`
`Frequently Asked Questions for FreeBSD 2.X, 3.X and 4.X
`
`JUN
`
`200
`
`Next
`
`Prev
`
`Nik Clayton
`
`3.1. Which file do I download to get FreeBSD?
`3.2. What do I do if the floppy images does not fit on a single floppy?
`3.3. Where are the instructions for installing FreeBSD?
`3.4. What do I need in order to run FreeBSD?
`3.5. I have only 4 MB of RAM. Can I install FreeBSD?
`3.6. How can I make my own custom install floppy?
`3.7. Can I have more than one operating system on my PC?
`3.8. Can Windows 95/98 co-exist with FreeBSD?
`3.9. Windows 95/98 killed my boot manager! How do I get it back?
`3.10. My A, T, or X series IBM Thinkpad locks up when I first booted up my FreeBSD installation. How can I solve this?
`3.11. Can I install on a disk with bad blocks?
`3.12. I have just upgraded from 3.X to 4.X, and my first boot failed with ``bad sector table not supported''
`3.13. How do I tell if a drive has bad144 information on it before I try to upgrade to FreeBSD 4.0 and it fails?
`3.14. How do I remove bad144 from my pre-4.X system so I can upgrade safely?
`3.15. Strange things happen when I boot the install floppy! What is happening?
`3.16. I booted from my ATAPI CDROM, but the install program says no CDROM is found. Where did it go?
`3.17. Why can I not install from tape?
`3.18. Can I install on my laptop over PLIP (Parallel Line IP)?
`3.19. Which geometry should I use for a disk drive?
`3.20. Are there any restrictions on how I divide the disk up?
`3.21. Is FreeBSD compatible with any disk managers?
`3.22. When I boot FreeBSD I get ``Missing Operating System''. What is happening?
`3.23. Why can I not get past the boot manager's F? prompt?
`3.24. Do I need to install the complete sources?
`3.25. Do I need to build a kernel?
`3.26. Should I use DES passwords, or MD5, and how do I specify which form my users receive?
`3.27. Why does the boot floppy start, but hang at the Probing Devices... screen?
`3.28. Why do I get a ``panic: can't mount root'' error when rebooting the system after installation?
`3.29. What are the limits for memory?
`3.30. What are the limits for ffs filesystems?
`3.31. Why do I get an error message, ``archsw.readin.failed'' after compiling and booting a new kernel?
`3.32. How do I upgrade from 3.X -> 4.X?
`3.33. What are these ``security profiles''?
`
`3.1. Which file do I download to get FreeBSD?
`Prior to release 3.1, you only needed one floppy image to install FreeBSD, namely floppies/boot.flp. However, since
`release 3.1 the Project has added out-of-the-box support for a wide variety of hardware, which takes up more space. For 3.x
`and later you need two floppy images: floppies/kernel.flp and floppies/mfsroot.flp. These images need to be copied
`onto floppies by tools like fdimage or dd(1).
`If you need to download the distributions yourself (for a DOS filesystem install, for instance), below are some
`recommendations for distributions to grab:
`bin/
`manpages/
`compat*/
`doc/
`src/ssys.*
`
`1 of 8
`
`CSCO-1035
`Page 1 of 8
`
`
`
`https://web.archive.org/web/20020404064240/http://www.freebsd.org:80/doc/en_US.ISO8859-1/books/faq/install.html
`
`JUN
`
`200
`
`Full instructions on this procedure and a little bit more about installation issues in general can be found in the Handbook
`entry on installing FreeBSD.
`3.2. What do I do if the floppy images does not fit on a single floppy?
`A 3.5 inch (1.44MB) floppy can accommodate 1474560 bytes of data. The boot image is exactly 1474560 bytes in size.
`Common mistakes when preparing the boot floppy are:
`Not downloading the floppy image in binary mode when using FTP.
`Some FTP clients default their transfer mode to ascii and attempt to change any end-of-line characters received
`to match the conventions used by the client's system. This will almost invariably corrupt the boot image. Check
`the size of the downloaded boot image: if it is not exactly that on the server, then the download process is
`suspect.
`To workaround: type binary at the FTP command prompt after getting connected to the server and before
`starting the download of the image.
