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inscrewtable

macrumors 68000
Original poster
Oct 9, 2010
1,656
402
I am aware that in the past 20% free disk space was recommended for the happy running of OSX, however now that HD's have gotten very very large and also that we are up to 10.8.2 which seems to be a bit different from how it manages virtual memory than was 10.5, I'd like to check.

I have a 2011 iMac with a 2TB HD running 10.8 and I currently have 440GB free, while that is close to the 20% that used to be recommended it still seems like a lot to leave free.

But I do note that 10.8.2 does seem to use a massive amount of virtual memory so I was wondering what would be the minimum amount of free space I should leave without compromising the running of the OS (with regard to self-defragmenting) or the hardware.

Should I stick with the 400GB free or am I safe to go down to 200GB free or even 100?

In case it is relevant I am not running Time Machine as I do a separate bootable backup

thanks
 
I am aware that in the past 20% free disk space was recommended for the happy running of OSX, however now that HD's have gotten very very large and also that we are up to 10.8.2 which seems to be a bit different from how it manages virtual memory than was 10.5, I'd like to check.

I have a 2011 iMac with a 2TB HD running 10.8 and I currently have 440GB free, while that is close to the 20% that used to be recommended it still seems like a lot to leave free.

But I do note that 10.8.2 does seem to use a massive amount of virtual memory so I was wondering what would be the minimum amount of free space I should leave without compromising the running of the OS (with regard to self-defragmenting) or the hardware.

Should I stick with the 400GB free or am I safe to go down to 200GB free or even 100?

In case it is relevant I am not running Time Machine as I do a separate bootable backup

thanks

I don't think you are looking at any sort of problem here. You don't need hundreds of gigabytes of free space. I've run OSX on a machine with a full HDD and I didn't notice until I tried to save a large file. I was somewhat embarrassed and had to spend some time deleting stuff I didn't need any more but there were no ill effects.

On Linux, you create a separate swap partition. On OSX, I would think the OS swaps directly to disk. Say you have 16 GB of RAM. You would need about 16 GB of swap space. More seems like quite a waste. So your question about whether 400 GB is enough seems silly when it is quite easy to run OS X on a 256 GB disk with only a dozen GB free. Still, I worry about why you have so much stuff to begin with. This would imply that any Time Machine backup of your stuff is over 2 TB now, right? Ouch. I'd much rather keep bulky files like movies, photos and music on an external drive and back them up by "file copy mirroring".

I'm typing this on a MBP with 750 GB drive which has 550 GB free and I'm looking for ways to get rid of some stuff so I can squeeze onto a sub $200 256 GB SSD rather than spring $400 for a 512 GB Crucial M4.
 
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