Testing out FreeBSD 8.0-RC2

Those who haven’t read about my 8.0-RC1 experience should do so first:

Basically, my experience with 8.0-RC2 was identical to that of RC1, except some of the bugs/issues I experienced are now gone (hooray!). Fixes/improvements which I noticed are below:

  • The issue I experienced with the Boot Manager selection phase of installation has been fixed. Also, Standard is now the default option (first choice).
  • The geometry does not match label problem has been addressed by fixing the FreeBSD slice editor in sysinstall/sade; see below.
  • libdisk has been modified to work properly with GEOM; the FreeBSD slice editor links to libdisk — thanks to Randi Harper for tracking this commit down! Commonly when installing FreeBSD on a box, people go into the slice editor and press “a” to use the entire disk. Previously, users would end up with a disk where the first 63 sectors were unused (probably for the PBR/MBR and overall alignment), then the FreeBSD slice, and a third “unused” portion of the disk (which, if I remember correctly, was done solely for alignment reasons). Example:
    Offset       Size(ST)        End     Name  PType       Desc  Subtype    Flags
             0         63         62        -     12     unused        0
            63  390716802  390716864    ad8s1      8    freebsd      165    A
     390716865       5103  390721967        -     12     unused        0

    Note the highlighted line. Now, starting with RC2, this is what you’ll see:

    Offset       Size(ST)        End     Name  PType       Desc  Subtype    Flags
             0         63         62        -     12     unused        0
            63  390721905  390721967    ad8s1      8    freebsd      165    A

    Note the lack of that highlighted line (the “unused” section).

    Sadly, this also means people will need to reinstall FreeBSD (specifically, deleting the slice and re-creating it) to benefit from this. As far as I know, you can’t fix this without a full reinstallation.

  • The EOF issue for ttys (re: ^D being shown) has been fixed and committed to CURRENT (FreeBSD 9.0), but hasn’t been MFC’d to RELENG_8 yet. Yes, it’s scheduled to be (in about 2 weeks). Big thanks to Ed Schouten for fixing this!
  • There were some ZFS commits which happened between RC1 and RC2 which may indicate that the ARC exhausting all available kmem is no longer possible. I have not been able to confirm/deny whether this fix works, but looking at the code, it may be sufficient. I’d need to get in touch with Kip Macy to confirm/deny.

Issues that are still pending:

  • bsdlabel still behaves incorrectly (“Class not found”). Instead, users should use gpart to write the bootstraps as follows: gpart bootcode [disk], where [disk] is ad4 or similar. Note that you pick the disk itself now, not the slice like in bsdlabel (unless you were using dangerously dedicated disks :-) ).
  • The ZFS notice pertaining to vfs.zfs.prefetch_disable when the system has less than 4GB RAM available has been re-worded again, but still is vague/unclear. A little bit of ego here — the person committing these changes should really consider changing the message to what I proposed.
  • I still haven’t received a reply to my request for clarification on ZFS stabilisation. Is /boot/loader.conf tuning for kmem-related parameters still required? We still need an official statement on this matter.

I also want to take a moment to send a shout-out to John Baldwin, who has been working incredibly hard on the FreeBSD kernel (specifically VM and ACPI) over the past 4 weeks. John, I’ve seen/followed your commits, and I appreciate the improvements! Thank you!