Cannot boot from external (or Diskwarrior) on Mac Pro running Snow Leopard

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Cannot boot from external (or Diskwarrior) on Mac Pro running Snow Leopard

Hello,

I have a Mac Pro 2x3 Quad Core running Snow Leopard 10.6.2. I need to restart from an external but it just won't do it. I installed Snow Leopard onto an external drive, selected it as the startup disk and restarted. At best, it gets past the gray apple logo to a blue screen - and then shuts down and starts the restart process again. At worst, it just hangs on a gray screen on restart. I tried this with a couple of different externals with the same result. I also tried holding down option/alt to select the startup disk - but had the same result.

I have the same problem with Diskwarrior 4.2 (and 4.1) - holding 'C' down at restart gets me just beyond the apple logo and then it shuts down and tries to restart again.

If this was just happening with my Mac Pro I'd take it into a Genius Bar and get them to look at it - but EXACTLY the same thing happens with both my Mac Book Pro and my iMac - both running 10.6.1 and 10.6.2 respectively. I have never been able to start any of these machines with any kind of external or boot disk.

Any ideas?

Mac Pro dual 3ghz quad core, Mac OS X (10.6.2)

Posted on Feb 22, 2010 1:40 AM

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Answer 1

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Samsara

Level 4

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Feb 22, 2010 4:28 AM in response to nmbbd

Hi,

How many times have you let it try to restart on it's own? Though it doesn't happen as much anymore, there were a few times I had to let it restart 4 times, possibly 5, to come up. I wouldn't go more than that but ever since I installed SL this has been an occasional issue, especially in the beginning booting back and forth between SL and 10.5.8.

I'm not sure where the problems lies, though I'm inclined to believe if Diskwarrior could get in there it would help. The DW disk you have, it's the one you had to make yourself, right? That's how the update to 4.2 worked. An earlier version than 4.2 can harm the data on the drive you use it on. Only the latest version is Snow ready, something I learned the hard way.

I'm sure you've run Disk Utility on your main drive, not sure if it would be worth it on the other disks, but you might try it on the one you just put a fresh system on.

After that, the only two things that spring to mind are doing a PRAM reset and/or reapplying the Full 10.6.2 Combo Update on your main drive from your desktop. It won't hurt anything, and it may help.
http://www.apple.com/downloads/macosx/apple/macosx_updates/macosxv1062updatecomb o.html

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Answer 2

nmbbd Author

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Feb 22, 2010 4:49 AM in response to Samsara

Hi Samsara,

Thanks for your reply - it's good to know I'm not the only one to have experienced this. I don't think I've let it attempt more than one restart, so I'll give this a try. The clean system was installed onto a freshly formatted external, so I don't know how much good a Disk Utility repair will do, but I'll run it anyway.

The Diskwarrior 4.2 disk was indeed one I made myself using the latest online upgrade - but it still didn't complete a restart. I'll try all you suggest and let you know how I get on.

Many thanks.

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Answer 3

The hatter

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Feb 22, 2010 4:54 AM in response to nmbbd

How did you create the and setup this external? Just straight install and you rebooted and updated it (ASU) and added all the drivers your system needs?

And what are you using? (USB/FW, etc and make of and type of case)

External only worked with Leopard maybe? but never with SL?

You repaired the external with Disk Warrior 4.2 as well?

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Answer 4

Samsara

Level 4

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Feb 22, 2010 4:55 AM in response to nmbbd

Cool, that you haven't let it go for awhile restarting gives me hope, and once you get it to go, it will be easier to start up from the next time.

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Answer 5

Samsara

Level 4

1,321 points

Feb 22, 2010 5:09 AM in response to The hatter

I hope he's busily letting his computer restart while I write.

He's using 4 Firewire drives in the cases he lists in his first post, G-tech and OWC. I'm guessing, because I haven't done it, but it seems he's merely plugging one drive in his rear FW port and plugging in more drives to that. All is fine until he adds a 5th disk. Could it be there is simply not enough power for allowing that?

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Answer 6

The hatter

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Feb 22, 2010 5:23 AM in response to nmbbd

Diskwarrior 4.2 (and 4.1) - holding 'C' down at restart gets me just beyond the apple logo and then it shuts down and tries to restart again.

