Booting from a USB drive

[Timmy]

The FAQ seems to suggest that PPC Macs can't boot from a USB interface, however, I just came across this article:
http://www.macosxhints.com/article.p...61017084322177

Does anyone have any experience with booting from an external USB drive, and if so is it on a PPC or Intel Mac?

[scottb]

Originally Posted by Timmy

The FAQ seems to suggest that PPC Macs can't boot from a USB interface, however, I just came across this article:
http://www.macosxhints.com/article.p...61017084322177

Does anyone have any experience with booting from an external USB drive, and if so is it on a PPC or Intel Mac?

So far, I've not had luck with it.
My drive shows up (SmartDisk FireLite USB2) in the Startup Disk control pane, and I select it, but after a few seconds of what looks like a successful boot, it goes into command-line or single-user mode.

I partitioned as a GUID and cloned the drive using SD!

Have to spend more time on it later, but so far, no luck.

Scott

[dnanian]

You know, PPC Macs can't really boot from USB. Macs with USB*1* ports *might* be able to start up from USB, but very slowly. USB2 Macs that are PPC based can't: I think people are misinterpreting what they're seeing...

[Timmy]

Originally Posted by dnanian

You know, PPC Macs can't really boot from USB. Macs with USB*1* ports *might* be able to start up from USB, but very slowly. USB2 Macs that are PPC based can't: I think people are misinterpreting what they're seeing...

Look at this comment from a user with USB2/PPC hardware:

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
10.4.8

[dnanian]

I know -- I've seen that. It's possible that late-stage Open Firmware changes were made to support that configuration, but I cannot reproduce it on a number of USB2 PPC Powerbooks I have here. And my communications with Apple -- and knowledge base articles at Apple -- indicate that it won't work.

But, even if true in some limited circumstances, USB2 drives are much worse than FireWire drives. They're slower, deal less well with other devices on the bus, don't provide as much current on the port... avoid if possible!

[scottb]

So, how do I make these USB 2 drives boot an Intel Mac?
Haven't had any luck cloning my Mini to a USB 2 drive.

Dave? I know you know

[dnanian]

Just partition them as GUID, back up, and boot from them. No real trick...

[scottb]

Well, that's what I did, and no go.
Not sure why, but it begins the boot process, and then dumps into what looks like single-user mode.

I'll have to do some more research on it.

Scott

[dnanian]

Sounds like some kind of error is likely being displayed... check the system log on the backup after the failure.

[scottb]

For some odd reason, the USB drive had a bunch of "orphaned" files, and once I ran Disk Utility and repaired it, it now works fine.

Odd, but I haven't spent much time at all on this USB boot drive.

Thanks for the help,
Scott

[dnanian]

Peculiar. Glad it worked, though!

[Timmy]

Originally Posted by dnanian

I know -- I've seen that. It's possible that late-stage Open Firmware changes were made to support that configuration, but I cannot reproduce it on a number of USB2 PPC Powerbooks I have here. And my communications with Apple -- and knowledge base articles at Apple -- indicate that it won't work.

Very interesting.

[carabus]

I've been using a bootable FireLite USB drive with my Intel Mac for a couple of months, with no problems at all. I installed OS X to it from the install DVDs, and deleted most unwanted apps and languages to reduce the space used to about 5 gigs.

As a new SD! user, I've been copying users to a sparseimage on this drive - the idea was that any corruption on my Mac would not overwrite the OS on the FireLite. However my 2 gig Parallels Windows XP image on the Mac means that the sparseimage grows by 2 gigs each time I copy it! Hdiutil shrinks it down again, but I think I may repartition the Firelite so that SD! can copy the files directly to the disk, rather than the image.

Roger.

[dnanian]

I can certainly believe that: USB drives should work fine with Intel... But yeah -- if you can, please write directly to the drive. You're always much better off that way.

[Diazruanova]

Hi everybody,

My name is Enrique Diaz (Diazruanova) and I am new to this forum

I would like to say that so far, booting from a USB external disk by creating a SandBox partition, has been a straightforward operation so far!
No problems whatsoever besides a Restart time much longer than that from booting with the original internal drive on my iMac Intel Core 2.
Also i have NOT noticed a perceived delay in opening and working with apps compared to booting with the Mac HD, but I have been working like this just a few hours since the first SandBox restart.

I will post here again if I encounter something odd.