Want to go the directory you were just in?
Type "cd -"

If you want df(1) and other commands to display disk sizes in
kilobytes instead of 512-byte blocks, set BLOCKSIZE in your
environment to 'K'. You can also use 'M' for Megabytes or 'G' for
Gigabytes. If you want df(1) to automatically select the best size
then use 'df -h'.

To see how long it takes a command to run, type the word "time" before the
command name.
-- Dru <genesis@istar.ca>

Need to find the location of a program? Use "locate program_name".
-- Dru <genesis@istar.ca>

Time to change your password? Type "passwd" and follow the prompts.
-- Dru <genesis@istar.ca>

You can permanently set environment variables for your shell by putting them
in a startup file for the shell. The name of the startup file varies
depending on the shell - csh and tcsh uses .login, bash, sh, ksh and zsh use
.profile. When using bash, sh, ksh or zsh, don't forget to export the
variable.

ZFS can display I/O statistics for a given pool using the iostat subcommand.
By default, it will display one line of current activity. To display stats
every 5 seconds run the following command (cancel with CTRL+C):

zpool iostat 5

To view individual disk activities, specify the -v parameter:

zpool iostat -v

Of course, both can be combined. For more options, see zpool(8).
-- Benedict Reuschling <bcr@FreeBSD.org>

In order to search for a string in some files, use 'grep' like this:

grep "string" filename1 [filename2 filename3 ...]

This will print out the lines in the files that contain the string. grep can
also do a lot more advanced searches - type 'man grep' for details.

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

drill -x IP_address
-- Dru <genesis@istar.ca>

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 <bcr@FreeBSD.org>

To read a compressed file without having to first uncompress it, use
"zcat" or "zless" to view it. There is also "bzcat", "bzless", "xzcat"
and "xzless".
-- Dru <genesis@istar.ca>

After you compiled and installed a new version of FreeBSD, use etcupdate(8) to merge
configuration updates.
Run "etcupdate extract" once when your sources match your running system, then run
"etcupdate" after every upgrade and "etcupdate resolve" to resolve any conflicts.

-- Lars Engels <lme@FreeBSD.org>

To change an environment variable in tcsh you use: setenv NAME "value"
where NAME is the name of the variable and "value" its new value.

If you do not want to get beeps in X11 (X Windows), you can turn them off with

xset b off

If you want to play CDs with FreeBSD, a utility for this is already included.
Type 'cdcontrol' then 'help' to learn more. (You may need to set the CDROM
environment variable in order to make cdcontrol want to start.)

You can prevent the removal of a ZFS snapshot by using the hold subcommand.
For example, to prevent the snapshot called milestone from deletion, run the
following command:

# zfs hold milestone_hold mypool/projects@my_milestone

The "zfs holds" command will list all current snapshots that are protected
this way (-r for a recursive list):

# zfs holds -r mypool

The TIMESTAMP column in the output of the above command is from when the
hold was created, not the snapshot it holds. The "zfs destroy" command will
echo a "dataset is busy" message on the console when it encounters a hold.
Use "zfs release" to release the hold on the snapshot:

# zfs release milestone_hold mypool/projects@my_milestone

-- Benedict Reuschling <bcr@FreeBSD.org>

Before deleting a dataset or snapshot, perform a dry run using the -n
parameter. This is to make sure you really want to delete just that
dataset/snapshot and not any dependent ones. ZFS will display the resulting
action when -n is combined with the -v option without actually performing
it:

zfs destroy -nrv mypool@mysnap

Once you are sure this is exactly what you intend to do, remove the -n
parameter to execute the destroy operation.
-- Benedict Reuschling <bcr@FreeBSD.org>

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

To search for files that match a particular name, use find(1); for example

find / -name "*GENERIC*" -ls

will search '/', and all subdirectories, for files with 'GENERIC' in the name.
-- Stephen Hilton <nospam@hiltonbsd.com>

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

find / -type d | less

All the files?

find / -type f | less