Reiser4 - How To Use It As A Root Partiton My experiances with the bleeding edge FS

This is by no means a complete tutorial,
Simply instruction on how I managed to install gentoo onto a reiser4 partiton.

This is not for beginers! I will assume you have a good understanding of linux, and are capable of more advanced things, such as patching, configureing, compiling and installing a kernel from source without much (if any) instruction.

Currently, no install CD's support the reiser4 fileing system, so we have to do some interesting juggling.

This will describe how i did this with the GNU distro "Gentoo" but there is no reason wh yit could not be performed on any other linux distro.

but first.. a disclaimer..

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PART1:
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The partiton table. we will need to following partitons.

1) OPTIONAL: dual boot partiton (with windowsXP installed ?)
2) boot partiton (100 mb)
3) root partiton (big as possable, minus windows partiton and installer/home partiton sizes)
4) installer_partiton (must be at least 1.5 gig)
5) swap partiton (between 256 mb and 1 gig)

the installer partiton will be used to install the linux that we will use to install linux to the main root partiton.
Think of the installer partiton as a custom made install CD, that supports reiser4.

After the install is complete, we will use this install partiton as a /home/ partiton, so the space is not wasted.

if you keep alot of data in your home partiton, you may want to make it bigger than the minimal 1.5 GIG.

Follow your normal install procedure for your fave distro, select a MINIMAL INSTALL, do not install anything you dont need, no not install X, or KDE, or GNOME, or anything, all you need is a bootable partiton and a compiler ! (gcc must be installed, but NOT KERNEL SOURCE CODE)

When you get to the part of the installer where you must setup the disk, DO NOT use automatic partitons, selct custom partiton, and partiton as described a the start of PART 1.

select the installer partiton as the root partiton for this install, make sure the boot partiton is selected for use, and mount points are all correct.

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PART2:
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by now, you have installed a minmial linux distro (with gcc compiler) to your smaller 1.5 gig installer partiton, and you have sucessfully booted it.

In this Section, we will patch the kernel, and install reiser4 utilities.
Thus allowing us to start using the reiser4 file system.

now, goto kernel.org and download the latest 2.6 vanilla kernel, and the -mm patch set.

unpack the source code to /usr/src/
rename the source directory from linux-2.6.X to linux-2.6.x-mm.
cd into the directory and apply the patch.

gzcat /path/to/mm-patch | patch --dry-run -p1 &&gzcat /path/to/mm-patch | patch  -p1 

if the above command fails to patch the kernel, try with -p0 instead of -p1.
if that doesnt help, you are trying to patch in-ocmpatable versions.. the versions MUST match !

compile the newly patched kernel, somthing like

cp /boot/Config-X ./.configmake oldconfigmake menuconfig# (at this point, select file-systems --> and select Reiser4 as '*' (not M or blank)makemake modules_installcp ./arch/x86_64/boot/bzImage /boot/bzImage-mm

edit /boot/grub/menu.lst to boot bzImage-mm instead of whatever your distro placed by default.

REBOOT !

now install "reiser4progs" package for your distro, gentoo users "emerge reiser4progs".
for different distro's, google for a pre-compiled package, or get thesource code and compile yourself from http://www.namesys.com/v4/v4.html

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PART3:
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Now we are in a reiser4 enabled linux distro, all we need to do now is to place it on a reiser4 partition.

format our main root as reiser4.

mkfs.reiser4 /dev/hdaX

replace X with the partiton number of the main root.

now there is a split, Gentoo users have a choice, all other distro's must go with PART-3A.

In Part 3A, we will simply copy our current root onto the reiser4 partiton.
This is quick, but can be tricky, and will cause 1 or 2 small problems on the first boot, for example lock files that need to be deleted.

The alternative for Gentoo users, is to folow a fresh install on the reiser4 partiton, this is more simple, and problem free, but will take a little longer.

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PART-3A:
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Move our current distro, onto the reiser4 partiton.

make 2 new directory's.

mkdir /reiser4_rootmkdir /source_root

mount the current root to source, and the reiser4 partiton to reiser4 root.

mount /dev/hdaX /reiser4_rootmount /dev/hdaY /source_root

perform the copy.

cp -a /source_root/* /reiser4_root/

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PART-3B:
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start a new install on the reiser4 partiton.

Folow normal gentoo installation except for the part about the kernel install and configure.

when it comes to this, simply copy over the source code, and kernel modules from the installer-partiton.
no need to copy the kernel itself, because we are using a seperate boot partiton remember !

cp -a /lib/modules /mnt/gentoo/lib/cp -a /usr/src/linux-X-mm /mnt/gentoo/usr/src/

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PART-4:
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make the new root partiton bootable.

you will now need to update the partiton numbers to the new root in /boot/brub/menu.lst
make sure to also alter the root=/dev/hdaX parameter on the kernel line !!!
Modify the /reiser4_root/etc/fstab to make the reiser4 partiton root, and make the old root /home/

REBOOT.

format the installer root as reiser4, and edit sftab to make its new mount point /home/.
mount it or reboot before you start to add non-root users.

