What level should I keep the battery at?.. And that 1GB image file..

[steve harley]

they whom i call Jim Witte wrote:
> is there a general level should I keep the battery 
> at most of the time - ie, that I shouldn't charge it *above*?  

just plug it in; i'm usually pretty fussy, but in this case i 
think its simpler to just trust Apple's firmware to do more or 
less the right thing; notice that the power circuitry 
automatically stops charging for a while when it reaches full 
charge (the light on the connector goes out); this is an 
optimization for better battery life; worst case you could be 
more productive and have cash on hand for a new battery in a year 
or two

>   Another question regards the rather large-seeming ~1GB image file 
> (compressed I think too!) that the kernal writes out whenever you put 
> and Intel machine computer to sleep?  Is this just a failsafe in case 
> the memory backup power fails

yes, it's called "safe sleep"; there's an extensive discussion 
here, including how to turn it off:

<http://andrewescobar.com/archive/2005/11/11/how-to-safe-sleep-your-mac/>

the one time you need it is the one time  you'll appreciate it; i 
doubt the wear & tear on the drive is significant, though; run 
vm_stat in the shell and look at the faults number; this is the 
number of 4K pages that have been fetched from disk since last 
restart; mine is 280882638, which is ~112 TB of data read from 
disk (in 5 1/2 days); the 2GB which is written for my occasional 
sleeps is a drop in the bucket

some people do say to avoid a lot of wiggling when sleeping, 
though, because you might trigger the sudden motion sensor while 
writing the image

> This makes 
> me think twice before putting the computer to sleep if I'm going to be 
> using it again in say, 20 minutes, because of the drive wear

as you mention, your computer is usually used near a power 
source, so simply plug it in and use a long delay or turn off 
sleep when plugged in (let the screen power off, though, and 
watch your processes to know if something's taking lots of CPU 
while idle); now you aren't writing that 1GB, but your drive will 
still be plenty busy (upping your RAM to 2GB would be a way to 
reduce paging, assuming you dip into VM a lot)

> (I'm 
> paranoid - I've never had a drive crash except for the *really* old 20 
> *MB* Jasmine drive,

live long enough and you'll see more drives crash, trust me