I also have partitions containing Windows stuff on /dev/hda, but that's unimportant to this Help File. You may be asking why I picked such weird numbers like 1.49GB and 133MB. Well, actually I didn't. A partition has to begin and end on a cylinder, and since my cylinders are locked in at a certain size, any and all of the partitions I create have to be a multiple of that size, so this was close as I could get to the sizes I requested. I actually wanted 1.5GB, 128MB, 250MB, and 200MB for the BSD, swap, /var, and /tmp partitions respectively. In fact, the 1GB and 2GB partitions aren't exactly 1GB and 2GB either.

For those of you who have an existing installation, you actually have an advantage in this area. You can simply take a look at how much space your directories take and then plan your strategy for partitioning accordingly. To see how much space a specific directory takes on your system, simply issue this command:

du -s -H 

For example, I want to see how much space all of the stuff I have in /usr takes up, so I do this:

du -s -H /usr

and I get back this:

1.6G    /usr

That's the size of all the files in that directory. If you do this as a normal user, you may get a bunch of permissions errors, and you might get a wrong answer, so su to root to do this first.

For those of you who don't have an existing installation, you can either use mine above as an example or ask around (or just wing it, I suppose).

Now, go plan out your partition strategy and then come back and we'll continue. Before going, though, I'd suggest that you leave space at the end of the drive (like I did) for further shifting around. For now I'd only make partitions a little bigger than you think you NEED.

You're back, huh? You better be ready, because here we go... First of all, I'm now going to diverge this Help File into two parts. One is for the people with nothing on their hard drive (or at least nothing they don't mind getting rid of). The other is for those of you who are tweaking an existing installation to accomodate a new Multi-Partition style setup.

Creating a Multi-Partition System with a clean (or soon to be clean) hard drive

You guys have it relatively easy. Basically all you have to do is:

• remove all of the partitions on the hard drive (somehow - if you can get it to mount under Linux, then I have a using fdisk Help File that you will need later anyway)
• create new partitions of the proper size according to your newly created strategy (I have the using fdisk Help File to help you on this)

• create filesystems on those partitions (again, I have an Help File on this as well)
• mess around with /etc/fstab however necessary

And then you are done! You will then be running a multi- partition Linux system. Enjoy it!

Creating a Multi-Partition System with an existing Linux installation already

This is actually not as hard as it sounds. You simply have to learn one new skill and you'll be well on your way - archiving. We use archiving to shrink the data down so that we can create new partitions accordingly, and then we expand the archive onto the new partition and delete it off of the old one.

It's hard to explain in words, and it's easier to explain in an example, so let's do an example.

Well, I already use a multi-partition setup and am happy with it. But, for the sake of this Help File, i'll make it a little more multi-partitioned.

Let's say that one of my partitions was supposed to be mounted at /usr/src (this is an awfully weird and excessively control-freakish choice, so it shouldn't be one of your choices). Let's also say that I wanted to give this a 1GB partition (also a bit high, unless you are a kernel fan).

The first thing I want to do is create a 1GB partition so that I can move all my stuff from /usr/src over there. Let's explore two scenarios:

This actually isn't that likely unless you intentionally left space for that 1GB, because most people just fill up their hard drives. That's understandable, but I tend to leave that space unused now in case something like this happens, because having that free space is a LOT easier to deal with than not.

So, assuming you do have 1GB of unpartitioned space on your drive, all you have to do is this:

Now I'm ready to mount our new partition. The one for my example is /dev/hdb14, though yours may be different. The mount command is:

mount <partition> /mnt/

so, for me that would be:

mount /dev/hdb14 /mnt/src 

There are no real messages indicating success here, so I like to check and make sure that the partition mounted right by doing a df:

[root@half-life ddipaolo]# df
Filesystem           1k-blocks      Used Available Use% Mounted on
/dev/hdb8              1052256    165140    834504  17% /
/dev/hda1              1023312    790016    233296  77% /dos/C
/dev/hda5              4511512   3381464   1130048  75% /dos/D
/dev/hda6              4408896   3674860    734036  83% /dos/E
/dev/hdb5              2038504   1364400    568880  71% /home
/dev/hdb7               202225       247    191536   0% /tmp
/dev/hdb11             2071384   1504896    461264  77% /usr
/dev/hdb12             2071384    125472   1840688   6% /usr/local
/dev/hdb6               248894     12295    223748   5% /var
/dev/hdb14             1035660         4    983048   0% /mnt/src

Where is the full path (and not just the deepeest subdirectory) of the partition you wanted to create. In my example, I would issue:

cp -R /usr/src /mnt

I do this because it automatically copies it into /mnt/src. I'm not exactly sure why it does, but as long as I'm consistent then this works wonderfully.

This copy can take a long time, depending upon how much data you are transferring and how fast your hard drive and system are.

Try not to do too much while the copy is happening, otherwise it might just end up taking longer. But once that is done, you can check that the copy went okay by using the du command again:

[root@half-life src]# cp -Rf /usr/src /mnt
[root@half-life src]# du -s -H /usr/src
316M    /usr/src
[root@half-life src]# du -s -H /mnt/src
316M    /mnt/src

Looks kinda hairy, huh? Well, it's not too bad, really. Just notice that a lot of the things are the same from column to column. Basically, you've got these five (well, six) columns:

Partition - this first one describes what partition is being mounted (or is to be mounted at boot, more precisely)

Mount point - this shows where on the Linux filesystem this partition will be mounted

Filesystem type - specifies what filesystem has been created on that partition or 'auto' to use auto-detection

Options - I've had no use to use anything but defaults, though I've heard of people having issues writing to their mounted Windows partitions as normal users when using "defaults" for their options. I simply never write to my Windows partition except as root, and defaults works fine.

Dumps/Fscks (last two columns) - This has to do with filesystem dumps, fscks, and priorities. For the most part, you can just use the values "1 2" and you'll be fine.

So, like I said, nothing to it. It's basically a cut and paste job. So, to put our new partition with filesystem at /usr/src, let's run down what should go in each column:

Partition - /dev/hdb14 (in my case)
Mount point - /usr/src (again, my case)
Filesystem - ext2
Options - defaults
Dumps - 1 2

So, if you string them all together you get:

/dev/hdb14         /usr/src        ext2    defaults        1 2 

Heck you don't even have to use a text editor to add this one. You can use echo:

echo "/dev/hdb14 /usr/src ext2 defaults 1 2" >> /etc/fstab

Make sure you use >> and not > though. Otherwise you are in serious trouble unless you made a backup.

Well, if your hard drive is just completely full, with no more room for partitions and you really want to try out multiple partitions, then I think it's actually easiest to backup the most important data that you can somehow and then reinstall with the multi-partition strategy. But, there are other ways of doing this:

I like using underscores where the /'s normally go just to make sure that there is no confusion which archive that is when I get them all made. You may also want to omit the "v" because this will print out a lot of information. Also, obviously, substitute the filename (mine was _usr_src.tar.gz, yours should end in .tar.gz as well, though it's not compulsory), and directory (mine was /usr/src) that is appropriate to your archiving.

So, once I do this for ALL the partitions on my scheme, I move them to my storage area (for me, it's my Windows partition).

Then, I pop in my bootdisk and reboot.

Once everything comes up on the bootdisk, I make ABSOLUTELY SURE that I:

a - can access the files I just moved
b - that I have BACKED UP all my important stuff!

Once I have verifired both a and b, as well as verifying that I really really really want to go to this multi-partition setup, then I go ahead and fire up fdisk and remove all my Linux partitions and add new ones according to my strategy (see my fdisk Help File if necessary for a refresher). Then, if I have room for them all on one of my partitions, I copy all those archives down onto a Linux partition (notice I said copy and not move).

Once they are copied down to the Linux partition, I feel much much better. The next thing to do is to mount the partitions according to plan. That was discussed in section 3 above, so refer to that section and then come back here. You need to do this for all the partitions (or, at least you might as well do it for all of them right now). Then, you need to inflate the archives. If you did them the way I told you, this should be very easy. First, make sure the archive is in the root (/) directory. If it's not on that partition right now, move it there. Then, simply issue practically the same tar command:

tar xvfz <filename>.tar.gz

or, in this case it'd be:

tar xvfz _usr_src.tar.gz

At this point, a list of files should go flying by - these are the files being inflated. They should also all have a leading path of some sort - like mine is /usr/src - unless, of course, this is your root (/) partition archive (which I normally name _.tar.gz, even though it's odd... it's consistent). Once you have successfully inflated each of the archives, you may delete them all from your Linux partitions (and from those partitions only), but do NOT delete them on your storage media just yet, we may need them later.

The next thing you need to do is configure your /etc/fstab so that things work right on startup. See section 5 above on that. Once that is done, remove the bootdisk and reboot, and (if you believe in doing so) pray. If things DO go wrong and it won't boot correctly, there's not much lost in doing a reinstall. You still have your partition scheme and your archives somewhere, right? Well, reinstall, and simply inflate the archives on top of the freshly installed files and see if that works. If this is done correctly, it should not hose your system, though I won't say that I have never hosed my system by doing things like this.

Well, with any luck, you have just set up your system for its new multi-partition setup. If things didn't go perfectly, I apologize. Otherwise, have fun!