Cannot Do A Safe Boot In Mavericks

Question

Everytime I try to boot my iMac into Safe Boot mode after installing Mavericks, this is what happens:
- 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.
I have tried with and without any external peripherals connected.
Also, iMac sometimes hangs on shutdown and I have to press the power button to turn it off.
Anyone else experiencing similar problems? Any suggestions? Thanks in advance!

Answer 1

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.
Good Luck