Yup, I just booted up from an Iomega 250 GIG external drive which can be connected with either FireWire or USB 2. It's currently connected with USB 2 because I've had trouble using it with FireWire. It was slow starting up but worked just fine.

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For the cloning of the startup disk installed system to an external USB2 disk, I find "Carbon Copy Cloner" easier (..& free) alternative to the mentioned SuperDuper. That is because Carbon Copy Cloner (CCC) lets the user copy JUST the necessary files without the whole HardDisk (maybe I'm wrong, but didn't find such option in SuperDuper).

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It's slow, but it works.

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I did this in late July, so it is not a 10.4.8 feature. It has been around for at least that long.

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This didn't work for me. I have an iMac G5 1.8ghz running 10.4.8 and an Iomega 250GM USB drive.
I tried it with bluetooth keyboard and usb keyboard. Both let me hold option to get boot menu, but all I see is my internal drive and I don't even seem able to select that. I see a reload icon and a right arrow icon and the drive in the middle, but the arrow keys don't do anything..

Is there something that needs to be done to set the external drive as bootable to be recognized on this menu?

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Use the appropriate tool to copy the System files to the external drive and use the mouse to select it in the menu that appears when you hold down the OPTION key during boot? =)

---
:: Jedi Knight ::
-- Mac Rules! --

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Sometimes if volumes don't appear in Startup Manager (what you get when you hold down the Option key at startup), you need to reset the Mac's PRAM, NVRAM, and Open Firmware. Shut down the Mac, then power it up, and before the screen lights up, quickly hold down the Command, Option, P, and R keys, until the Mac has chimed twice more after the powerup chime. Then, before the screen lights up, hold down Command-Option-O-F until the Open Firmware screen appears. Then enter these lines, pressing Return after each one:

reset-nvram
set-defaults
reset-all

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Could this be used to boot from a Flash Drive? Thinking of adding a couple of gig to my Mac mini webserver in order to "save" the hard drive.

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One problem with booting OS X from a flash drive, is all the write operations that take place on the boot volume while OS X is running (including virtual memory swapfiles) might eventually cause the memory locations on the flash drive to reach their maximum rated number of write operations after a shorter time than a hard drive's disk sectors.

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But in specific, late answer to the question, yes, most flash drives (bootable ones--some early ones aren't bootable, and some early (and maybe some later?) USB drives aren't bootable) will boot OS 10.4.3 and later, from USB (1.1 and 2.0), on most Macs, starting with the slot-loading iMacs, the AGP/Sawtooth G4, and the Powerbook G3 Firewire. Some late-model Powerbook G4s don't seem to be able to boot from USB, but I haven't tested that much, to see if something else was going on that might be resolvable.

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Why wouldn't this work on an intel mac?

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The boot meny appears when you hold down the OPTION key after starting your Mac?

Do you have a GUID partitioned drive with the system files?

If the answers to the above questions are both yes, I think so...

---
:: Jedi Knight ::
-- Mac Rules! --

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Booting from a USB 2.0 drive has always been possible on Intel Macs.

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Starting with the release of the AGP G4 towers, Macs gained the ability to boot from USB-connected media in general. For some reason, historically, Mac OS X specifically wasn't able to boot from a USB-connected device on a PPC Mac. When the x86 Macs were released they could boot OS X from USB media, but PPC machines still couldn't. So this ability to do so now is new and perhaps not as simple as "now it works." It may not be supported and may instead just be a coincidence of installation that a handful of people have run across.

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It was a feature added to OS 10.4.3 and later.

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This is weird, because I was recently trying to do exactly this, to implement another tip here regarding making a single drive that could boot both Intel and PPC Macs. When it came time to install Tiger on the PPC partition, it woudn't let me, stating something like "can't install on this drive because this computer cannot be started up using this drive". I did some searching, and seemed to find near universal consensus that PPC Macs couldn't boot from USB (2 or otherwise).

So what gives here?

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My co-worker and I did this a few years back with a G3 iBook, 32MB flash stick (I don't call them drives, they aren't drives!) and a very stripped down install of OS 9. It booted very slowly, but worked.

For those of you who have trouble; Is your system blessed on the external drive?

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(I don't call them drives, they aren't drives!) Sure they are. They just aren't disk drives.

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Here is the difference; A disk requires a drive to operate, and that is two devices. Solid state memory is just one device (the storage medium is the read/write controller as well). If you read the below definition, it implies that there are TWO devices.
A device that reads data from and often writes data onto a storage medium, such as a floppy disk.