`Using the DOS copy command (or equivalent GUI tool) to transfer the boot image to floppy.
`Programs like copy will not work as the boot image has been created to be booted into directly. The image has
`the complete content of the floppy, track for track, and is not meant to be placed on the floppy as a regular file.
`You have to transfer it to the floppy ``raw'', using the low-level tools (e.g. fdimage or rawrite) described in the
`installation guide to FreeBSD.
`3.3. Where are the instructions for installing FreeBSD?
`Installation instructions can be found in the Handbook entry on installing FreeBSD.
`3.4. What do I need in order to run FreeBSD?
`You will need a 386 or better PC, with 5 MB or more of RAM and at least 60 MB of hard disk space. It can run with a low
`end MDA graphics card but to run X11R6, a VGA or better video card is needed.
`See also Chapter 4
`3.5. I have only 4 MB of RAM. Can I install FreeBSD?
`FreeBSD 2.1.7 was the last version of FreeBSD that could be installed on a 4MB system. FreeBSD 2.2 and later needs at
`least 5MB to install on a new system.
`All versions of FreeBSD will run in 4MB of RAM, they just cannot run the installation program in 4MB. You can add extra
`memory for the install process, if you like, and then after the system is up and running, go back to 4MB. Or you could swap
`your disk into a system which has >4MB, install onto the disk and then swap it back.
`FreeBSD 2.1.7 will not install with 640 kB base + 3 MB extended memory. If your motherboard can remap some of the
```lost'' memory out of the 640kB to 1MB region, then you may still be able to get FreeBSD 2.1.7 up. Try to go into your
`BIOS setup and look for a ``remap'' option. Enable it. You may also have to disable ROM shadowing. It may be easier to get
`4 more MB just for the install. Build a custom kernel with only the options you need and then remove the 4MB out. You can
`also install 2.0.5 and then upgrade your system to 2.1.7 with the ``upgrade'' option of the 2.1.7 installation program.
`After the installation, if you build a custom kernel, it will run in 4 MB. Someone has even successfully booted with 2 MB,
`although the system was almost unusable.
`3.6. How can I make my own custom install floppy?
`Currently there is no way to just make a custom install floppy. You have to cut a whole new release, which will include your
`install floppy.
`To make a custom release, follow the instructions in the Release Engineering article.
`3.7. Can I have more than one operating system on my PC?
`Have a look at the multi-OS page.
`3.8. Can Windows 95/98 co-exist with FreeBSD?
`Install Windows 95/98 first, after that FreeBSD. FreeBSD's boot manager will then manage to boot Win95/98 and FreeBSD.
`If you install Windows 95/98 second, it will boorishly overwrite your boot manager without even asking. If that happens,
`see the next section.
`3.9. Windows 95/98 killed my boot manager! How do I get it back?
`You can reinstall the boot manager FreeBSD comes with in one of three ways:
`
`2 of 8
`
`Page 2 of 8
`
`
`
`https://web.archive.org/web/20020404064240/http://www.freebsd.org:80/doc/en_US.ISO8859-1/books/faq/install.html
`
`200
`
`Running DOS, go into the tools/ directory of your FreeBSD distribution and look for bootinst.exe. You run it
`JUN
`like so:
`...\TOOLS> bootinst.exe boot.bin
`and the boot manager will be reinstalled.
`Boot the FreeBSD boot floppy again and go to the Custom installation menu item. Choose Partition. Select the
`drive which used to contain your boot manager (likely the first one) and when you come to the partition editor
`for it, as the very first thing (e.g. do not make any changes) select (W)rite. This will ask for confirmation, say
`yes, and when you get the Boot Manager selection prompt, be sure to select ``Boot Manager''. This will re-write
`the boot manager to disk. Now quit out of the installation menu and reboot off the hard disk as normal.
`Boot the FreeBSD boot floppy (or CDROM) and choose the ``Fixit'' menu item. Select either the Fixit floppy or
`CDROM #2 (the ``live'' file system option) as appropriate and enter the fixit shell. Then execute the following
`command:
`Fixit# fdisk -B -b /boot/boot0 bootdevice
`substituting bootdevice for your real boot device such as ad0 (first IDE disk), ad4 (first IDE disk on auxiliary
`controller), da0 (first SCSI disk), etc.
