topic Minimum Linux File System Sizes in Operating System - Linux

Minimum Linux File System Sizes

AlienRoadShow — Sun, 06 Jul 2003 20:39:03 GMT

Using Red Hat 9

A) What are the O/S file systems?
B) ...their default types?
C) ...and their minimum sizes?
D) What are their recommended sizes?
E) What are their recommended types? (* Just accept Default or something else? *)

For example,

root = xxx mb
swap = xxx mb

Re: Minimum Linux File System Sizes

Balaji N — Mon, 07 Jul 2003 02:49:15 GMT

a tough question. requires more info before this can be answered.

what are you going to do with this.

swap = 2 X RAM.
root = 3-4 GB
a separate /home partition.

run as a mail server / proxy server, etc..

here the main criteria will be /var. so have a huge /var file system.

if you plan to compile from sources, u need to have lot of space in /usr/local. so plan accordingly.

hmmm.. this is what comes to my mind now.

but if u tell what are the services you are going to run, we can tell u more.
-balaji

Re: Minimum Linux File System Sizes

Stuart Browne — Mon, 07 Jul 2003 02:52:55 GMT

Most of these questions depend upon how much space is available, and what kind of installation you are doing (workstation, server, custom).

http://www.redhat.com/docs/manuals/linux/RHL-9-Manual/install-guide/s1-steps-type.html might be helpful to you however.

Re: Minimum Linux File System Sizes

Jerome Henry — Mon, 07 Jul 2003 04:16:49 GMT

Hi Bill,

Adding to friends tips : when I set a machine up, I make several parititons, which will give you informations on some size : say you have 40 GB drive :
/boot : 100MB
swap : twice RAM, as you read on Stuart's link.
/home : 10 GB (why not !)
/tmp : 2 GB (making a partition for it will prevent anybody to flood my system with temp files)
/usr : 10 GB (there you'll install your programs, you can give more spece depending on what you intend to install).
If you install a server, you can also set up a parititon for var, same as /usr.
/ will contain the rest.

Making partitions is intended to physically limit some strategic directory size.

On a personnal standard install, RH9 will make swap partition (type swap, size 2xRAM), /boot partition (type ext2/ext3, 100 MB average), and / (type ext2/ext3, rest of disk), which is default choice and quite OK too.

So, installing, eh ? Cool !

J

Re: Minimum Linux File System Sizes

Hans_8 — Mon, 07 Jul 2003 09:46:21 GMT

Probably an answer you don't like, as there is not clear cut a-priori answer.

It all boils downs to two factors, that only YOU van determine:
a) what do you have (hardware)
b) what do you need (deamons, user programs)

First, let me elliminate one urban legend, like swap is amount of mem, or twice of it.
This is a relic from times where RAM was expensive and limmited.
swap-space is needed if you run more processes than the size of your physical ram. If you have enough RAM and/or limmited the amount of unneeded deamons, just use a tiny swap-space, like 64 MB. (for runaway processes)

The idea of having swap twice the amount of mem, comes from the times when unix systems (HP, SUN) needed an area in which they could dump the contents of the memory in case of a core-dump. And they used the swap area, also to save disk-space. If i were to follow that rule, i would have to define a swapspace of 4GB, No way!!!!
Nowadays, swap-space is a means of last resource, as the system will be awwfull slow (busy swapping in and out). When system incidentily uses swap, no problem, when it constantlu uses swap, it is a sign to either do some tuning, or buy more mem.
Even on our multi gig servers (HP & sun) i only have 512MB swap.

As for the rest, i would suggest the following:
Always make a seperate /boot, about 100MB
This partition should contain all you need to boot, and should in normal situation mounted as read-only, or not mounted at all, just to avoid accidents. If you need it (new kernel or so) mount it manually)

Make a swap of about 128MB
Leave the rest of your disk for /

Install everything YOU REALY NEED, and test your installation very wel.
Do a:
1) du -s /var
2) du -s /usr
3) du -s /home
4) du -s /opt
5) du -s /chroot
6) du -s /tmp
7) du -s /public etc etc etc

If done correctly 2) 4) and 5) won't grow much afterwards, so round it up to the next 100MB, or 80% limmit
Divide the rest of disk space between /, /var, /tmp and /home

With the top-command, you can easily check the use of the sawp-space (or xosview).
/var will grow fast when making a mail server, or logfiles
/home might be big when making a webserver, or for compilations (YES, even for the kernel!)
/tmp could grow big if you dont clear old files
/ should not grow, unless you have unqualified people, log in as root, and doing common mistakes like backing up to a file, instead of the tape-device ;-)), or polluting /root.

If you got theses numbers, re-install the whole lot, using separate partitions.
Use reiserfs for partitions that change much.

