Setting up disks with FreeBSD.
The New Standard: GPT
GPT is the newer and more versatile partition method. Use it unless
compatibility with the old standard MBR is required.
The disk device being set up here is da0.
Create a GPT partition scheme on /dev/da0. /dev/ is implied:
# gpart create -s gpt da0
da0 created
Create a boot partition to hold the loader, size of 512K. Give it
a GPT label of gpboot, which will show up in /dev/gpt when the
device is discovered:
# gpart add -t freebsd-boot -l gpboot -b 40 -s 512K da0
da0p1 added
Install the GPT bootcode into the boot partition:
# gpart bootcode -b /boot/pmbr -p /boot/gptboot -i 1 da0
bootcode written to da0
Create a partition for /. It should start at the 1M boundary for
proper sector alignment on 4K sector drives or SSDs. This is compatible
with GPT drive layout for many other systems. Give it a GPT label of
gprootfs.
# gpart add -t freebsd-ufs -l gprootfs -b 1M -s 2G da0
da0p2 added
Create partitions for swap, /var, /tmp, /usr. Leaving the -s
size option off the last uses the rest of the disk. As long as these
are even sizes in M or G, the alignment will remain correct. Add -a
1M to force alignment of both starting position and size to one
megabyte.
# gpart add -t freebsd-swap -l gpswap -s 512M da0
da0p3 added
# gpart add -t freebsd-ufs -l gpvarfs -s 1G da0
da0p4 added
# gpart add -t freebsd-ufs -l gptmpfs -s 256M da0
da0p5 added
# gpart add -t freebsd-ufs -l gpusrfs -a 1M da0
da0p6 added
# gpart show -l da0
=> 34 19640813 da0 GPT (9.4G)
34 6 - free - (3.0k)
40 1024 1 gpboot (512k)
1064 984 - free - (492k)
2048 4194304 2 gprootfs (2.0G)
4196352 1048576 3 gpswap (512M)
5244928 2097152 4 gpvarfs (1.0G)
7342080 524288 5 gptmpfs (256M)
7866368 11773952 6 gpusrfs (5.6G)
|
If there’s a need or desire to redo this partition layout,
gpart(8)
won’t destroy the "geom" until all of the partitions in it have been
deleted:
Later versions of gpart(8) have a -F (force) option for destroy that
makes things quicker but sort of blunt and stabby at the same time:
|
Format the new filesystems, enabling soft updates for performance.
Filesystem labels can be added here, but probably should not be
the same as the GPT labels already assigned.
# newfs -U /dev/gpt/gprootfs
# newfs -U /dev/gpt/gpvarfs
# newfs -U /dev/gpt/gptmpfs
# newfs -U /dev/gpt/gpusrfs
See
http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/disks.html#SAFE-SOFTUPDATES
for more information on using soft updates on the root filesystem.
Restore data. Labels are used in the
mount command here because
they’re easier to identify, but device names like /dev/da0p2 will
work.# mount /dev/gpt/gprootfs /mnt
# (cd /mnt && gzcat root.dump.gz | restore -ruf -)
# umount /mnt
Repeat for /var, /tmp, /usr.
Modify /etc/fstab:
# Device Mountpoint FStype Options Dump Pass#
/dev/gpt/gpswap none swap sw 0 0
/dev/gpt/gprootfs / ufs rw 1 1
/dev/gpt/gptmpfs /tmp ufs rw 2 2
/dev/gpt/gpusrfs /usr ufs rw 2 2
/dev/gpt/gpvarfs /var ufs rw 2 2
Done!
The Old Standard: MBR
Usually the GPT setup above is the better choice. This older method
creates an MBR partition table, which can be useful for backwards
compatibility.
Again, we’re setting up da0.
|
If remnants of a GPT partitioning scheme are still present on the disk,
it will be seen instead of the MBR. Destroying that old partitioning
scheme before creating the new MBR is important.
Older versions of gpart(8) did not have -F to easily remove old
partition schemes without deleting all partitions first. An alternate
way to remove GPT tables is using dd(1) to overwrite the GPT primary
table at the start of the disk:
Removing the secondary or backup GPT table at the end of the disk
requires a little calculation. Use diskinfo(8) to get the number of
blocks, subtract the 34-block length of the standard table, and write
from there to the end of the disk. In this example, the disk has
60030432 blocks. Subtracting 34 from that gives 60030398 as the starting
location, and dd(1) will write from there to the end of the disk.
|
Create the MBR partitioning scheme:
# gpart create -s mbr da0
Make it bootable by installing bootcode.
