Currently Being ModeratedAug 3, 2012 5:10 PM (in response to dosers)
I know it's not a permanent solution but as a workaround you can use Caffeine to prevent sleeping. It's available free at the Mac App Store.
Currently Being ModeratedAug 3, 2012 6:33 PM (in response to Therabyte)
Thanks - good app; but that's unfortunately not my issue.
I can easily tell them mac not to go to sleep in energy settings, and that works fine. The issue is, the sleep timer works - all the way up to 'disabling' sleep.
But I don't want the computer to go to sleep unless it's idle. That used to work fine until the Mountain Lion install at which poing sleep seemed to stop caring if programs are actively running when the sleep timer DOES trigger....
Currently Being ModeratedAug 4, 2012 10:29 PM (in response to dosers)
Same problem here too. Started after installing ML.
Currently Being ModeratedAug 11, 2012 2:55 PM (in response to dosers)
I have the same problem. My system goes to sleep while converting video files, streaming videos to my TV etc. It also stops downloading in sleep mode. Very annoying.
Today an upgrade for Unison was available from the app store, it said it fixed dropping connections under 10.8. (Unison can be used to download very large binary files) Installed the update, and as promised it no longer stops downloading in sleep mode. So I'm not sure anymore if this is a bug in ML. Maybe ALL apps need to be updated to take "advantage" of the new power management system in ML. I hope not, but it sure looks like it.
Currently Being ModeratedAug 14, 2012 9:03 PM (in response to Mart65)
According to Ars Technica:
"In Mountain Lion, OS X no longer pays attention to disk activity when deciding if it's OK to put the system to sleep. Instead, Apple recommends that applications make what Apple calls "power assertions" as a way to tell the OS when they're doing some useful work that the system should stay awake for. This policy allows the OS to put the system to sleep the moment there are no applications still holding power assertions to prevent the action."
Apparently the "caffeinate" terminal command can be used in conjunction with specific processs to keep your machine awake until the process completes but it also seems that apps will have to be updated to comply with this new power management protocol. I've noticed the problem with Retrospect 9, HandBrake and RipIt so far...
I have not figured out the terminal commands for using caffeinate with these apps—if anyone has some pointers I would be grateful.
Currently Being ModeratedAug 14, 2012 9:26 PM (in response to Philip Chadwick1)
Yup you could use caffeinate or just open up a file in Quicktime. Just by having Quicktime open it will prevent the system from sleeping which you can verify by typing following command in terminal:
pmset -g assertions
Seems that Apple has gotten pretty aggresive with power managment and apps will have to be updated to deal with it.
Currently Being ModeratedAug 15, 2012 12:08 PM (in response to jologames)
The new power management sounds like a good idea for a laptop. But on a desktop I don't really see the point. Most people will adjust their energy settings, set it to never sleep and end up using more power than before. Adding an option to the energy saver letting you choose what type of computer you're using would have been a better and "greener" choice. At least for now.
Currently Being ModeratedAug 18, 2012 6:56 AM (in response to jologames)
Yes - I agree. It is the Apps that know best whether to allow the sleep timer to be over-ridden or not. But we seem to need to get more developers to realise this.
It affects servers too. My own campaign is to get Logitech to fix the Squeezebox server for the Mac so it prevents sleep while actively serving a Squeezebox music player.
I, for one, am delighted that my Mini now sleeps reliably according to the preference settings. Caffeinate is fine as a workaround for Apps until developers fix them, but it is not any use to the end user for servers like the Logitech Media Server.
Currently Being ModeratedJan 3, 2013 5:36 AM (in response to dosers)
Interesting that they have made these changes that have caused me such mishaps. Funny that apple's aperture 3 software doesn't send the requisite power management requests, as i woke up this morning to find a slideshow export that should have run all night and been completed was asleep as 23%! If they cannot update their own sofware to work under ML without mishap how practical or likely is it that all thir parfties will be able to do so.
Currently Being ModeratedOct 26, 2013 9:04 PM (in response to dosers)
Even worse, not even Apple's OS level software has been adapted, disk utiilty from Mavericks' installer package still goes to sleep while doing a large backup ("crate new disk image from disk"), forcing the user to stay in front of the computer and creating some keyboard or mouse/trackpad activity from time to time.
Currently Being ModeratedJan 22, 2014 3:09 PM (in response to dosers)
I found this thread investigating the same irritating bug, I mean, new Apple design choice. Now I have to sit in front of the Mac to ensure a 50GB data burn completes without losing discs, data or time. Annoying.