It takes some time, but in the end you have a solid configuration....

Hans

Re: Minimum Linux File System Sizes

Balaji N — Mon, 07 Jul 2003 10:12:09 GMT

well said Hans. and thanks for pointing out the swap=2XMem stuff. most of us come from the HP unix background and hence when we think of swap we always think it is swap+dump.

a well worded reply with lots of info.

-balaji

Re: Minimum Linux File System Sizes

AlienRoadShow — Mon, 07 Jul 2003 10:16:00 GMT

Seeeeeee, youuuu guuuyyys.

Quote "... Red Hat 9 will install on any old PC...".

But you forgot to discuss limitations with IDE disk controllers which are typically limited to 512 mb disk sizes but will stretch all the way out to 1 gb.

"...whoopsie daisie..."

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xa2d4506d69a7d711abdc0090277a778c,00.

Re: Minimum Linux File System Sizes

AlienRoadShow — Mon, 07 Jul 2003 10:24:18 GMT

All right, I can still proceed with my 8 gb disk on the AMD K6. I'm just going to have to do some shuffling first since I currently use it for network backups.

Question:

1) du -s /var
2) du -s /usr
3) du -s /home
4) du -s /opt
5) du -s /chroot
6) du -s /tmp
7) du -s /public

...these are sub directories mounted under root and not file systems? Or are they file systems?

Any comments on using the 8 gb disk?

Re: Minimum Linux File System Sizes

Claudio Cilloni — Mon, 07 Jul 2003 10:36:29 GMT

I think 8 GB is a limit for old BIOSes. I remember an old Pentium 100Mhz that couldn't use more than 8 GB of a 20 GB harddisk.
Currently I use two 6 GB disks on a 486, and they work well.
So that 8 GB should be ok.

Ciao
Claudio

Re: Minimum Linux File System Sizes

Hans_8 — Mon, 07 Jul 2003 11:10:52 GMT

Question:

1) du -s /var
2) du -s /usr
3) du -s /home
4) du -s /opt
5) du -s /chroot
6) du -s /tmp
7) du -s /public

...these are sub directories mounted under root and not file systems? Or are they file systems?

Firstly, when trying to determine your need, just make all of them subdirectories under /.

Secondly, if you know how much each of them needs, make them (the ones you need) files systems, mounted on these mount-points.

Anyway, this is done automagically during the installation, at the point of partitioning the disk. (select manually, with disk-druid)
In the first case, just make /boot, swap and /.
In the second case, add all the partitions you need

Hans

Re: Minimum Linux File System Sizes

Caesar_3 — Mon, 07 Jul 2003 19:04:23 GMT

Hello!

For swap = (2..4) * RAM
The limit of 8GB was in the old chipset bios with lilo (i think that if you use RH9 than you use grub and there no problem)

For all the /var /tmp etc.
It depend how you like to made the system
because if /var or /tmp will be with / and /usr and /boot so if you will have to
much temporary files or logs and will take
the all space of disk then your system will down but if they all be difrent partitions that /tmp will be full but no much affect on the whole system.
So check how you will manage this.

Caesar

Re: Minimum Linux File System Sizes

Jerome Henry — Mon, 07 Jul 2003 20:19:20 GMT

Hi Bill,

Your last post about 8 GB is a big pleaseure for me (don't know why, I'm in love with MBR stuff...). This limitations is in old BIOSes and linked to old Cylinder Head Sector adressing to find datas on HD. If you want me to detail more, it will be a (long) pleasure, just ask.

Whatsoever, Linux can overpass this BIOS limitation on recent kernels, by itself of thru instruction in boot loader. RH9 does it by itself on most hard drives (guess what, m$98 can't of course, and Xp often complains !).

More about file systems : as it says, the matter is all about how the system organises it files. In win9x, it's called FAT, and organises with A:, C: an all the stuff you know.
In Linux, it's called ext3 (extended, version 3), and the beginnining of all the system (the C:, in a way), is called /
The only thing that is not under / is the swap, a lot discussed here.
Everything else is under /, in the form of directories ! Even your diskette, your mouse and so on...
What is strange in Unix and Linux, is that everything is a file, even your mouse position : it's stocked in a file, which contents changes all the time. Ext3 file organisation is very interesting to learn (links if required), but notice tha ext 1 was the first attempt, ext 2 the full ehenced working system, and ext3 the same with a journal, remembering datas in case of power shutdown... which makes this system very strong...

J

Re: Minimum Linux File System Sizes

AlienRoadShow — Tue, 08 Jul 2003 15:58:20 GMT

Please refer to the new thread questioning the sleek efficient O/S that is LINUX. (* spoken with a sarcastic tone *)