Most of the documentation is a snapshot of the old Namesys site (archive.org, 2007-09-29).
There was also a Reiser4 Wiki (archive.org, 2007-07-06) once on pub.namesys.com.
Reiser4 development appears to have stalled and ReiserFS is deprecated and scheduled to be removed from mainline Linux in 2025.
FAQ/potato part
I succeeded with little trouble in installing Debian potato with ReiserFS as its root partition. I'll summarise the process for those who are interested.
I created a boot floppy with a kernel supporting ReiserFS and a root floppy with the mkfs.reiserfs on it. I did find it useful to mount and umount each mkfs-ed partition, since it takes a good deal of time for the first install.
I rebooted using my ReiserFS kernel but the potato root disk. I then installed as normal, with the following exceptions:
- The Debian install procedure does not know about ReiserFS, so I had to mount the various filesystems manually. Then I picked another item from the menu. The first time this fails since the install program does not know the root partition is mounted (on target), but then it figures this out and proceeds normally.
- The install procedure writes a correct /etc/fstab for all partitions except the root, to which it incorrectly gives a file type of ext2. Simply edit this before rebooting.
- The install procedure installs a kernel which knows nothing about ReiserFS. I just replaced this with my kernel, and put the appropriate modules in /lib/modules.
- I use GRuB instead of Debian's mbr or LILO, so I simply dpkg --delete mbr and install grub before rebooting the first time. The latest GRuB supports ReiserFS.
I chose to do this because I had a machine with a hardware fault which needed frequent rebooting. This of course led to a number of corruption problems even with ReiserFS, but we eventually ran the problem down to faulty sims (thanks to memcheck-86). To avoid possible problems, I've reinstalled again, again using ReiserFS. The machine has run beautifully ever since.
I've been digging through the mailing list, and seen occasional remarks about FAQs, but no pointer to a reiserfs FAQ. Can I presume none exists at this time?