Do you want to do a binary upgrade of your running FreeBSD installation? Use freebsd-update(8).

To install updates and patches for the running branch use

# freebsd-update fetch install

To upgrade to a newer release use

# freebsd-update upgrade -r ${name_of_release}

-- Lars Engels

Sometimes a single slow HDD can cripple the performance of your entire system. You can spot one like this:

# gstat -I5s | sort -rn -k9 | head

-- Alan Somers

%

To determine whether a file is a text file, executable, or some other type

of file, use

file filename

-- Dru

Want to know how many words, lines, or bytes are contained in a file? Type

"wc filename".

-- Dru

You can use "pkg info" to see a list of packages you have installed.

"man security" gives very good advice on how to tune the security of your

FreeBSD system.

nc(1) (or netcat) is useful not only for redirecting input/output to

TCP or UDP connections, but also for proxying them with inetd(8).

The "zfs list" command can be filtered in multiple ways. To display just

the dataset name, use the -o parameter:

zfs list -o name mypool/usr

More columns and their order can be defined by separating them with commas:

zfs list -o mountpoint,name,avail

-- Benedict Reuschling

You can make a log of your terminal session with script(1).

A user "sender" needs the following permissions set to send a ZFS dataset:

# zfs allow -u sender send,snapshot txpool

On the receiving side, the user "receiver" requires these permissions:

# zfs allow -u receiver compression,mountpoint,mount,create,receive rxpool

-- Benedict Reuschling

If other operating systems have damaged your Master Boot Record, you can

reinstall it with gpart(8). See

"man gpart" for details.

To find out the hostname associated with an IP address, use

drill -x IP_address

-- Dru

Forget when Easter is? Try "ncal -e". If you need the date for Orthodox

Easter, use "ncal -o" instead.

-- Dru

ZFS keeps a history of commands run against a specific pool using the

history subcommand to zpool:

zpool history

More details are available using the -i and -l parameters. Note that ZFS

will not keep the complete pool history forever and will remove older

events in favor of never ones.

-- Benedict Reuschling

You can limit the depth of the displayed datasets in the "zfs list" output

using the -d parameter. To display only the first level of datasets below

mypool/usr and not the ones deeper than those, run this command:

zfs list -d 1 mypool/usr

-- Benedict Reuschling

Simple tcsh prompt: set prompt = '%# '

To display the compression ratio for the ZFS dataset /var/log on the pool

mypool, run the following command:

zfs get refcompressratio mypool/var/log

The refcompressratio will only display the compression ratio for that specific

dataset, not the descendant datasets. To include the child datasets, the

command looks like this:

zfs get compressratio mypool/var

-- Benedict Reuschling

To see all of the directories on your FreeBSD system, type

find / -type d | less

All the files?

find / -type f | less

To see the IP addresses currently set on your active interfaces, type

"ifconfig -u".

-- Dru

When you want your users to be able to reboot or shutdown FreeBSD, add them

to the group "operator" and they are allowed to use shutdown(8) and poweroff(8).

-- Lars Engels