On 28/01/2006, at 14:34 , Severin Crisp wrote:
I notice, as time goes on, that, despite reboots and all the usual
good housekeeping chores being performed that the available space
on my boot disk (20GB) is slowly reduced. Get Info shows that
10.54GB is used. As part of my backup strategy I periodically
mirror this drive to a 20GB partition on another disk using
SuperDuper. After a recent update, Get Info for this partition
shows only 9.6GB used. Is tthe significant difference just a
fragmentation issue? Do I dare to update the mirror, initialise
the boot disk then mirror the mirror back again? Hopefully I would
then regain this space. With a larger drive the problem would not
matter, at times things get a little cramped with just 20GB and the
lost 1GB would be worth recovering.
Comments please.
Severin Crisp
Hi Severin,
The missing GB is almost certainly down to "virtual memory" or
"swap", which probably doesn't get backed up. When you don't use an
open application for a while, the system 'swaps' that application's
memory to disk. Mac OS X automatically creates a bunch of swapfiles
that contain this memory.
You can have a look by going to /var/vm (Apple-Shift-G in the Finder
to go to the folder), and you'll see a list of files. Whatever you
do, don't attempt to delete them!!!!
The amount of swap space your computer needs depends on usage, and on
the amount of memory you have, but 1 GB is certainly a reasonable
amount in my experience.
cheers,
Josh
