I upgraded to OS X El Capitan a few days ago and was having issues with reboot and shutdown times. It could take up to a minute. So I cloned back OS X Yosemite from a backup and partitioned part of my SSD and installed OS X El Capitan to troubleshoot. Even on the partition OS X El Capitan still shuts down and reboots slowly. When it finally gets to the Apple logo it boots up fast.
Not that big of a deal, just was curious what was going on. OS X Yosemite works fine with no lag in reboot and shutdowns.
I have two boot volumes listed, El Cap that's on a partition, and Yosemite. I select the El Cap partition and it boots fine into El Cap after the restart. and when I'm completely shutdown and boot onto El Cap it boots fine, no lag. Its when I'm booted up into El Cap and do a restart or shutdown. That's where the lag is. I tried Verbose mode and when it started up, it did the white text on the screen then booted normally. I really don't know what I'm looking for here.
Best Answer
Here are few suggestions to troubleshoot the slow reboot issue:
After the system is booted, run:
and check for any errors.
Start up your Mac in safe mode (hold Shift after restart).
/var/log/system.log
file during boot time. Or use the Console.app to check the logs during boot time.kextstat | grep -v com.apple
).launchctl list | grep -v com.apple
).nvram boot-args
).sudo nvram boot-args="-v"
.