`3.10. My A, T, or X series IBM Thinkpad locks up when I first booted up my FreeBSD installation. How can I solve this?
`A bug in early revisions of IBM's BIOS on these machines mistakenly identifies the FreeBSD partition as a potential FAT
`suspend-to-disk partition. When the BIOS tries to parse the FreeBSD partition it hangs.
`According to IBM[1], the following model/BIOS release numbers incorporate the fix.
`Model BIOS revision
`T20
`IYET49WW or later
`T21 KZET22WW or later
`A20p IVET62WW or later
`A20m IWET54WW or later
`A21p KYET27WW or later
`A21m KXET24WW or later
`A21e KUET30WW
`
`It has been reported that later IBM BIOS revisions may have reintroduced the bug. This message from Jacques Vidrine to
`the FreeBSD laptop computer mailing list <freebsd-mobile@FreeBSD.org> describes a procedure which may work if your
`newer IBM laptop does not boot FreeBSD properly, and you can upgrade or downgrade the BIOS..
`If you have an earlier BIOS, and upgrading is not an option a workaround is to install FreeBSD, change the partition ID
`FreeBSD uses, and install new boot blocks that can handle the different partition ID.
`First, you will need to restore the machine to a state where it can get through its self-test screen. Doing this requires
`powering up the machine without letting it find a FreeBSD partition on its primary disk. One way is to remove the hard disk
`and temporarily move it to an older ThinkPad (such as a ThinkPad 600) or a desktop PC with an appropriate conversion
`cable. Once it is there, you can delete the FreeBSD partition and move the hard disk back. The ThinkPad should now be in a
`bootable state again.
`With the machine functional again, you can use the workaround procedure described here to get a working FreeBSD
`installation.
`1.
`
`Download boot1 and boot2 from http://people.FreeBSD.org/~bmah/ThinkPad/. Put these files somewhere you
`will be able to retrieve them later.
`Install FreeBSD as normal on to the ThinkPad. Do not use Dangerously Dedicated mode. Do not reboot when
`the install has finished.
`Either switch to the ``Emergency Holographic Shell'' (ALT+F4) or start a ``fixit'' shell.
`Use fdisk(8) to change the FreeBSD partition ID from 165 to 166 (this is the type used by OpenBSD).
`Bring the boot1 and boot2 files to the local filesystem.
`Use disklabel(8) to write boot1 and boot2 to your FreeBSD slice.
`# disklabel -B -b boot1 -s boot2 ad0sn
`n is the number of the slice where you installed FreeBSD.
`
`2.
`
`3.
`4.
`5.
`6.
`
`3 of 8
`
`Page 3 of 8
`
`
`
`https://web.archive.org/web/20020404064240/http://www.freebsd.org:80/doc/en_US.ISO8859-1/books/faq/install.html
`
`200
`
`Reboot. At the boot prompt you will be given the option of booting OpenBSD. This will actually boot FreeBSD.
`7.
`JUN
`Getting this to work in the case where you want to dual boot OpenBSD and FreeBSD on the same laptop is left as an
`exercise for the reader.
`3.11. Can I install on a disk with bad blocks?
`Prior to 3.0, FreeBSD included a utility known as bad144, which automatically remapped bad blocks. Because modern IDE
`drives perform this function themselves, bad144 has been removed from the FreeBSD source tree. If you wish to install
`FreeBSD 3.0 or later, we strongly suggest you purchase a newer disk drive. If you do not wish to do this, you must run
`FreeBSD 2.x.
`If you are seeing bad block errors with a modern IDE drive, chances are the drive is going to die very soon (the drive's
`internal remapping functions are no longer sufficient to fix the bad blocks, which means the disk is heavily corrupted); we
`suggest you buy a new hard drive.
`If you have a SCSI drive with bad blocks, see this answer.
`3.12. I have just upgraded from 3.X to 4.X, and my first boot failed with ``bad sector table not supported''
`FreeBSD 3.X and earlier supported bad144, which automatically remapped bad blocks. FreeBSD 4.X and later do not
`support this, as modern IDE drives include this functionality. See this question for more information.
`To fix this after an upgrade, you need to physically place the drive in a working system and use disklabel(8) as discussed in
`the following questions.
`3.13. How do I tell if a drive has bad144 information on it before I try to upgrade to FreeBSD 4.0 and it fails?
`Use disklabel(8) for this. disklabel -r drive device will give you the contents of your disk label. Look for a flags field.
`If you see flags: badsect, this drive is using bad144. For example, the following drive has bad144 enabled.:
`# disklabel -r wd0
` # /dev/rwd0c:
` type: ESDI
` disk: wd0s1
` label:
` flags: badsect
` bytes/sector: 512
` sectors/track: 63
`3.14. How do I remove bad144 from my pre-4.X system so I can upgrade safely?
`Use disklabel -e -rwd0 to edit the disklabel in place. Just remove the word badsect from the flags field, save, and exit.
`The bad144 file will still take up some space on your drive, but the disk itself will be usable.
`We still recommend you purchase a new disk if you have a large number of bad blocks.
`3.15. Strange things happen when I boot the install floppy! What is happening?
`If you are seeing things like the machine grinding to a halt or spontaneously rebooting when you try to boot the install
`floppy, here are three questions to ask yourself:-
`1.
`Did you use a new, freshly-formatted, error-free floppy (preferably a brand-new one straight out of the box, as
`opposed to the magazine cover disk that has been lying under the bed for the last three years)?
`Did you download the floppy image in binary (or image) mode? (do not be embarrassed, even the best of us
`have accidentally downloaded a binary file in ASCII mode at least once!)
`If you are using Windows95 or Win98 did you run fdimage or rawrite in pure DOS mode? These operating
`systems can interfere with programs that write directly to hardware, which the disk creation program does; even
`running it inside a DOS shell in the GUI can cause this problem.
`There have also been reports of Netscape causing problems when downloading the boot floppy, so it is probably best to use
`a different FTP client if you can.
`3.16. I booted from my ATAPI CDROM, but the install program says no CDROM is found. Where did it go?
`The usual cause of this problem is a mis-configured CDROM drive. Many PCs now ship with the CDROM as the slave
`device on the secondary IDE controller, with no master device on that controller. This is illegal according to the ATAPI
`specification, but Windows plays fast and loose with the specification, and the BIOS ignores it when booting. This is why
`the BIOS was able to see the CDROM to boot from it, but why FreeBSD cannot see it to complete the install.
`Reconfigure your system so that the CDROM is either the master device on the IDE controller it is attached to, or make sure
`that it is the slave on an IDE controller that also has a master device.
`3.17. Why can I not install from tape?
`
`2.
`
`3.
`
`4 of 8
`
`Page 4 of 8
`
`
`
`https://web.archive.org/web/20020404064240/http://www.freebsd.org:80/doc/en_US.ISO8859-1/books/faq/install.html
`
`If you are installing 2.1.7R from tape, you must create the tape using a tar blocksize of 10 (5120 bytes). The default tar
`JUN
`blocksize is 20 (10240 bytes), and tapes created using this default size cannot be used to install 2.1.7R; with these tapes, you
`will get an error that com
`200
`3.18. Can I install on my laptop over PLIP (Parallel Line IP)?
`Yes. Use a standard Laplink cable. If necessary, you can check out the PLIP section of the Handbook for details on parallel
`port networking.
`If you are running FreeBSD 3.X or earlier, also look at the Mobile Computing page.
`3.19. Which geometry should I use for a disk drive?
`Note: By the ``geometry'' of a disk, we mean the number of cylinders, heads and sectors/track on a disk. We will refer to this
`as C/H/S for convenience. This is how the PC's BIOS works out which area on a disk to read/write from.
`
`This causes a lot of confusion among new system administrators. First of all, the physical geometry of a SCSI drive is totally
`irrelevant, as FreeBSD works in term of disk blocks. In fact, there is no such thing as ``the'' physical geometry, as the sector
`density varies across the disk. What manufacturers claim is the ``physical geometry'' is usually the geometry that they have
`determined wastes the least space. For IDE disks, FreeBSD does work in terms of C/H/S, but all modern drives internally
`convert this into block references.