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This has been possible for quite some time, at least since 10.3. If I'm not mistaken, this is how they do software restores at Apple retail stores, though I'll bet they use firewire whenever possible.

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So if im understanding this correctly, i can backup to my usb external drive thats formatted as HFS+ with a GUID partition table, and be able to boot my Intel MacBook Pro off of it???

Thanks,
Nate

PS (I have the enclosure, but my backup drive is dead, so im trying to figure out whether i should just get a firewire or 3x interface external drive instead.)

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It's a distinction that has no real meaning. A flash drive is conceptually two devices. It's the storage media and the logic and electronics that know how to invoke a state change to store and retrieve data thereon. Just because they happen to be in the same package doesn't really invalidate it. A hard (nee fixed) disk drive is only a single device as well.

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I found the following interesting anomaly when attempting to boot from my USB 2.0 Western Digital "My Book" drive. First I tried to make a clone of my Mac's drive using RsyncX. While it appears that the synchronization process was successful, I found I was not able to boot from the remote drive as I expected (it's well known that booting from an external USB drive isn't supported on Macs). I then tried, as the comment suggested, making my backup clone with SuperDuper!. Somehow, my Mac was actually able to boot off the USB 2.0 drive using the backup clone made by SuperDuper!.

I don't know exactly what SuperDuper! does outside of simply copying files so I can't speculate on why this program allowed my Mac to boot off a USB 2.0 drive. I'll provide my system information in case it helps someone figure out why this worked.

Powerbook G4 12"
PowerPC 1.33 GHz

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I'm also running 10.4.8

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Hmm, same machine here, well, almost: 12" Powerbook, 1.5 GHz, 1.25 GB RAM, 160 GB HDD, running 10.4.10. Made a clone with SuperDuper 2.1.4 to an 2.5" HDD in an external USB housing, took about 90 minutes, as fast (or slow) as Carbon Copy Cloner or Disk Utility restore. Looked good, almost everything got across oK (except, thankfully, for the virtual memory partitions;-), but no-go. Not with option at startup, nor selectable in the Startup Disk Panel. I did the backup with the formatting option and the permissions repair enabled, but that shouldn't do any damage. So, what am I missing here?

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Some late-model Powerbook G4s don't seem to be able to boot from USB. Though other factors might be at play: this user's USB drive might not be one that supports booting; he may not have reset PRAM, NVRAM, etc.

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Not so easy as it makes it sound.
especially for someone in my position, whose internal hard drive is more than twice the size of their external. for me, i have 350gigs worth on my internal drive, but my external is only 150gigs.
So I created my own custom copy script in superduper, to exclude my the folders that contain large amounts of data i don't need backed up.
This cut down the size to something that fits. all of the ignored folders are in my home folder, so i don't think it should inhibit the system from booting. Superduper says it did it all, but alas, i cannot get it to appear in startup disk panel, or by holding option at startup, or even with the older Open Firmware bit.
I have a G5 quad powermac, 10.4.8. WHAT AM I MISSING!!

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i have a powerbook G4 1.5Ghz with 10.4.8. I used SuperDuper today to copy my computer hard drive to a Western Digital My Book USB2 drive. SuperDuper said at the end of the process that the drive was made bootable, but the SuperDuper website is clear that this should not work on a USB drive. After the copy was made, i noticed that the number of files copied was a little less than the total number of files, whatever that means. I checked in StartUp Disk/System Preferences and the USB2 drive partition with the system did not show up as a choice of start up drives. Only the computer hard drive showed up with the system. After I read this hint, i tried holding down the Option key and restarting but it didn't bring up the external disk partition--the only choice that came up was the computer hard drive system folder. I tried it twice. I may be doing something incorrectly.



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Never worked on my Pmacs dual G5 2,0 and 1,8.
Neither on my Pbook 1.7

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Actually I am loading my iBook 500 g3 with tiger from a USB 1.1 as I type this. I tried a lot of goofing around but working with an old USB external DVD is working fine. I replaced the iBook hard drive and didn't have a CD version of Tiger. The external drive is an old USB klunker. I did find that the DVD drive you use makes a great difference. It seems half the DVD rom (IDE) drives out there do NOT provide the boot code the MAC wants to see. I have three drives that would not boot my iBook. The one I am using now is a Samsung (ugg) DVD/CDRW from Micro-XXXX. (The $29 variety) Boot with the option key, Bios shows both the internal and external DVD and has allowed a flawless (pretty slow) installation.

