Which partitions are essential/neccessary for installation. And how big should they be?

just wondering..

The answer to both of your questions is "it depends on your usage". There are two schoools of thought on partitions, and each has its merit. The size of your partition(s) will vary depending on what you will be using the box for. Check out this partition tutorial for more info and reference links: http://www.linuxnewbie.org/nhf/intel...artition.html.

I wonder because:

currently i have
/swap
/usr
/

but when starting up i get /var...... file not found
a lot and then a in the picture above.

but i'll check the tutorial. thanks

It sounds to me like your just missing your /var directory. You don't necessarily *have* to have everything on a different partition. It is good practice so that you can monitor how much each partition is taken and if you need more you just add more(a bit more complex, but easier than redoing a whole drive).

Check your / directory and see if you have /var there. If you created a separate partition for /var, do a 'mount' command and see if it's mounted, if not then manually mount it(to test) and if that works put it in your /etc/fstab.

Just some suggestions.

The most conmmon maybe for a workstation I would say is this:

swap - 100 MB
/boot - 16 MB
/ - the rest of your hard disk usually.

Its good though to make a /home and maybe /tmp as well.

/home can be however big you want or depends on what you will be doing work wise. You can make your /tmp any size you want, but not necessary to go over 500 MB or 1 Gig, again depending on what type of work you will be doing. Its good though to have the /tmp, when your log files and stuff get overloaded for particular reasons, if its on its own partition, once it reaches the limit, it can't affect the rest of your partitions and directories taking up all your space.