when using target disk mode
Authored by: bomberboy on Aug 03, '05 11:49:07AM

Cool, thanks for the info :)



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Save a bit of time when using target disk mode
Authored by: motarasu on Aug 08, '05 06:01:20PM

Actually, simply pressing the power button will shutdown the machine. You don't need to hold it down.



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Save a bit of time when using target disk mode
Authored by: jiclark on Sep 14, '05 01:46:43PM

From my experience, just yesterday, with the exact set of circumstances as mentioned in the hint, the single press of the power button no longer works if you've left the machine in TDM and moved the FW cable around to use it on another regularly booted machine. You have to press *and hold* the power button to get it to shutdown. I don't think it causes issues though, since nothing on the disk was loaded into RAM; it was really performing exactly like an external FW drive, and you'd never give a second thought to powering down one of those with its switch.

So to clarify: if you use TDM as recommended (hook up FW cable to two machines [one can stay booted], then start up the other machine with T held down), you can indeed shut down the TDM machine by just a single press of the power button if you've ejected it from the other machine's desktop first. But, if you do as described in the this hint (as above, but then disconnect the FW cable and hook it up to a different machine to do more transfers to/from the TDM machine, repeat, etc...) you will have to press and hold the power button for at least 4 seconds to get the TDM machine to shut down when you're done.

Hope that clears this up!



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Save a bit of time when using target disk mode
Authored by: _merlin on Aug 02, '05 09:27:33PM

They probably just recycled the old page for SCSI target disk mode and changed SCSI to FireWire without thinking about what other changes would be appropriate.



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Save a bit of time when using target disk mode
Authored by: kaih on Aug 02, '05 09:42:17PM

FWIW, I'm Apple certified, work for an Apple service centre and all that jazz...
I've always powered machines up, in target disk mode, without having the FireWire cables plugged in, and also used a single machine as a FireWire disk on multiple machines, without power-cycling or rebooting it in between, quite a number of times...
I can't see any reason whatsoever why it would cause damage, and I have never damaged anything doing it this way for years, however I can't guarantee that it will be like this for *you*
I believe that the reason Apple state that the machines have to be connected first is because if there's no monitor on the FireWire Target machine, you can see when to stop holding down the T key by the icon(s) appearing on the host machine...

Cheers,
Kai

---
k:.



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It may also be safer
Authored by: VRic on Aug 03, '05 06:04:23AM
Someone better informed could confirm or correct this: at the time when FireWire networking wasn't built in the OS yet, I recall seing reports of problems when hooking 2 macs via FireWire without target disk mode, which sometimes occurs by mistake when you miss the T key, or release it too soon, or can't help scratching your nose when you shouldn't, etc.

If those are more than rumors, they still stand now because older systems without FireWire networking are everywhere (all OS9 macs without a 3rd party extension and maybe early OSX versions).

So, since FireWire is designed for hot-plug anyway, I always made sure TDM was set before plugging the FW cable, to avoid any electrical or logical problem.

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It may also be safer
Authored by: bdog on Aug 06, '05 12:26:40AM

I'm not completely sure about this, but I don't think plugging two computers via firewire while both are booted on an old OS doesn't hurt anything. I think FireWire was designed to be good like that. HOWEVER, DON'T PLUG IN TWO MACS VIA USB!! It will be bad! And that's why it's hard to find a type a to a USB cable.

I also confirm in whatever order you do this in it won't cause damage. I've done with with ever model of Mac that supports TDM and never had problems.

keloide, you should have used netboot. Would have been much faster.



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Save a bit of time when using target disk mode
Authored by: dirkstoop on Aug 06, '05 07:40:12PM

Another nice way of using target disk mode is by starting up in Open Firmware
(by holding down command+option+o+f during boot) and typing:
target-mode
at the command prompt followed by a return.

This will give you a slightly more verbose version of Target Mode that shows some extra info on connections occuring and the amount of devices being made accesible over the firewire bus on the display of the machine in target mode.



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