# gpart bootcode -b /boot/mbr da0
Create an MBR partition. FreeBSD calls these "slices". Set it active
so the system will boot from it.
# gpart add -t freebsd da0
# gpart set -a active -i 1 da0
Inside the FreeBSD slice, create a bsdlabel partitioning scheme.
Bootcode is needed here also.
# gpart create -s bsd da0s1
# gpart bootcode -b /boot/boot da0s1
Create the FreeBSD "partitions" inside the slice.
# gpart add -t freebsd-ufs -a 4k -s 2g da0s1
# gpart add -t freebsd-swap -a 4k -s 512m da0s1
# gpart add -t freebsd-ufs -a 4k -s 1g da0s1
# gpart add -t freebsd-ufs -a 4k -s 256m da0s1
# gpart add -t freebsd-ufs -a 4k da0s1
Format and label the filesystems before they are mounted, enabling soft
updates for better performance:
# glabel label swap /dev/da0s1b
# newfs -L rootfs -U /dev/da0s1a
# newfs -L varfs -U /dev/da0s1d
# newfs -L tmpfs -U /dev/da0s1e
# newfs -L usrfs -U /dev/da0s1f
See
http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/disks.html#SAFE-SOFTUPDATES
for more information on using soft updates on the root filesystem.
Restore data to the new filesystems:
# mount /dev/da0s1a /mnt
# gzcat root.dump.gz | (cd /mnt && restore -rf -)
# umount /mnt
Repeat for /var, /tmp, /usr.
Modify /etc/fstab:
# Device Mountpoint FStype Options Dump Pass#
/dev/label/swap none swap sw 0 0
/dev/ufs/rootfs / ufs rw 1 1
/dev/ufs/tmpfs /tmp ufs rw 2 2
/dev/ufs/usrfs /usr ufs rw 2 2
/dev/ufs/varfs /var ufs rw 2 2
Done!
The New Standard: GPT
GPT is the newer and more versatile partition method. Use it unless
compatibility with the old standard MBR is required.
The disk device being set up here is da0.
Create a GPT partition scheme on /dev/da0. /dev/ is implied:
# gpart create -s gpt da0
da0 created
Create a boot partition to hold the loader, size of 512K. Give it
a GPT label of gpboot, which will show up in /dev/gpt when the
device is discovered:
# gpart add -t freebsd-boot -l gpboot -b 40 -s 512K da0
da0p1 added
Install the GPT bootcode into the boot partition:
# gpart bootcode -b /boot/pmbr -p /boot/gptboot -i 1 da0
bootcode written to da0
Create a partition for /. It should start at the 1M boundary for
proper sector alignment on 4K sector drives or SSDs. This is compatible
with GPT drive layout for many other systems. Give it a GPT label of
gprootfs.
# gpart add -t freebsd-ufs -l gprootfs -b 1M -s 2G da0
da0p2 added
Create partitions for swap, /var, /tmp, /usr. Leaving the -s
size option off the last uses the rest of the disk. As long as these
are even sizes in M or G, the alignment will remain correct. Add -a
1M to force alignment of both starting position and size to one
megabyte.
# gpart add -t freebsd-swap -l gpswap -s 512M da0
da0p3 added
# gpart add -t freebsd-ufs -l gpvarfs -s 1G da0
da0p4 added
# gpart add -t freebsd-ufs -l gptmpfs -s 256M da0
da0p5 added
# gpart add -t freebsd-ufs -l gpusrfs -a 1M da0
da0p6 added
# gpart show -l da0
=> 34 19640813 da0 GPT (9.4G)
34 6 - free - (3.0k)
40 1024 1 gpboot (512k)
1064 984 - free - (492k)
2048 4194304 2 gprootfs (2.0G)
4196352 1048576 3 gpswap (512M)
5244928 2097152 4 gpvarfs (1.0G)
7342080 524288 5 gptmpfs (256M)
7866368 11773952 6 gpusrfs (5.6G)|
|
If there’s a need or desire to redo this partition layout,
gpart(8)
won’t destroy the "geom" until all of the partitions in it have been
deleted:
Later versions of gpart(8) have a -F (force) option for destroy that
makes things quicker but sort of blunt and stabby at the same time:
|
Format the new filesystems, enabling soft updates for performance.
