So, I'm planning to set up a couple of Linux boxes for learning purposes, and I've read a lot about partitioning and what sizes you should have.
Currently I have 250gb and 300gb disks in each machine, and cosnidered a layout similar to this

/home 150gb
swap 2gb
/ - the rest

I guess this would be sufficient, and would give me some flexibility if I where to reinstall either machine without loosing my personal files, correct?

But, if I where to resize any partitions later on, I guess this would not be a problem?

/A.

You can try setting up LVM but personally I think you leave too much space for / partition

So you want to give at least 100GB to / ? If that is right, I think you should reconsider... Most of my distros have 8 GB for /, and 5 to 6 GB in all for /tmp and /var - and I have found that to be plenty. In fact, unless you install lots of additional stuff, it will even be way too much. The only exceptions I can think of are Suse and Fedora, which do take up more space so gave each 12GB for / and 5 to 6 GB for /var and /tmp.

If you provide way too much space, you may be tempted to install stuff you do not actually need - reasoning something like: I would be wasting space otherwise, so let's install some more. But that's a waste of space and time AND it affects performance...

As for resizing, the possibilites are largely determined by the file system. XFS, for example, can be grown but it cannot be shrunk. Ext2 (and possibly ext3 as well) does have both options. I still prefer xfs, though, because it is way faster.

Unless you have good reasons based on experience, then you only need 2 partitions: / and swap. Home will naturally go into /.

I think that it will be smart, in my case to put /home on a seperat partition since I have a tendency to reinstall machines quite often, and in this case I will not loose any of my private files.

But please help me out here, if I don't use a 100gb or so on / but instead uses 12 gb as one sugestion was, how would it be benefitial to use all my redundant space? What is the normal thing to do?
Would a layout like this be more efficient?

/ - 12gb
/var - 6gb
/tmp - 6 gb
/home - the rest?

It's hard to imagine a situation where you need more than 20GB in "/", and that's including /var and /tmp. So, why not just reserve 20GB for "/" and 2GB for swap and put the rest in /home? We somehow managed on single 15GB drives (or even much less!) for everything until drive prices came down.

I think you misunderstood: I use 5 to 6 GB for var and tmp combined: that is 1.5 to 2 GB for tmp and the rest for var; but the average user could easily reduce those by 25%, if not more; I need them larger simply because I do a lot of programming and I'm not too fond of all the writing and deleting occuring on my / partition.

And yes, you could do without any separate partitions for var and tmp, in which case they would reside under /. There really aren't any absolutes when it comes to partitioning. Choices are made according to needs: servers may benefit from one scheme, development environments from another, office/internet set-ups from yet another, etc. If you adopt the 3-partition scheme (swap, / and /home), I recommend:
for the large majority of distributions:
2GB swap
7-14GB for /
the rest for /home
7GB would be for a "modest" (but already quite rich) system, 14 for one that has it all (office, internet, server, development, multimedia, editing, docs, some large third-party apps, etc etc).

For Suse/Fedora/Sabayon, I recommend adding another 3 GB to / (sabayon would require 12 GB in all at the very least).

Well there are some good suggestions here. The big question is "What kind of computing environment will this be"
jay73 brings a good point to the table in avoiding allot of writing and deleting for programing, Quakeboy points out probably the best scenario for a desktop environment for casual use, gaming and internet. I agree with both except for one detail. Ask yourself if you might want to try other Linux distributions?. If the possibility is there, and you are just setting up a home desktop environment, I would do like Quakeboy, by only having 3 partitions:

1: / partition no bigger than 10GB.
2: swap, no bigger than 2GB,
3: Data partition (not /home) around 100GB will give you lots of room, but allocate it high on the drive so the remaining free space is closer to the start for performance when you add another distro later. User files that are stored in /home should not be in the shared data partition.

If you think you'll be writing and deleting lots, add the separate partitions jay73 suggests. There's really no need to use the entire drive, for two reasons:

1:
Allot of people come here at LQ in a major panic because they want to add another distro, but the tools they were using to re-size the partitions that were too big anyway, and they need to make room to add, screwed things up and they need to recover data, or the tool refuses to re-size the partition, or the computer won't boot after the re-size, etc. etc. etc.
2:
You get better performance in smaller partitions because the read/write heads of the disc are not sweeping across a large part of the drive. Data is usually fetched once and the critical data is placed in the L1 and L2 cache of the processor to improve speed, then some of the not so critical will be placed in ram memory. So the data is best kept towards the far side.

I have a 250GB drive with 7 operating systems right now, two of them are Fedora 6 because I hate taking chances trying something new in the casual use copy, especially when trying to resolve the "dependency hell" thing. And I have a 110GB data partition because I have lots including compressed images of my 6 operating systems. And I always have free space in case I need to test something out, I won't wreck a good copy of an OS, I'll make a quick partition and load an image and screw it up as many times as needed till I figure out how to achieve my goal. The free space will come in handy, it is better to plan ahead than to spend a week or two cruising forums looking for help to bail out of a botched partition re-size situation.

Good idea, Junior Hacker! Personally, I use a separate drive for a "/data" partition and don't keep much of anything permanent on the boot drive. But, to each his own...

Won't be long I'll convert to that scenario also, need more room for working with large dd images. But it involves a 200 km trip to get the drives I'm in need of, also need a larger external for working with the images also, my current external is my backup and it's getting worked over good lately.

JH,
Don't they have ebay up there in Canada? I've bought a couple of drives from an ebayer called btecomputer, who is in Canada.

Might have to look into that
I've been using the same supplier, which is competitive and has allot of shelf space filled with non-boxed drives. I repair computers, and also need a couple 80GB or 120GB drives for stock right now over and above my personal needs. This is bcom computers in Edmonton Alberta, might be related, you never know???
I have never done the ebay thing, but will look into it.