Scheduled Shutdown and External Hard Drives

1. Nick Naym - 4 October 2008

   I have my iMac scheduled (via Energy Saver prefs) to shut down at 3 AM and start up at 8 AM. I'm not sure if I should adhere to such a routine, or simply leave the machine running 24 X 7 (both alternatives have their vocal supporters, and I'd welcome your opinions. :) ).

   I also have Time Machine backing up to an external drive, and will be running SuperDuper! to a second, daisy-chained external.

   Prior to getting this machine, I'd only connect an external drive when I wanted to perform a manual backup; I'd then dismount it and turn it off, _especially_ prior to shutting down the computer to which it was connected. As I understood it, that was the recommended way of connecting/disconnecting an external drive.

   But now that the externals are always connected and "on" to enable automatic backups, I'm unsure what happens when the Energy Saver schedule kicks in to shut down the iMac: Does it shut down the system "gracefully," by first dismounting the external drives?

   iMac (24", 2.8 GHz Intel Core 2 Duo, 2GB RAM, 320 GB HDD) OS X (10.5.4)

2. Király - 4 October 2008

   Nick Naym wrote:

   I have my iMac scheduled (via Energy Saver prefs) to shut down at 3 AM and start up at 8 AM. I'm not sure if I should adhere to such a routine, or simply leave the machine running 24 X 7 (both alternatives have their vocal supporters, and I'd welcome your opinions. :) ).

   But now that the externals are always connected and "on" to enable automatic backups, I'm unsure what happens when the Energy Saver schedule kicks in to shut down the iMac: Does it shut down the system "gracefully," by first dismounting the external drives?

   Yes, but why not just use scheduled sleep instead of shut down? The only time an iMac needs to be shut down is when you need to unplug it. Otherwise, if you are concerned about energy consumption, just put it to sleep. When it wakes up, all your programs, documents, and drives are up and running just as you left them; no need to log back in and relaunch everything. The difference in energy consumption between a sleeping and an off iMac is negligible; it's about half a watt.

   K.

   Lang may your lum reek.

3. Nick Naym - 5 October 2008

   I have my system connected to a UPS, and I vaguely recall (perhaps incorrectly) reading that one should set "sleep" to "never" when the Mac is connected to a UPS. (Unfortunately, I don't recall where I read it, nor the claimed rationale.)

   The
   only time an iMac needs to be shut down is when you need to unplug it. Otherwise, if you are concerned about energy consumption, just put it to sleep. When it wakes up, all your programs, documents, and drives are up and running just as you left them; no need to log back in and relaunch everything. The difference in energy consumption between a sleeping and an off iMac is negligible; it's about half a watt.

   I'm not so concerned about energy consumption, as the difference would be minimal. And the advantage of having everything up and running where I left them is nice, but not a major consideration. The only nagging concern I have is the wear-and-tear on the Mac caused by turning it on and off compared to letting it run continually.

   iMac (24", 2.8 GHz Intel Core 2 Duo, 2GB RAM, 320 GB HDD) OS X (10.5.4)