Migrate from extX to Reiser4 | HOWTO
 

I struggled with this trouble yesterday, i had my slackware linux 10 installed with / (ext3fs). After reading thread:
What filesystem do you use?
I desided to migrate 2 reiser4 from ext3 without reinstallin my slack =). One of my friends gave me an advise:
I connected another HDD 2 my comp, booted 2 my slack, mounted another hdd 2 /mnt/ibm/, then gave such command, like:
Then, for home/ and so on, but, expect proc/ and mnt/

The next step:
Boot to any livecd (mine was ASP Linux GreenHorn), execute command: mkfsreiser4, then mount another hdd and my ibm(reiser4), but my livecd couldn't mound reiser4 (he didnt know such filesystem). Then i went 2 my friend, compile da kernel 269 with reiserfs support, connected bouth of hdd's and try-ed 2 mount it, mounting my ibm with reiser4 failed =(. I dont know, why, da kernel had to support it =(((. Then i formated my ibm 2 reiser3.6, mounted it with another hdd and copyd all data backward =), then edited /etc/fstab and so on, went home, successfully booted my linux slackware 10, logged in like root, tryed to load X-server, it failed, and there was lots off different troubles, my system became very anstable, and so on, today i wanna try 2 make ext3 and return all my system, like it was +), or reinstall my slack with reiser3.6. This is my question, do smbdy know, how to migrate from reiser3.6 to reiser4? Or how to do this from ext3 to reiser4? Lets disscuss it together =)

copy complete filesystem..
 

Hi,

the approach is basicly correct,
but with a normal cp, some files in your filesystem will not be copied corectly.
that's why most users will use TAR or CPIO for this opperation.

I can never remember the propper tar or cpio options, I allways use
"cp -vrax /boot /usr /var /AND_SO_ON /mnt/BIG_SPACE"

see man cp to read what -vrax does.

It worked for me a couple of tiimes,
never had any problems with it.

Or you can use tar to make sure permissions are preserved :

# cd /
# tar --exclude proc --exclude sys --exclude mnt -cf - . | (cd /mnt/partition; tar xvf -)

And the "Hard drive upgrade mini-howto" is a good place to learn how as well.

But one topic is not soled for now =( How to mount hdd with reiser4 FS, i have da newest kernel, but my mount program say, thet it doesnt know anything about reiser4fs =(

You chose a non-standart filesystem, so to use it, you have to recompile your kernel with reiser4 support.

...exactly. You'll need either the mm, ck, or perhaps love patches to get reiser4 support. When I did it, I used a smaller partition and compiled a base system with the "ck" kernel on it. Then I formatted my deired partition reiser4 and copied my working system to it, leaving the original intact. Then, I added the new boot to my /boot/grub/menu.lst (grub.conf in Gentoo) and changed my new /etc/fstab to reflect the new partitions and rebboted to see if everything was fine. Of course you could also try to make a boot floppy with the reiser4-enabled kernel, but I don't know if reiser4fsprogs would fit on a floppy.

better than copying each top-level directory manually is using the -x option to cp. That's the sort of thing it's there for. :)

This is what you need:
umask 000; cp -avx /bin /boot /etc /mnt/target
This is how Patrick tells to 'migrate' ZipSlack to a hard drive, and YES it's the same for any fs. I've done it many times and it works like a charm.
I'm not sure if reiser4 is supported yet as / fs, but 3.6 is and works great. Do the above and pick a kernel with support for reisersfs compiled in, or boot with an initrd that will load the modules. Use the new mkinitrd pkg for this.

Yes, you have the right idea. It all depends on the kernel used to do the transferring. If the kernel doesn't have reiser4 support built in, it won't recognize it. I've been using the ck patchset until 2.6.8 rev 7. No reiser4 after, so I haven't updated my kernel any newer. To do what is necessary, use the "mm" sources and you'll be fine. Be sure to install reiser4fsprogs so that you can actually format a filesystem and away you go. I've been using it as "/" as soon as it was released to be used publically (as beta, of course). No probs there at all. Its faster and I feel safer knowing a power failure won't likely screw my files.

It ought to be good. I hear that IBM and others gave Hans at least $600,000 as a little 'boost' for r4fs.