`All that matters is the logical geometry. This is the answer that the BIOS gets when it asks the drive ``what is your
`geometry?'' It then uses this geometry to access the disk. As FreeBSD uses the BIOS when booting, it is very important to
`get this right. In particular, if you have more than one operating system on a disk, they must all agree on the geometry.
`Otherwise you will have serious problems booting!
`For SCSI disks, the geometry to use depends on whether extended translation support is turned on in your controller (this is
`often referred to as ``support for DOS disks >1GB'' or something similar). If it is turned off, then use N cylinders, 64 heads
`and 32 sectors/track, where N is the capacity of the disk in MB. For example, a 2GB disk should pretend to have 2048
`cylinders, 64 heads and 32 sectors/track.
`If it is turned on (it is often supplied this way to get around certain limitations in MSDOS) and the disk capacity is more
`than 1GB, use M cylinders, 63 sectors per track (not 64), and 255 heads, where 'M' is the disk capacity in MB divided by
`7.844238 (!). So our example 2GB drive would have 261 cylinders, 63 sectors per track and 255 heads.
`If you are not sure about this, or FreeBSD fails to detect the geometry correctly during installation, the simplest way around
`this is usually to create a small DOS partition on the disk. The BIOS should then detect the correct geometry, and you can
`always remove the DOS partition in the partition editor if you do not want to keep it. You might want to leave it around for
`programming network cards and the like, however.
`Alternatively, there is a freely available utility distributed with FreeBSD called pfdisk.exe. You can find it in the tools
`subdirectory on the FreeBSD CDROM or on the various FreeBSD FTP sites. This program can be used to work out what
`geometry the other operating systems on the disk are using. You can then enter this geometry in the partition editor.
`3.20. Are there any restrictions on how I divide the disk up?
`Yes. You must make sure that your root partition is below 1024 cylinders so the BIOS can boot the kernel from it. (Note that
`this is a limitation in the PC's BIOS, not FreeBSD).
`For a SCSI drive, this will normally imply that the root partition will be in the first 1024MB (or in the first 4096MB if
`extended translation is turned on - see previous question). For IDE, the corresponding figure is 504MB.
`3.21. Is FreeBSD compatible with any disk managers?
`FreeBSD recognizes the Ontrack Disk Manager and makes allowances for it. Other disk managers are not supported.
`If you just want to use the disk with FreeBSD you do not need a disk manager. Just configure the disk for as much space as
`the BIOS can deal with (usually 504 megabytes), and FreeBSD should figure out how much space you really have. If you
`are using an old disk with an MFM controller, you may need to explicitly tell FreeBSD how many cylinders to use.
`If you want to use the disk with FreeBSD and another operating system, you may be able to do without a disk manager: just
`make sure the FreeBSD boot partition and the slice for the other operating system are in the first 1024 cylinders. If you are
`reasonably careful, a 20 megabyte boot partition should be plenty.
`3.22. When I boot FreeBSD I get ``Missing Operating System''. What is happening?
`This is classically a case of FreeBSD and DOS or some other OS conflicting over their ideas of disk geometry. You will
`have to reinstall FreeBSD, but obeying the instructions given above will almost always get you going.
`
`5 of 8
`
`Page 5 of 8
`
`
`
`https://web.archive.org/web/20020404064240/http://www.freebsd.org:80/doc/en_US.ISO8859-1/books/faq/install.html
`
`JUN
`
`3.23. Why can I not get past the boot manager's
`t?
`This is another symptom of the problem described in the preceding question. Your BIOS geometry and FreeBSD geometry
`200
`settings do not agree! If your controller or BIOS supports cylinder translation (often marked as ``>1GB drive support''), try
`toggling its setting and reinstalling FreeBSD.
`3.24. Do I need to install the complete sources?
`In general, no. However, we would strongly recommend that you install, at a minimum, the base source kit, which includes
`several of the files mentioned here, and the sys (kernel) source kit, which includes sources for the kernel. There is nothing
`in the system which requires the presence of the sources to operate, however, except for the kernel-configuration program
`config(8). With the exception of the kernel sources, our build structure is set up so that you can read-only mount the sources
`from elsewhere via NFS and still be able to make new binaries. (Because of the kernel-source restriction, we recommend
`that you not mount this on /usr/src directly, but rather in some other location with appropriate symbolic links to duplicate
`the top-level structure of the source tree.)
