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In OS X 10.8.2 get "Building boot caches on boot helper partition failed" when changing startup HD.

Since upgrading to Mountain Lion 10.8.2 (problem did not occur in earlier version or Lion) whenever you try and change startup drive or do certain installs get "Building boot caches on boot helper partition failed". This occurs on 3 different partitions on 2 different drives. If boot off 10.7 partition can set any of the 10.8.2 partitions as start up drive no problem and computer boots that partition no problem. Otherwise cannot change start up drive and only way to boot different partion is use the option key at startup.

Mac OS X (10.5.8)

Posted on Oct 18, 2012 10:35 AM

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Oct 18, 2012 10:55 AM in response to Kappy

Guess I should have been more clear - have done all the common things - Disk Utility, Disk Warrior, start in Safe Mode, rebuild/delete caches, and recloned drive and the clone on newly fromated drive behaved the same. The only thing not tried is reformating the working patrtion and reinstalling everything - was hoping to avoid this as since cloning appears to copy the problem would have to at min. do clean install then migrate if not do everything from strach. Once booted everything seems to work fine. Since 10.7 or even 10.6.8 can change startup drive was hoping someone knew of possible Startup Drive prefence panel conflict glitch in 10.8.2. One of the partitions in question is a perfectly clean install - no 3rd party software just updated from 10.8.1 to 10.8.2 and as stated above in 10.8.1 did not have this problem and occurred immedaitely after up grade to 10.8.2.

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Oct 18, 2012 10:40 AM in response to macuserbrla

Open Disk Utility. Select the main disk drive entry (mfgr.'s ID and size.) Click on the Repair Disk button. Do same for each drive.


If this doesn't fix the problem then there is a problem on the hard drive like a corrupted cache file. Start by booting into Safe Mode then restart normally. See if this works.

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Jan 29, 2013 2:14 PM in response to macuserbrla

For what it’s worth, I’ve been having the same problem with 10.8.2, wherein selecting my system drive as the startup disk resulted in the ‘building boot caches failed’ error. After days of research and trial-and-error without success, I was finally able to resolve the problem by booting from a 10.7.5 backup HD, then choosing the 10.8.2 drive as the startup disk. Now when I restart, the MBP boots much more quickly AND the 10.8.2 disk is identified in the Startup Disk preference correctly.


If you don't have a Lion startup HD, perhaps you could try booting from the DVD that came with the computer and using the Startup Disk utility.


MLTH

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Jan 30, 2013 8:36 AM in response to MattLTH

One more thing: After you set the startup disk on a Lion-booted Mac, clearing the PRAM will set this whole problem back in motion. The PRAM reset also resets the startup disk. When you try to choose the 10.8.2 drive, the boot cache error will return, requiring yet another Lion boot to cure the problem.

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Aug 8, 2013 6:13 AM in response to macuserbrla

Okay, so I just ran into a variation of this problem and since this is the top search result I figured I'd add my observations for my particular problem. In my case it turned out that the reason the boot helper partition couldn't be updated was because both the Recovery Partition and my main OS were attempting to update the wrong boot helper partition. In my case this meant that I could only boot my computer in Safe Mode; booting normally would get to just before the login window would appear (or for FileVault users before your desktop appears) at which point it got stuck and wouldn't continue.


For those that don't know, every Mac formatted disk should have a partition scheme that will include an EFI partition, and also a partition called "Boot OS X", however in the case of your main disk the "Recovery HD" partition will fulfill this function instead. You won't normally see these in Disk Utility unless you enable the debug menu (I used Cocktail to do this, but there are Terminal commands available as well) and tell it to display all partitions, or you can use the Terminal command "diskutil list" to view all partitions.


While booted in Safe Mode I noticed the cause of the problem was that I had a mounted Boot OS X volume on my Time Machine drive after trying to set my startup disk. So I unmounted it, and mounted my Recovery HD partition instead. Unfortunately at this point Startup Disk still gave the same complaint by choosing the wrong partition. However, I was then able to use the following command to correct the problem:


sudo bless --folder=/System/Library/CoreServices --file=/System/Library/CoreServices/boot.efi --setBoot


I could then restart normally and login and everything… true luxury living!


Unfortunately for people that need to switch startup disks regularly this probably won't help; I can't for the life of me figure out why Startup Disk is insisting on picking the wrong boot volume. It's a pretty serious bug too as it means that the OS X installer won't work either when running it from the Recovery Partition (I thought I would need to do that to fix my system, should have tried Safe Boot first) since it needs to install something into the boot helper partition.

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Nov 29, 2013 10:42 PM in response to Iain Simms

I installed the OS/X 10.8.5 on my new drive as I would like to have a clean startup disk. My original start up disk is full of stuffs. However, after I restart with my orginal start up disk, I am not able to select the new drive as start up disk again. The error of "Building boot caches on boot helper partition failed" happened whenever I picked the new drive. I tried to reboot on my old drive in Safe mode according to your instruction and entered the sudo bless command line. I restarted my MP and tried to select the new drive as startup, same error occurs. Any idea ?

Thanks.

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Jan 19, 2015 10:01 PM in response to macuserbrla

Okay I may have the same issue. I am trying to set a Lion external USB drive to boot in system preferences. The Lion drive is encrypted. When I plug the usb disk, the OS asks for the password and I enter it in. It shows up as a valid disk for selecting in Disk Start-up but then I get the treaded message. The Macbook air (2011) is booted from an internal partition of Lion (Unencrypted). (The other partition on the Macbook Air is an encrypted Yosemite, which is the default boot drive)


Any thoughts?

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In OS X 10.8.2 get "Building boot caches on boot helper partition failed" when changing startup HD.

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