FreeBSD 10.4-RELEASE Errata

FreeBSD/i386 10.4-RELEASE running as a guest operating system on VirtualBox can have a problem with disk I/O access. It depends on some specific hardware configuration and does not depend on a specific version of VirtualBox or host operating system.

It has been reported that instability may be present on virtual machines running on other hypervisors, such as Xen or KVM.

It causes various errors and makes FreeBSD quite unstable. Although the cause is still unclear, disabling unmapped I/O works as a workaround. To disable it, choose Escape to loader prompt in the boot menu and enter the following lines from loader(8) prompt, after an OK:

set vfs.unmapped_buf_allowed=0
boot

Note that the following line has to be added to /boot/loader.conf after a boot. It disables unmapped I/O at every boot:

vfs.unmapped_buf_allowed=0

FreeBSD/i386�10.4-RELEASE installed on ZFS may crash during boot when the ZFS pool mount is attempted while booting an unmodified GENERIC kernel.

As described in /usr/src/UPDATING entry 20121223, rebuilding the kernel with options KSTACK_PAGES=4 has been observed to resolve the boot-time crash. This, however, is not an ideal solution for inclusion in the GENERIC kernel configuration, as increasing KSTACK_PAGES implicitly decreases available usermode threads in an environment that is already resource-starved.

Taking into account the heavy resource requirements of ZFS, in addition to the i386-specific tuning requirements for general workloads, using ZFS with the FreeBSD/i386�GENERIC kernel is strongly discouraged.

If installing FreeBSD/i386 on ZFS, it is possible to configure the system after installation to increase the KSTACK_PAGES.

When prompted by bsdinstall(8) to perform additional post-installation configuration to the system, select [�YES�].

This procedure requires the system sources available locally. If the System source code distribution was not selected during installation, it can be obtained using svnlite:

# mkdir -p /usr/src
# svnlite co https://svn.freebsd.org/base/releng/10.4 /usr/src

Build the kernel-toolchain required to rebuild the kernel:

# make -C /usr/src kernel-toolchain

Next, create a kernel configuration file to increase the KSTACK_PAGES option:

# printf "include GENERIC\noptions KSTACK_PAGES=4\n" > /usr/src/sys/i386/conf/ZFS

Then build and install the ZFS kernel:

# make -C /usr/src buildkernel KERNCONF=ZFS
# make -C /usr/src installkernel KERNCONF=ZFS

Due to an incompatibility between bsdconfig(8) and pkg(8), packages included on the FreeBSD�dvd installer will not be recognized by bsdconfig(8).

To install packages from the dvd1.iso installer, create the /dist target directory, and manually mount the dvd1.iso ISO:

# mkdir -p /dist
# mount -t cd9660 /dev/cd0 /dist

Next, set REPOS_DIR to the path of the repos/ directory within the installer so pkg(8) will use the correct repository metadata.

If using sh(1):

# export REPOS_DIR=/dist/packages/repos

If using csh(1):

# setenv REPOS_DIR /dist/packages/repos

Finally, bootstrap pkg(8) from the ISO, and install required packages:

# pkg bootstrap
# pkg install xorg-server xorg gnome3 [...]

An issue with FreeBSD virtual machines with vagrant was discovered that affects the VirtualBox where the virtual machine will not start on the initial boot invoked with vagrant up.

The issue is due to the virtual machine MAC being unset, as FreeBSD does not provide a default Vagrantfile.

It has been observed, however, that a subsequent invocation of vagrant up will allow the virtual machine to successfully boot, allowing access via vagrant ssh.