And why would you boot from CD?

Have you upgraded your system hardware such that the minimum OS is now 10.5.2+ or 10.5.7 or later perhaps?

And yes, I would run Disk Warrior. I would only install OS X if I wanted a small emergency boot volume; or if I had some probllem with my system and wanted to start over or test and see how a clean install went.

Only have one emergency boot drive connected and see what happens.

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Answer 7

nmbbd Author

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Feb 22, 2010 5:30 AM in response to The hatter

The external is a firewire La Cie 'Porsche' drive - it looks like this one: http://www.ipodrock.com/images/LaciePorsche_fw03.jpg. It was formatted using the GUID partition table via Disk Utility (1 partition). I then installed OSX 10.6 from the SL install disk. When the installation completed it prompted a restart which then just hung on a grey screen. When I restarted using the internal and set the external as startup disk, it half-restarted and then shut down etc.

The new Diskwarrior 4.2 disk contains (I believe) OS 10.4 - and this behaved in exactly the same way as the external. I have not repaired the external with Diskwarrior yet - since the boot CD did exactly the same thing I ruled out a problem with the external - but I'll try it anyway.

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Answer 8

Samsara

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Feb 22, 2010 5:37 AM in response to nmbbd

I'm sorry, I'm confusing topics.

Message was edited by: Samsara

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Answer 9

nmbbd Author

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Feb 22, 2010 5:37 AM in response to The hatter

The hatter wrote:
And why would you boot from CD?

And yes, I would run Disk Warrior. I would only install OS X if I wanted a small emergency boot volume; or if I had some probllem with my system and wanted to start over or test and see how a clean install went.

Only have one emergency boot drive connected and see what happens.

My system is 10.6.2.

I'm trying to boot from a CD because I want to run Diskwarrior on the main internal HD... and the one emergency boot drive (the external) isn't starting up properly.

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Answer 10

Samsara

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1,321 points

Feb 22, 2010 5:39 AM in response to Samsara

wrong reply, sorry.

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Answer 11

The hatter

Level 9

60,990 points

Feb 22, 2010 5:43 AM in response to nmbbd

WHAT is the external?

Unless you buy a new CD from Alsoft, it probably can't boot your system.

Use SuperDuper and keep more bootable backups and clones around.

Obviously you don't have "Early 2009 Mac Pro" so forget that we are here.

Are you using the two SATA ports known as ODD (Optical Disk Drive) that are in there? those give you 6 SATA ports, and those are bootable, and can be run out PCI slot adapter.

Snow Leopard doesn't work with some Firewire cases.
Do you still have 10.5 on a backup? or even Tiger? your system came with 10.4.9 if it is dual quad 3GHz 2007.

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Answer 12

nmbbd Author

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Feb 22, 2010 6:07 AM in response to The hatter

The hatter wrote:
WHAT is the external?

Please see post above for description of external drive.

The hatter wrote:
Unless you buy a new CD from Alsoft, it probably can't boot your system.

OK - that's no good then.

The hatter wrote:
Use SuperDuper and keep more bootable backups and clones around.

OK - I hadn't heard of that before - I'll take a look, thanks.

The hatter wrote:
Obviously you don't have "Early 2009 Mac Pro" so forget that we are here.

Sorry.

The hatter wrote:
Are you using the two SATA ports known as ODD (Optical Disk Drive) that are in there? those give you 6 SATA ports, and those are bootable, and can be run out PCI slot adapter.

No - I've just been trying the Firewire so far.

The hatter wrote:
Do you still have 10.5 on a backup? or even Tiger? your system came with 10.4.9 if it is dual quad 3GHz 2007.

I'll try installing an older system onto the external and try that as you suggest. Thanks for your comments.

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Answer 13

nmbbd Author

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Feb 23, 2010 2:21 AM in response to nmbbd

OK - success on all machines. I installed 10.5.2 onto a La Cie Porsche USB external, GUID partitioned, and this successfully booted up my Mac Pro, iMac and Mac Book Pro, all running 10.6.2.

I ran Diskwarrior 4.2 on all three without a hitch. Thanks for your help and advice.

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