Reiser4 Experiences

I’ve been a long-time user of JFS, but have grown unhappy with it for various reasons. So, I decided to try out XFS. It proved no better than JFS or ReiserFS 3 with data integrity during a crash.

Next step: Reiser4. I’ve been using Reiser4 for the past month or so on three different machines. I must say that I’m quite impressed with it. It is a stellar performer and it also recovers well from crashes. I mount all my filesystems with the nopseudo option, which essentially makes Reiser4 have standard Unix filesystem semantics in every way. I’m very pleased with it so far.

6 thoughts on “Reiser4 Experiences

  1. I am really interested in trying out Reiser4 but am patiently waiting for it to be included in the kernel (even as experimental). Tell me, how is the system different if you have nopseudo turned off?

    Theo

    Reply

    Tomas Ukkonen Reply:

    I just switched my root partition to reiser4 (2.6.11 + patch from namesys).
    AMD64/Pure64 + SATA + software raid1 + reiser4 works with no problems.

    I have had a few issues when setting things up..

    1. Grub doesn’t support reiser4 without patch. I put my kernel to an ext3 partition.
    2. SCSI/LIBATA SATA + MD RAID don’t boottime autodetect md arrays because modules are loaded in wrong order (‘mdadm -A’ works). It’s maybe possible to change the loading order but I just compiled LIBATA SATA support and software raid into kernel.
    3. Reiser4 patch to 2.6.11 incorrectly sets ZLIB_DEFLATE=m. You need to hand edit “.config” to compile it into kernel (‘=y’).
    4. Smartctl doesn’t support SATA drives with a SCSI/LIBATA driver. LIBATA should have support for needed ioctls soon (AFAIK they are waiting for SCSI T10 committee to define numbers for this). It seems that smartmontools will be updated to support those ioctls quickly after LIBATA supports them.

    I haven’t have any real problems with reiser4.
    Everything works normally (I have nopseudo on).

    Reply

  2. That just tells it to disable it “pseudo file” support, which is an extension that no other Linux filesystem has. With pseudo files, you can use specially-named invisible files to adjust metadata about files, such as owner and group. However, a few tools are reported to not get along with them well. I have no need for the pseudo files, so I disable the support, which makes Reiser4 behave with standard Linux semantics (that is, in the same way as all other Linux filesystems).

    Reply

  3. How is the continued stability of Reiser4 for you now? I’m assuming you are continuing to use it? Have you had a crash, and if so what was the result of the subsequent reboot?

    Does reiser4 support data journalling, or only meta-journalling?

    Reply

    jgoerzen Reply:

    It has been very good. I have had an unexpected crash for various reasons, and have noted zero corruption as a result. I’m impressed. Only ext3 in data=ordered has been able to match that.

    I don’t believe that reiser4 supports data journalling, but I’m not certain.

    Reply

  4. Reiser4 uses dancing trees which means that all written data are put aside and after successfully written, the storage tree “dances” to mark these data as the regular file (and the previous content as unused). It is fast and very reliable, but requires disk space. I just wonder if this can be called journal or not (both Wikipedia and Namesys do not).

    Btw. smartmontools supports SATA drives handled by libata, just use smartctl with option “-d ata”.

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *