What is this file?

[fongster]

Hi all, I found this on my HD while cleaning house:

mach.sym

as well as one called:

mach

The latter is an alias. What about them? Can I just delete them or are they important? Thanks!

 

[monktus]

I'm not too up on UNIX but from what I do know, DON'T delete it! Mach is the kernel that osx is built on and i'm assuming that mach.sym is quite important. Going on older apple systems, osx probably wouldn't let you delete it without making sure you really really wanted to but you never know!

Someone around here will know what your file does exactly but I'm pretty sure that your system would grind to a halt if you trashed it

 

[fongster]

Hi, I will hold off before action. Why I asked about it is that they're alone on the HD folder (not in system folder, etc.) The creation date on them is March 24, 2002--not a date of any significance. I bought the machine and set it up in Oct. 2001. I always run Classic/OS 9.2 except for once I opened OS 10 to verify my DSL connection but can't remember when--maybe not related. The size of the .sym file is 640k.

David

733 G4
OS 9.2.2
640 RAM

 

[monktus]

mach.sym does relate to the kernel but it turns out sym files are used to link shortcuts to another file so I think you're safe to delete them, although the system might create them again. Have a look at:

http://ezine.daemonnews.org/200212/symlink.html
http://www.aelius.com/products/macmachbegone.phtml

Hope that helps

 

[fongster]

Thanks for the info.

 

[michaelsanford]

I really wouldn't delete that...

I'm not entirely sure about this, but I tell you my logic.

Mach is the name of the kernel that Darwin uses (Mac OS X). On most linux systems the current kernel version is referenced with a symlink like "kernel -> /kernel/build/kernel2.34.673" or something. When a new kernel is installed, it just repoints the "kernel" symlink.

This is so that programmers can hard-code various paths into their programs without having to detect the path.

I would surmise that this is the case with /mach. Also note that MacMachBegone makes the files invisible, it does not delete them!

Secondly, if you have only booted OS X once since 2001, why did you install it to begin with? A full install of a Mac OS X system takes around 1.5 to 2.4 gigs I think, whereas you can fit a whole Classic system onto a single CD.

 

[frog_always]

not a good idea to delete those files OS X needs them. I tried that already and OS X gives some kind of error. then you hafta go on the web and look for the Apple care document and startup in single user mode and enter a bunch of commands.

 

[michaelsanford]

More info, this is a snippit from /private/etc/rc (the startup script for OS X multi-user mode)

##
# Create mach symbol file
##

rm -f /mach.sym

sysctl -n kern.symfile

if [ -f /mach.sym ]; then
  rm -f /mach
  ln -s /mach.sym /mach
else
  rm -f /mach
  ln -s /mach_kernel /mach
fi