---
Michael

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I am trying to boot OSX from a USB flash drive. I am using an imac. I need to wipe the drives on several Macs the school district is getting rid of and some of the CD roms don't work. I copied the OSX disc to my drive and tried to boot from the flash, but it doesnt see it. It only gives me the arrows and sees no drive. Any ideas? I'm not sure how SuperDuper would work in this instance.

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Hi all !

Here is my "success" story...

I had a PB G4 with a dead internal hd, and I have bought an external usb 2.0 drive. I was told by apple tech support, that booting off the external drive is impossible on g4 computers.

Then, I have stumbled upon this site, and with SuperDuper, I have made a complete backup of the neighbour's mac mini. I borrowed the mini, did the backup, and in SuperDuper, all of the booting related options were greyed out.

I have tried booting the mini from the external drive, and it did not work.
Even if i held down the option key, the drive did not show up in the bios.
I wasn't able to select it as a startup disk, either.

Then, I was curious, how would my PB react to this new situation with a -supposedly- bootable version of 10.4 on the usb drive.

And, tadaa, as I went into the bios, the drive showed up !

I was able to boot the system, and I can use it now, it's not really slow at all for general usage. Only the booting is slightly longer than usual.

I didn't really notice anything bad, all the new hardware parts, airport, etc were detected instantly.

It is working fine, however, there are strange things.

Sometimes, the drive doesn't appear in the bios, but boots.

Sorry for the long post, and the bad english.


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Best I can tell, from my experience and that of people posting above:

• USB 1.1 and 2.0 ports/drives have always booted OS 9, on any Mac that can boot into OS 9.

• Macs up through the Powerbook G4 1.33 GHz, and at least some desktops of the same vintage, and maybe a few other pre-Intel PPC Macs (not sure why not all the pre-Intel PPC Macs), will boot from USB 1.1 and 2.0 ports/drives into OS 10.4.x (at least 10.4.6 and above--I didn't try earlier versions)--NOT OS 10.3.9 or earlier. Older Macs may need their firmware updated to the last version available for that Mac model, and not all USB drives might boot. Some USB drives will appear in Startup Manager (what you get when you hold down the Option key at startup), and others won't; when they don't, reset the Mac's PRAM, NVRAM, and Open Firmware (see my steps above), and that may allow some of them to appear in Startup Manager.

I found out that 10.4.x will boot from USB today, by surprise, when I had a USB drive in a 3.5" MacAlly drive enclosure, connected to an iMac G3 slot-loading, 350 MHz, since this model doesn't have Firewire ports, whose internal drive didn't yet have an OS on it; I had booted the Mac from an OS 9.1 CD to set its clock, then I restarted the Mac, and ejected the CD, and to my surprise, the Mac then saw my USB drive's OS 10.4.8 volume, and booted from it. It was slow, but not impossibly slow. It also appeared in this Mac's Startup Manager, and I could select it in the OS 10.4.8 Startup Disk prefpane. However, as I expected, I couldn't select the drive's OS 10.3.9 volume in Startup Disk--I just got a system beep when I clicked the Restart button--and when I selected the OS 10.3.9 volume in Startup Manager, it started to boot, showing the Apple logo on a white background, and the spinning activity indicator, but after about a minute, the Apple changed to a slashed circle.

I do remember reading that Apple never said it wasn't possible to boot OS X from USB ports--they said it was a decision they made to prevent it, because OS X booted and ran so slowly from USB. Some people have said it's a limitation of the firmware, or Open Firmware, but that doesn't appear to be the case, unless it's a few Mac models just prior to the Intel-based Macs that can't boot 10.4.x from USB, as illustrated by some user examples above, unless there was some other issue preventing them.

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A late clarification to my post above: I later found that OS 10.4.3 is the minimum OS X version for USB booting.

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Hi Mike,
Thanks for the hint. I have two problems which I need your help on. I'm 3 days old using Mac. I have an iBook G3 600Mhz/384MB dual USB running on OSX 10.1.5. I'm looking into upgrading to Tiger or Panther as 10.1.5 is very annoying (as you know, I'm sure). How do you managed to install Tiger without the CD? Did you copied from your old hard drive? or you ripped the image off a CD?
Another problem is the USB drive, it doesn't seem to detect anything I put into it. I have a USB external hard disk, a Sandisk Ultra II USB plus SD card and Belkin 54G wireless dongle. When I plugged in the external drive or the SD card via USB, I get an error saying something like "there are no readable volumes" and prompted me to repair or initialize it. but when I did, nothing happens.

