Have you tried restarting in recovery mode and repair disk and disk permissions? Start up and hold Command R until the spinning wheel starts. You can then let go of the keys. Choose Disk Utility from the options screen that is presented in recovery mode. Then repair permissions and then repair disk.
After that restart. Then try starting with a Safe Boot. Maybe that will do he trick. http://support.apple.com/kb/HT4718
Interesting. In helping folks here a couple of them had a problem booting into SM. I took it as a system problem and suggested as Ben, Repair Disk but it did not fix it.
Do you know if this issue is hardware specific and which iMacs, or other models are experiencing the problem because my iMac (3.2GHz Core i3) works as expected in Safe Mode as do many others. Ernest is a 3.4 GHz i7 what are you and do you know if this affects other models?
I do not know if this problem is specific to iMacs and just specific models. I also have an older MacBook Pro and a Macbook as well as another fairly new iMac (2.7 GHz i5) still to be upgraded to Mavericks. I will try to upgrade the laptops this weekend but will wait to upgrade the other iMac until a fix comes from Apple. My affected iMac is a 3.4 GHz Intel Core i7 with a 3 TB Fusion drive and 32 GB of RAM.
Ernest Long wrote:
- It starts with the progress bar on the bottom (at which time I let go of the Shift key),
- The progress bar gets to about 1/3 the distance then disappears,
- The screen goes blank and then my iMac restarts itself and ends up as a normal boot.
Also, iMac sometimes hangs on shutdown and I have to press the power button to turn it off.
Backup your personal files off the machine to a external storage drive (formatted GUID/OS X Extended Journaled in Disk Utility) in addition to any TimeMachine or bootable clone backup (as they might be corrupted as well), unmount/disconnect and then systematically run through these Steps.
In the past if Safe Mode didn't complete it usually meant the drive was corrupted and needed to be erased and everything installed fresh. Perhaps things are different in Mavericks or it's a glitch of some sort.
TimeMachine's data also would be corrupt if it was updated with the glitchy OS X caused possibly by the hard drive, so the entire hard drive would need a 0x-3x seure erase to map off the damaged hard drive sectors and OS X + programs installed from fresh sources and files returned from the storage drive.
Because of the dual flash/hard drive nature of Fusion drives, I'm assumming it can't be securely erased to map off the damaged sectors (just like SSD's can't), thus it would mean the hard drive portion is failing and would have to be replaced. (only Apple can do it now)
I see your issue as a problem on your machine, not yet as a widespread issue with Mavericks itself or else it would have turned up in the testing.
All hard drives have bad sectors, there is a automatical system in place to catch most of them, but there are areas it doesn't work.
Larger drives have more potential of areas failing obviously.
Since the drive can't be completely scrubbed to get rid of them if Apple will not allow it in Disk Utiltiy, it will have to be replaced.
Take your iMac in for service if your Disk Utility has no "secure erase of Free Space" on the boot drive, that would be a clear indication it's not available.
My last resort is to backup to an external drive and erase the boot disk and do a clean install. Not there yet! Machine is still functional, if a bit annoying! I will run some other OEM disk utilities to see if a hardware problem exists. Apple's Disk Utility seems to think that the drive is okay. This iMac is less than a year old.
I disagree with your assesment that any Maverick's problem would turn up in testing. It is impossible to test for all hardware/software configurations. Just look at this software forum and the people that had problems with the Maverick's install (I did not and have post-install problems). I was a software engineer and this is common knowledge. That is why you see a lot of bug fixes released right after new software comes out. Many unique hardware/software configurations out there!
Ernest Long wrote:
My last resort is to backup to an external drive and erase the boot disk and do a clean install.
If you do so, make sure to target the entire disk0 from Internet Recovery with a 3x secure erase if possible.
It will take a long time to complete since you have a large drive, but will ensure all your bad sectors are mapped off.
I will run some other OEM disk utilities to see if a hardware problem exists.
Like I said, run through the Steps, it might be a corrupted NVRAM which is a easy fix and the Steps won't hurt if trying.
Apple's Hardware Test is hold D down on a wired or built in keyboard while booting up until you see something takes a few minutes to load from Apple's servers)
I will run some other OEM disk utilities to see if a hardware problem exists. Apple's Disk Utility seems to think that the drive is okay.
I doubt the other software will assist, then only check the free sectors on MacintoshHD partition, it seems your problem is in the hidden and inaccessible EFI partition. Disk Utility doesn't check for data integrity or for bad sectors.
This iMac is less than a year old.
If hard drives fail, they usually do so within the first year.
Don't even bother, just backup and let Apple replae the hard drive portion of the Fusion drive with a new one under warranty. Make sure to buy AppleCare for two more years of coverage, as since your getting a new drive, it could also fail in the next year.
Since only Apple can replace drives in most Mac's now, your stuck paying their higher prices for repairs when i's usually a easy user level fix in older Mac's.
I disagree with your assesment that any Maverick's problem would turn up in testing. It is impossible to test for all hardware/software configurations.
Apple has volunteers to test new OS X versions on older and varied configurations, I did so at one time.
Also not being able to boot into Safe Mode would for sure be caught at testing, as it's a commonly checked for function.
So that leads more to a hardware/drive corruption issue on your machine rather than a specific Mavericks flaw.
Just look at this software forum and the people that had problems with the Maverick's install (I did not and have post-install problems). I was a software engineer and this is common knowledge. That is why you see a lot of bug fixes released right after new software comes out. Many unique hardware/software configurations out there!
I can understand from your software engineer expereince that you would tend to think that the software is at fault, however as you know software is only as reliable as the structure it's written on.
If your problem was widespread, then yes it might be a fault in the Mavericks code, but it's not and many of the issues on this forum so far are not widespread with many users.
When you've been here for many years, you get to see if patterns develop that might point to a code flaw.
Instead most of the problems with Mavericks so far seem to be individual in nature, which points to a specific problems on each users machine.
I'm willing ot also bet the most issues are with users with hard drives, because bit rot/bad/damaged sectors is a major contribuor o the code becoming corrupted.
We hardly see anyone here with software issues with SSDs.
Apple has not employed significant data integrity checks for hard drives, then users also incur shock damage with portable models.
Take your machine into Apple and let them replace the drive since you will likely be unable to map off the bad sectors yourself using Disk Utiltiy.
If you don't have AppleCare, then purchase it, because if the next drive has bad sector issues and it occurs after the one year warranty has expired, then your looking at out of pocket and only Apple can replace iMac drives now due to proprietary software installed on the drive to work with firmware.
After installing Mavericks on 2 laptops (MacBook and MacBook Pro) and my 21.5" iMac, they can all boot into "Safe" mode. I then installed Mavericks on an external disk on my 27" iMac that is unable to boot into Safe Mode. On the external drive, my iMac will boot into Safe Mode. I suspect that the problem is that my 27" iMac has a Fusion drive and there is some software bug in Mavericks that has a problem booting into Safe Mode when using a Fusioin drive. I will report the problem to Apple and seee what they say.
I've now seen this issue with other Fusion drives. I suspect there may be an incompatibility with Safe Mode in models with Fusion drives.
You can file feedback here. The more who file the more chance it will get fixed.