10.8.5 puts drives to sleep... forever
Today I updated two systems to 10.8.5: A Mac Pro (Early 2009) and a Mac Mini Server (Late 2012).
Prior to the update I had "Put hard drives to sleep when possible" unchecked in Energy Saver, since I use both systems constantly--and drive sleep just results in lower performance, and more wear-and-tear on the drives.
After 10.8.5, drives will sleep (despite the setting), then never wake up. The drives themselves may spin up, but the OS does not see them. E.g., Finder will give a spinning beach ball when attempting to view the drive, any app with a file open on such a drive will lock up, Terminal will hang on ls of the drive, etc.
This is happening on internal and external drives on both systems.
The only way to get the drives back is to reboot.
Given the severity of this issue, I am restoring my systems from Time Machine backups to OS X 10.8.4.
MAC MINI SERVER (LATE 2012), OS X Mountain Lion (10.8.4)