What should I do? Please help as I can't afford to buy another Windblows laptop.
Many thanks in advance!!!

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Your post worked GREAT, but I have a few things to add...

-- To upgrade OSX 10.4 on a iBook G4 and PowerMac G4 (both running Tiger) to Leopard 10.5 with only a DMG and USB drive --

- Download/Install: Carbon Copy Cloner at [link:]http://www.bombich.com/software/ccc.html[link:]

- Copy the DMG to the laptop

- Connect a USB drive WITH external power source to the laptop

- Using Disk Utility: Erase the drive

- Open "Carbon Copy Cloner" and select the DMG of the install disk

- Select "Use block-level copy" "Erase drive"

- Click "Clone"

Once the clone is complete, reboot the Mac and perform the open-firmware changes mentioned in this post. You should then be able to install from the external USB drive like it was the actual DVD.

**NOTE** I do NOT endorse stealing software. I obtained my DMG from our Apple Enterprise License at work and downloaded it directly from them.

Once you see your new OS you will need to reset your firmware so it doesn't try and boot from the USB drive anymore.

- Reboot the computer and press:
Command-Option-P-R
This resets the firmware to the factory settings.

Keep holding this until you hear three "Bongs". Once you release, the Mac should boot normally into your new OS!

ENJOY!!



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I forgot to add that you want to clone to the USB drive (if this wasn't understood)

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I have succesfully booted a Leopard install using a USB2 drive on my powerbook g4, and it was running at USB2 speeds (averagnig about 6mb/s when using SuperDuper to backup from an external booted upon USB2 drive to an internal drive)!

So if you have Leopard, you can boot off of USB2. About time I'd say.

Screenshots and more information here: link
PS: SuperDuper Leopard backups are not yet bootable (as of 2.1.4), but I used disk utility and it worked fine.


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I have a PowerBook G4 1.6 w/ 15" screen running OSX 10.4.11, and was in the process of switching HD from 80GB to 250GB. Never enough disk space. None-the-less I came accross this thread and it was a life saver. First of all, I finally got a clear indication that holding down the Option key was all I needed to do to select my boot drive on powerup. Even better, I was able to easily move from my old internal to the new internal by using SuperDuper ([link:] www.shirt-pocket.com/SuperDuper/SuperDuperDescription.html). Wow it WORKED! I was able to test the new drive before even cracking the case. So after I finished the drive replacement I purchased a registered copy, its that good. thanks to everyone.

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There are several posts in this thread that refer to "copying" an installation to another disk, in order to boot from it. You should know that OS X DOES NOT SUPPORT a simple copy of a System installation to another drive. It will not boot. The only way to do it is with a program that knows how to make a copy "bootable". I believe that the only utilities that make it possible are SuperDuper, CarbonCopyCloner and Apple's own Disk Utility.

So unless you're using one of those utilities to clone your working OS X installation to another drive, it's virtually certain that you'll fail. Also, from reading this and another hint on the topic, it sounds like there are two other things that might make some difference:

1) When formatting the drive you want to clone TO, don't check the box labeled "Install OS 9 drivers", and...
2) Make sure you're cloning an installation that is specifically 10.4.6 or newer (and by extension, you might want to make sure the system that you're booted from to do the clone, meets that requirement as well?)

Good luck, and post back when you discover tips or tricks that seem to work for you!

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Even though I highly recommend both SuperDuper and CarbonCopyCloner (and in fact use SD to make bootable external backup drives for client's machines all the time) I thought it prudent to point out that you really shouldn't use either to clone a hard drive from an old machine to use in a new machine if the new machine is not of the same processor family as the old one!

In other words, it can be dangerous to think that an installation created for a PPC machine will work fine in an Intel one. Best to do a clean install, then copy your data over manually.

Hope that makes sense!

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Okay, I kinda get how to do it. But if someone out there can give me the answer to these very basic questions I think I may have found success...

1. Does this work for Imac G3 600mhz?
2. I haven't used it yet but I got a 250gb Western Digital USB external drive, will it be compatible?

I'm sure I'll have a ton of questions after these two are answered.
Thanks

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