This section covers basic installation troubleshooting of common problems. There are also a few questions and answers for people wishing to dual-boot FreeBSD with Windows®.
Due to various limitations of the PC architecture, it is impossible for device probing to be 100% reliable. However, there are a few things to try if it fails.
Check the Hardware Notes document for the version of FreeBSD to make sure the hardware is supported.
If the hardware is supported but still experiences
lock-ups or other problems, build a custom kernel to add in
support for devices which are not present in the
GENERIC kernel. The default kernel
assumes that most hardware devices are in their factory
default configuration in terms of IRQs, I/O addresses, and
DMA channels. If the hardware has been reconfigured, create a
custom kernel configuration file and recompile to tell FreeBSD
where to find things.
It is also possible that a probe for a device not present will cause a later probe for another device that is present to fail. In that case, the probes for the conflicting driver(s) should be disabled.
Some installation problems can be avoided or alleviated by updating the firmware on various hardware components, most notably the motherboard BIOS. Most motherboard and computer manufacturers have a website where upgrade information may be located.
Most manufacturers strongly advise against upgrading the motherboard BIOS unless there is a good reason for doing so, such as a critical update. The upgrade process can go wrong, causing permanent damage to the BIOS chip.
At this time, FreeBSD does not support file systems compressed with the Double Space™ application. Therefore the file system will need to be uncompressed before FreeBSD can access the data. This can be done by running the Compression Agent located in the > > menu.
FreeBSD can support MS-DOS® file systems (sometimes called
FAT file systems). The mount_msdosfs(8) command grafts
such file systems onto the existing directory hierarchy,
allowing the file system's contents to be accessed. The
mount_msdosfs(8) program is not usually invoked directly;
instead, it is called by the system through a line in
/etc/fstab or by using mount(8) with
the appropriate parameters.
A typical line in /etc/fstab
is:
/dev/ad0sN /dos msdosfs rw 0 0
/dos must already exist for this to
work. For details about the format of
/etc/fstab, see fstab(5).
A typical call to mount(8) for a FAT filesystem looks like:
#mount -t msdosfs /dev/ad0s1 /mnt
In this example, the FAT filesystem is located on the first partition of the primary hard disk. The output from dmesg(8) and mount(8) should produce enough information to give an idea of the partition layout.
FreeBSD may number FAT partitions differently than other operating systems. In particular, extended partitions are usually given higher slice numbers than primary partitions. Use fdisk(8) to help determine which slices belong to FreeBSD and which belong to other operating systems.
3.11.3.1. | My system hangs while probing hardware during boot or it behaves strangely during install. |
FreeBSD makes extensive use of the system ACPI service
on the i386, amd64, and ia64 platforms to aid in system
configuration if it is detected during boot.
Unfortunately, some bugs still exist in the ACPI driver
and various system motherboards. The use of ACPI can be
disabled by setting
This is reset each time the system is booted, so it
is necessary to add
| |
3.11.3.2. | When booting from the hard disk for the first time after installing FreeBSD, the kernel loads and probes hardware, but stops with messages like: changing root device to ad1s1a panic: cannot mount root What is wrong? |
This can occur when the boot disk is not the first disk in the system. The BIOS uses a different numbering scheme to FreeBSD, and working out which numbers correspond to which is difficult to get right. If this occurs, tell FreeBSD where the root filesystem is by specifying the BIOS disk number, the disk type, and the FreeBSD disk number for that type. Consider two IDE disks, each configured as the
master on their respective IDE bus, where FreeBSD should be
booted from the second disk. The BIOS sees these as
disk 0 and disk 1, while FreeBSD sees them as
If FreeBSD is on BIOS disk 1, of type
Note that if there is a slave on the primary bus, the above is not necessary and is effectively wrong. The second situation involves booting from a SCSI
disk when there are one or more IDE disks in the system.
In this case, the FreeBSD disk number is lower than the
BIOS disk number. For two IDE disks and a SCSI disk,
where the SCSI disk is BIOS disk 2, type
This tells FreeBSD to boot from BIOS disk 2, which is
the first SCSI disk in the system. If there is only IDE
disk, use Once the correct value to use is determined, put the
command in | |
3.11.3.3. | When booting from the hard disk for the first time
after installing FreeBSD, the Boot Manager prompt just
prints |
The hard disk geometry was set incorrectly in the partition editor when FreeBSD was installed. Go back into the partition editor and specify the actual geometry of the hard disk. FreeBSD must be reinstalled again from the beginning with the correct geometry. For a dedicated FreeBSD system that does not need future compatibility with another operating system, use the entire disk by selecting in the installer's partition editor. | |
3.11.3.4. | The system finds the ed(4) network card but continuously displays device timeout errors. |
The card is probably on a different IRQ from what
is specified in
Either move the jumper on the card to the
configuration setting or specify the IRQ as
Another possibility is that the card is at IRQ 9, which is shared by IRQ 2 and frequently a cause of problems, especially if a VGA card is using IRQ 2. Do not use IRQ 2 or 9 if at all possible. | |
3.11.3.5. | When sysinstall(8) is usedin an Xorg terminal, the yellow font is difficult to read against the light gray background. Is there a way to provide higher contrast for this application? |
If the default colors chosen by sysinstall(8)
make text illegible while using
x11/xterm or
x11/rxvt, add the following to
|
All FreeBSD documents are available for download at http://ftp.FreeBSD.org/pub/FreeBSD/doc/
Questions that are not answered by the
documentation may be
sent to <[email protected]>.
Send questions about this document to <[email protected]>.