Filesystem labels can be added here, but probably should not be
the same as the GPT labels already assigned.
# newfs -U /dev/gpt/gprootfs
# newfs -U /dev/gpt/gpvarfs
# newfs -U /dev/gpt/gptmpfs
# newfs -U /dev/gpt/gpusrfs
See
http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/disks.html#SAFE-SOFTUPDATES
for more information on using soft updates on the root filesystem.
Restore data. Labels are used in the
mount command here because
they’re easier to identify, but device names like /dev/da0p2 will
work.# mount /dev/gpt/gprootfs /mnt
# (cd /mnt && gzcat root.dump.gz | restore -ruf -)
# umount /mnt
Repeat for /var, /tmp, /usr.
Modify /etc/fstab:
# Device Mountpoint FStype Options Dump Pass#
/dev/gpt/gpswap none swap sw 0 0
/dev/gpt/gprootfs / ufs rw 1 1
/dev/gpt/gptmpfs /tmp ufs rw 2 2
/dev/gpt/gpusrfs /usr ufs rw 2 2
/dev/gpt/gpvarfs /var ufs rw 2 2
Done!
The Old Standard: MBR
Usually the GPT setup above is the better choice. This older method
creates an MBR partition table, which can be useful for backwards
compatibility.
Again, we’re setting up da0.
|
|
If remnants of a GPT partitioning scheme are still present on the disk,
it will be seen instead of the MBR. Destroying that old partitioning
scheme before creating the new MBR is important.
Older versions of gpart(8) did not have -F to easily remove old
partition schemes without deleting all partitions first. An alternate
way to remove GPT tables is using dd(1) to overwrite the GPT primary
table at the start of the disk:
Removing the secondary or backup GPT table at the end of the disk
requires a little calculation. Use diskinfo(8) to get the number of
blocks, subtract the 34-block length of the standard table, and write
from there to the end of the disk. In this example, the disk has
60030432 blocks. Subtracting 34 from that gives 60030398 as the starting
location, and dd(1) will write from there to the end of the disk.
|
Create the MBR partitioning scheme:
# gpart create -s mbr da0
Make it bootable by installing bootcode.
# gpart bootcode -b /boot/mbr da0
Create an MBR partition. FreeBSD calls these "slices". Set it active
so the system will boot from it.
# gpart add -t freebsd da0
# gpart set -a active -i 1 da0
Inside the FreeBSD slice, create a bsdlabel partitioning scheme.
Bootcode is needed here also.
# gpart create -s bsd da0s1
# gpart bootcode -b /boot/boot da0s1
Create the FreeBSD "partitions" inside the slice.
# gpart add -t freebsd-ufs -a 4k -s 2g da0s1
# gpart add -t freebsd-swap -a 4k -s 512m da0s1
# gpart add -t freebsd-ufs -a 4k -s 1g da0s1
# gpart add -t freebsd-ufs -a 4k -s 256m da0s1
# gpart add -t freebsd-ufs -a 4k da0s1
Format and label the filesystems before they are mounted, enabling soft
updates for better performance:
# glabel label swap /dev/da0s1b
# newfs -L rootfs -U /dev/da0s1a
# newfs -L varfs -U /dev/da0s1d
# newfs -L tmpfs -U /dev/da0s1e
# newfs -L usrfs -U /dev/da0s1f
See
http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/disks.html#SAFE-SOFTUPDATES
for more information on using soft updates on the root filesystem.
Restore data to the new filesystems:
# mount /dev/da0s1a /mnt
# gzcat root.dump.gz | (cd /mnt && restore -rf -)
# umount /mnt
Repeat for /var, /tmp, /usr.
Modify /etc/fstab:
# Device Mountpoint FStype Options Dump Pass#
/dev/label/swap none swap sw 0 0
/dev/ufs/rootfs / ufs rw 1 1
/dev/ufs/tmpfs /tmp ufs rw 2 2
/dev/ufs/usrfs /usr ufs rw 2 2
/dev/ufs/varfs /var ufs rw 2 2
Done!