`Having the sources on-line and knowing how to build a system with them will make it much easier for you to upgrade to
`future releases of FreeBSD.
`To actually select a subset of the sources, use the Custom menu item when you are in the Distributions menu of the system
`installation tool.
`3.25. Do I need to build a kernel?
`Building a new kernel was originally pretty much a required step in a FreeBSD installation, but more recent releases have
`benefited from the introduction of a much friendlier kernel configuration tool. When at the FreeBSD boot prompt (boot:),
`use the -c flag and you will be dropped into a visual configuration screen which allows you to configure the kernel's settings
`for most common ISA cards.
`It is still recommended that you eventually build a new kernel containing just the drivers that you need, just to save a bit of
`RAM, but it is no longer a strict requirement for most systems.
`3.26. Should I use DES passwords, or MD5, and how do I specify which form my users receive?
`The default password format on FreeBSD is to use MD5-based passwords. These are believed to be more secure than the
`traditional Unix password format, which used a scheme based on the DES algorithm. DES passwords are still available if
`you need to share your password file with legacy operating systems which still use the less secure password format (they are
`available if you choose to install the ``crypto'' distribution in sysinstall, or by installing the crypto sources if building from
`source). Which password format to use for new passwords is controlled by the ``passwd_format'' login capability in
`/etc/login.conf, which takes values of either ``des'' (if available) or ``md5''. See the login.conf(5) manual page for more
`information about login capabilities.
`3.27. Why does the boot floppy start, but hang at the Probing Devices... screen?
`If you have a IDE Zip or Jaz drive installed, remove it and try again. The boot floppy can get confused by the drives. After
`the system is installed you can reconnect the drive. Hopefully this will be fixed in a later release.
`3.28. Why do I get a ``panic: can't mount root'' error when rebooting the system after installation?
`This error comes from confusion between the boot block's and the kernel's understanding of the disk devices. The error
`usually manifests on two-disk IDE systems, with the hard disks arranged as the master or single device on separate IDE
`controllers, with FreeBSD installed on the secondary IDE controller. The boot blocks think the system is installed on wd1
`(the second BIOS disk) while the kernel assigns the first disk on the secondary controller device wd2. After the device
`probing, the kernel tries to mount what the boot blocks think is the boot disk, wd1, while it is really wd2, and fails.
`To fix the problem, do one of the following:
`For FreeBSD 3.3 and later, reboot the system and hit Enter at the Booting kernel in 10 seconds; hit
`1.
`[Enter] to interrupt prompt. This will drop you into the boot loader.
`Then type set root_disk_unit="disk_number" . disk_number will be 0 if FreeBSD is installed on the master
`drive on the first IDE controller, 1 if it is installed on the slave on the first IDE controller, 2 if it is installed on
`the master of the second IDE controller, and 3 if it is installed on the slave of the second IDE controller.
`Then type boot, and your system should boot correctly.
`To make this change permanent (ie so you do not have to do this every time you reboot or turn on your
`FreeBSD machine), put the line root_disk_unit="disk_number" in /boot/loader.conf.local .
`If using FreeBSD 3.2 or earlier, at the Boot: prompt, enter 1:wd(2,a)kernel and press Enter. If the system
`starts, then run the command echo "1:wd(2,a)kernel" > /boot.config to make it the default boot string.
`
`2.
`
`6 of 8
`
`Page 6 of 8
`
`
`
`https://web.archive.org/web/20020404064240/http://www.freebsd.org:80/doc/en_US.ISO8859-1/books/faq/install.html
`
`JUN
`
`200
`
`3.
`4.
`
`Move the FreeBSD disk onto the primary IDE controller, so the hard disks are consecutive.
`Rebuild your kernel,
`dif
`th
`d
`fi
`ti
`li
`t
`d
` controller wdc0 at isa? port "IO_WD1" bio irq 14 vector wdintr
` disk wd0 at wdc0 drive 0
` # disk wd1 at wdc0 drive 1 # comment out this line
`
` controller wdc1 at isa? port "IO_WD2" bio irq 15 vector wdintr
` disk wd1 at wdc1 drive 0 # change from wd2 to wd1
` disk wd2 at wdc1 drive 1 # change from wd3 to wd2
`Install the new kernel. If you moved your disks and wish to restore the previous configuration, replace the disks
`in the desired configuration and reboot. Your system should boot successfully.
