Yosemite: boot hangs at 50% percent

Worked for me ! Though I didn't bother with the safe boot mode but went straight to normal. Many thx

Hi,

I have got the same problem. Could you elaborate more about what you did?

I mean , if the system is stuck you cannot reset NVRAM..

SO did you do a NVRM reset before the update? Or did you do it after a reboot?

And now, does your imac still show a progress bar during boottime?

I just rebooted the imac, it works fine, but I still got a progress bar under the apple logo and boot takes 3 minutes…..

Thanks for your help!

Leen

When the system is "stuck" hold the power button down until it shutdown and then reboot resetting NVRAM (never did this before installing Yosemite). From what I read on here its normal now in Yosemite for the progress bar to show during boot sequence.

I still have problems when I leave the iMac for a period of time even though I have the "Never Sleep" option set. The machine just hangs so I have to reboot. It always takes a minimum of 2 reboot attempts to get going. Generally if it hasn't gotten to the login screen within 75 secs it means it neve will so I just reboot again until it does

Also on more than 2 occasions while working the iMac has just hung. In the process of trying to work out why: I have removed all startup programs and uninstalled a few add ons that appeared at the bottom of system preferences like OSXFuse. I was also using Chrome when it went both times so just in case am now using Safari exclusively

I tried our advice. No change. Te system reboots, but the progress bar takes something like 55 seconds after the chime to fill before the login appears. I Can live with that, but is it normal?

Boot into the Recovery volume (boot with the Command + R keys held down), select Disk Utility and repair both the disk permissions and disk. Reboot normally and see if there's any improvement.

If not I'd reboot into the Recovery volume and reinstall the system.

TThat was exactly my first issue too. I solved it by pressing the power button twice to reboot it. As simple as that.

anyhow, iT boots. I Will wait for THE next fix level. Should come soon :-)

I've had the same problem. I thought it was a lot of things, actually: FileVault, Screen Saver, Login Keychain, etc. Looking at the TRIM settings and such with my SSD was a non-issue as the TRIM support was disabled on my drive with 10.10. I've been trying lots of different settings on the Mac to see if there was one which would make it stop misbehaving as Mavericks worked wonderfully.

While pondering this, the errors, hangs, and whatnot do look suspiciously like a drive issue and I thought the problem might be HDD hibernation since the manifestations seem consistent with a drive on the way out. I turned this off and have been running pretty smoothly.

Under Preferences -> Energy Saver, uncheck "put hard disks to sleep when possible."

I wonder if this will work for more people than I.

FWIW, I have an early 2011 MBP (MacBookPro8,1)

it looked promising, i had also hibernation on, boot the initial boot still failed at 50% after turning it off.

But again, I rebooted the system by using the power off/on with no special keys and it is running.

the only thing that still puzzles me is the progress bar that appears during initial boot and is there for about 50 seconds.

but everything works fine.

Any success here? I have a bunch of macs at our business that are doing this. I can reboot to safe mode and get them to come up - but that's kind of a band-aid.

Have you tried reinstalling the system from the Recovery volume and then repairing disk permissions?

had the same issue. here is what worked perfectly

1. Reset the SMC -

2. Reset PRAM

MacBook Air SMC and PRAM reset

took 30 secs and rebooted and VIOLA, instant fix.

I had FileVault turned ON in Mavericks before the upgrade install and didn't need to do anything with that. FileVault works fine.

Check out the ~11th reply in this discussion. It seems to be related Active Directory.

By the way, for all the comments above about safe boot... That isn't needed (red herring)... Just reset the PRAM and boot with the network unplugged, with wireless turned off. See the discussion I linked at the beginning of my reply.

I hope that helps.

I also noticed that turning off my bluetooth cleaned the boot process and time up dramatically. i saw in other post that users were having issues with bluetooth. I rarely use bluetooth and once i turned it off, things seems to work much smoother. Not sure why but whatever. C'mon Apple, time to step up the pre-release engineering/troubleshooting efforts.