The following section covers basic installation troubleshooting, such as common problems people have reported. There are also a few questions and answers for people wishing to dual-boot FreeBSD with MS-DOS® or Windows®.
Due to various limitations of the PC architecture, it is impossible for probing to be 100% reliable, however, there are a few things you can do if it fails.
Check the Hardware Notes document for your version of FreeBSD to make sure your hardware is supported.
If your hardware is supported and you still experience
lock-ups or other problems, you will need to build a custom kernel. This will
allow you to add in support for devices which are not present in the
GENERIC kernel. The kernel on the boot disks
is configured assuming that most hardware devices are in their
factory default configuration in terms of IRQs, IO addresses, and
DMA channels. If your hardware has been reconfigured, you will most
likely need to edit the kernel configuration 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. The motherboard firmware may also be referred to as BIOS and most of the motherboard or computer manufactures have a website where the upgrades and upgrade information may be located.
Most manufacturers strongly advise against upgrading the motherboard BIOS unless there is a good reason for doing so, which could possibly be a critical update of sorts. 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 a call to the mount(8)
utility with the appropriate parameters.
A typical line in /etc/fstab is:
The /dos directory 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 MS-DOS® file system looks like:
# mount -t msdosfs /dev/ad0s1 /mntIn this example, the MS-DOS® file system is located on the first
partition of the primary hard disk. Your situation may be different,
check the output from the dmesg, and
mount commands. They should produce enough
information to give an idea of the partition layout.
FreeBSD may number disk slices (that is, MS-DOS® partitions) differently than other operating systems. In particular, extended MS-DOS® partitions are usually given higher slice numbers than primary MS-DOS® partitions. The fdisk(8) utility can help determine which slices belong to FreeBSD and which belong to other operating systems.
NTFS partitions can also be mounted in a similar manner using the mount_ntfs(8) command.
3.11.3.1. | My system hangs while probing hardware during boot, or it behaves strangely during install, or the floppy drive is not probed. |
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 both the
ACPI driver and within system motherboards and BIOS.
The use of ACPI can be disabled by setting
the set hint.acpi.0.disabled="1"This is reset each time the system is booted, so it
is necessary to
add | |
3.11.3.2. | I go to boot from the hard disk for the first time after installing FreeBSD, the kernel loads and probes my hardware, but stops with messages like: changing root device to ad1s1a panic: cannot mount root What is wrong? What can I do? What is this
|
There is a longstanding problem in the case where 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. In the case where the boot disk is not the first disk in the system, FreeBSD can need some help finding it. There are two common situations here, and in both of these cases, you need to tell FreeBSD where the root filesystem is. You do this by specifying the BIOS disk number, the disk type and the FreeBSD disk number for that type. The first situation is where you have two IDE disks,
each configured as the master on their respective IDE
busses, and wish to boot FreeBSD from the second disk. The
BIOS sees these as disk 0 and disk 1, while FreeBSD sees
them as FreeBSD is on BIOS disk 1, of type
1:ad(2,a)kernelNote that if you have 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 you have one or more IDE disks in the system.
In this case, the FreeBSD disk number is lower than the
BIOS disk number. If you have two IDE disks as well as
the SCSI disk, the SCSI disk is BIOS disk 2,
type 2:da(0,a)kernelTo tell FreeBSD that you want to boot from BIOS disk 2,
which is the first SCSI disk in the system. If you only
had one IDE disk, you would use Once you have determined the correct values to use,
you can put the command exactly as you would have typed
it in the | |
3.11.3.3. | I go to boot from the hard disk for the first time
after installing FreeBSD, but the Boot Manager prompt just
prints |
The hard disk geometry was set incorrectly in the partition editor when you installed FreeBSD. Go back into the partition editor and specify the actual geometry of your hard disk. You must reinstall FreeBSD again from the beginning with the correct geometry. If you are failing entirely in figuring out the correct geometry for your machine, here is a tip: Install a small MS-DOS® partition at the beginning of the disk and install FreeBSD after that. The install program will see the MS-DOS® partition and try to infer the correct geometry from it, which usually works. The following tip is no longer recommended, but is left here for reference:
| |
3.11.3.4. | The system finds my ed(4) network card, but I keep getting device timeout errors. |
Your card is probably on a different IRQ from what
is specified in
the Either move the jumper on the card to a hard
configuration setting (altering the kernel settings if
necessary), or specify the IRQ as Another possibility is that your card is at IRQ 9, which is shared by IRQ 2 and frequently a cause of problems (especially when you have a VGA card using IRQ 2!). You should not use IRQ 2 or 9 if at all possible. | |
3.11.3.5. | When sysinstall is used in an X11 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 you already have X11 installed and the default
colors chosen by sysinstall
make text illegible while using xterm(1) or rxvt(1),
add the following to your |
This, and other documents, can be downloaded from ftp://ftp.FreeBSD.org/pub/FreeBSD/doc/
For questions about FreeBSD, read the
documentation before
contacting <questions@FreeBSD.org>.
For questions about this documentation, e-mail <doc@FreeBSD.org>.