`3.29. What are the limits for memory?
`For memory, the limit is 4 gigabytes. This configuration has been tested, see wcarchive's configuration for more details. If
`you plan to install this much memory into a machine, you need to be careful. You will probably want to use ECC memory
`and to reduce capacitive loading use 9 chip memory modules versus 18 chip memory modules.
`3.30. What are the limits for ffs filesystems?
`For ffs filesystems, the maximum theoretical limit is 8 terabytes (2G blocks), or 16TB for the default block size of 8K. In
`practice, there is a soft limit of 1 terabyte, but with modifications filesystems with 4 terabytes are possible (and exist).
`The maximum size of a single ffs file is approximately 1G blocks (4TB) if the block size is 4K.
`Table 3-1. Maximum file sizes
`
`should work
`fs block size 2.2.7-stable 3.0-current works
`>4T
`4K
`4T-1
`4T-1
`4T-1
`8K
`>32G
`8T-1
`>32G 32T-1
`16K
`>128G
`16T-1
`>128G 32T-1
`32K
`>512G
`32T-1
`>512G 64T-1
`64K
`>2048G
`64T-1
`>2048G 128T-1
`
`When the fs block size is 4K, triple indirect blocks work and everything should be limited by the maximum fs block number
`that can be represented using triple indirect blocks (approx. 1K^3 + 1K^2 + 1K), but everything is limited by a (wrong) limit
`of 1G-1 on fs block numbers. The limit on fs block numbers should be 2G-1. There are some bugs for fs block numbers near
`2G-1, but such block numbers are unreachable when the fs block size is 4K.
`For block sizes of 8K and larger, everything should be limited by the 2G-1 limit on fs block numbers, but is actually limited
`by the 1G-1 limit on fs block numbers, except under -STABLE triple indirect blocks are unreachable, so the limit is the
`maximum fs block number that can be represented using double indirect blocks (approx. (blocksize/4)^2 + (blocksize/4)),
`and under -CURRENT exceeding this limit may cause problems. Using the correct limit of 2G-1 blocks does cause
`problems.
`3.31. Why do I get an error message, ``archsw.readin.failed'' after compiling and booting a new kernel?
`You can boot by specifying the kernel directly at the second stage, pressing any key when the | shows up before loader is
`started. More specifically, you have upgraded the source for your kernel, and installed a new kernel builtin from them
`without making world. This is not supported. Make world.
`3.32. How do I upgrade from 3.X -> 4.X?
`We strongly recommend that you use binary snapshots to do this. 4-STABLE snapshots are available at
`ftp://releng4.FreeBSD.org/.
`Because of the many changes between 3.X and 4-STABLE, a direct upgrade from source will probably fail. A source
`upgrade can be done, but only in stages. First, upgrade to the latest 3-STABLE (RELENG_3). Then upgrade to 4.1.1-
`RELEASE (RELENG_4_1_1_RELEASE). Finally, upgrade to 4-STABLE (RELENG_4).
`If you wish to upgrade using source, please see the FreeBSD Handbook for more information.
`Caution: Upgrading via source is never recommended for new users, and upgrading from 3.X to 4.X is even
`less so; make sure you have read the instructions carefully before attempting to upgrade via source.
`3.33. What are these ``security profiles''?
`A ``security profile'' is a set of configuration options that attempts to achieve the desired ratio of security to convenience by
`enabling and disabling certain programs and other settings. For full details, see the Security Profile section of the
`
`7 of 8
`
`Page 7 of 8
`
`
`
`https://web.archive.org/web/20020404064240/http://www.freebsd.org:80/doc/en_US.ISO8859-1/books/faq/install.html
`
`Handbook's post-install chapter
`
`Notes
`[1]
`
`In an e-mail from Keith Frechette <kfrechet@us.ibm.com>.
`
`JUN
`
`200
`
`Prev
`Documentation and Support
`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>.
`
`Home
`
`Next
`Hardware compatibility
`
`8 of 8
`
`Page 8 of 8
`
`