MatthewWhalen wrote:
After upgrading to 10.8.5, my external drives are being put to sleep regardless of the setting in the "Energy Saver" preferences panel.
On its own this isn't so bad, but Time Machine is now failing because of this.
I am experiencing this problem as well. All platter drives (internal and external), that are not the boot drive, are spinning down with the DisplaySleep setting. The drives are ignoring the "put drives to sleep" checkbox being unchecked. They follow the DisplaySleep setting. If DisplaySleep is set to "0", then the drives do not spin down.
I have tried SMC reset, PRAM reset, Safe Boot, a new Admin user account, and none of those procedures result in any change. I have also tried setting DiskSleep to a positive number (with pmset), but it is ignored in favor of the DisplaySleep setting.
My nightly automated backup copies to a drive that is now sleeping when the backup runs. Fortunately, Carbon Copy Cloner seems to have the know-how to wake up the drive, and to wait for the drive to wake up, before running the clone operation. In the logs, I note a 4 second delay from initiation of the job until it actually starts cloning. Prior to 10.8.5, there was no 4 second delay, because the drive was not sleeping. I have booted from the clone, so it is doing a good backup.