FINISHED !!!

If you chose option Part 3A, you will expeciance problems dureing the first boot,
this is because of certain lock files which are created, but never deleted, as a bi-product of making a copy of a currently running root partiton.

you will need to hunt these files down, and manually delete them.

ENJOY !
post any qustions you may have here, i will try to anywer them the best i can.

First off...sounds like a pretty good tutorial...I can hardly wait to try it with SuSE, which is the flavor I'm gonna focus on since a job I'm trying to get requires me having knowledge of it.The main question I have is...what is the benifits of having reiser4...I haven't heard of it till now...will have to look into it but real busy so I'll just ask about it and hope someone takes pitty on a busy me and explains it to me....

https://en.wikipedia.org/wiki/Reiser4

In a sentence.... Its an Atomic Journalling FileSystem, that uses Dancing Tree's as opposed to Balanced Tree's, And has the unique ability to support file-system pluggins.

But there are bad points too, read the arguments between mr.Reiser and the kernel hackers on LKML.

Sounds pretty good, but question: Is there any good program to read reiserFS partitions from Windows? That's the only reason I use ext3 ... because explore2fs supports only upto. I tried another program which was linked to on the explore2fs webpage, but it didn't work and I had to reformat the whole thing to ext3. That was around 8 months ago ... is there improved support now?

Lol, of couse not.Microsoft has no inention of implementing any other filesystem other than its own NTFS.even Vanilla Linux doesnt support Reiser4, only the experimental patches such as -nitro -mm and -cko do.NTFS isnt all bad, it does support some features that other FS's dont, Like for example, NTFS tries to place all files required sureing boot close to each other on the physical disk.

Microsoft has no inention of implementing any other filesystem other than its own NTFS.

LOL , I didn't mean M$... for sure, they won't tolerate anything that (they think!) is a threat to their software.

I meant a third party program for windows (like explore2fs) to be able to read ReiserFS partitions from windows.... atleast Reiser3. Is there one available?

Nope.I think ext2 is a relativly simple File System, which might be why a user-space progam like explore2fs can read it.but for reiserFS and especially reiser4 you definatly need to be in kernel space with a driver.I dont think anyone is interested in porting the file systems to the Windows Kernel right now.Also, future plans for Reiser4 seem to be to focussed on the Linux VFS, which obviously doesnt exsist in windows.But hey... ii've got the reiser4 source code if your interested in porting it to win32.. LOL.EDIT: To be honest, the more i read about why Reiser4 is not in the linux kernel, the less i like it.Dont get me wrong, the file system IS impressive, and is very innovative, but from what ive read, Full integration inot the vanilla linux kernel would reuqire changes to the VFS that would inconvinience alot of other file systems. ALSO, the linux kernel hackers claim that once the Reiser team stop maintaining the file system, they will not be able to take over, and support will stop.Reiser, although open source IS afterall a commercial product. It seems the company's motivs are more about getting exposure through linux, than contributing to linux.For now, im enjoying the slight increace in boot speed over reiserFS (verison 3).But I may go on to try XFS or JFS next time i feel like experimenting.As the the -ck kernel patch... im still loving it ! lol.

Well... that's too bad... I guess I'll have to continue using a FAT32 partition for swapping between windows and linux.

But hey... ii've got the reiser4 source code if your interested in porting it to win32.. LOL.

Yea right... .... It'll take me a million years to read up on all that stuff and develop something, coz i'll have to do it from ground up.

But I may go on to try XFS or JFS next time i feel like experimenting.

How many file systems are available for GNU/Linux? I was under the impression that there were only ext and reiser filesystems.

How many file systems are available for GNU/Linux? I was under the impression that there were only ext and reiser filesystems.

ext2 - the origonal linux FS, non journalling
ext3 - journalling version of ext2, ext3 and 2 are the same ehwn journalling is switched off.

Reiser version 3
Reiser version 4 (only available in patched kernels)

JFS - IMB's Journalling File system
XFS - High performance journalling file system by SGI (origonally for IRIX)

MinixFS - for the minix operating system.

A few special purpose encryption / compression file systems,
for example CramFS and SquashFS, used by Knoppix to fit 2 gigs of software onto a 700 mb cd.

and of-course the cd-rom and microsoft file systems.

I think most distro's still default to use Ext3 because its tried, tested, and stable, but its performance is pretty weak.

Ive already made the switch to XFS. not really noticing any difference between XFS and Reiser4... plus XFS s in the vanilla kernel