CIRCLE WITH A DOT

"man security" gives very good advice on how to tune the security of yourFreeBSD system.

To make the "zfs list" output more script-friendly, you can suppress theoutput of the headers for each column by passing the -H parameter:zfs list -HAnother helpful option for script writers is -p, which displays the numbersin non-rounded, exact values:zfs list -p -- Benedict Reuschling <bcr@FreeBSD.org>

To set a custom ZFS property on the mypool pool, you need to provide itusing the "key1:key2=value" syntax, where the colon (:) is used as theseparator and identifier from the built-in ZFS properties:# zfs set warranty:expires=2038-01-19 mypoolThe custom property is applied to all datasets and can be queried like anybuilt-in properties using zfs get:zfs get warranty:expires mypoolTo reset the value of a custom property, use the inherit subcommand:# zfs inherit warranty:expires mypoolRemoving a custom property from a pool is done using the -r flag to the"zfs inherit" command:# zfs inherit -r warranty:expires mypool -- Benedict Reuschling <bcr@FreeBSD.org>

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The output of "zfs list" can be sorted by a specific column using -s. Tosort the datasets by the "used" column in ascending order, run this command:zfs list -s usedTo sort in descending order instead, use -S:zfs list -S used -- Benedict Reuschling <bcr@FreeBSD.org>

If you want to recursively copy a directory preserving file and directoryattributes use"cp -a source target" -- Lars Engels <lme@FreeBSD.org>

You can use /etc/make.conf to control the options used to compile softwareon this system. Example entries are in/usr/share/examples/etc/make.conf and in make.conf(5).For options that are set for building FreeBSD's kernel and its world, seesrc.conf(5).

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 thefollowing command:# zfs hold milestone_hold mypool/projects@my_milestoneThe "zfs holds" command will list all current snapshots that are protectedthis way (-r for a recursive list):# zfs holds -r mypoolThe TIMESTAMP column in the output of the above command is from when thehold was created, not the snapshot it holds. The "zfs destroy" command willecho 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>

You can automatically download and install binary packages by doing pkg install <package>This will also automatically install the packages that are dependenciesfor the package you install (ie, the packages it needs in order to work.)

You can disable tcsh's terminal beep if you `set nobeep'.

ZFS keeps a history of commands run against a specific pool using thehistory subcommand to zpool:zpool historyMore details are available using the -i and -l parameters. Note that ZFSwill not keep the complete pool history forever and will remove olderevents in favor of never ones. -- Benedict Reuschling <bcr@FreeBSD.org>

Forget what directory you are in? Type "pwd". -- Dru <genesis@istar.ca>

When using ZFS as the file system the "df" command is reporting the pool sizeand not file system sizes. It also does not know about descendent ZFSdatasets, snapshots, quotas, and reservations with their individual space usage. Use the built-in "zfs list" command to get a better overview of space usage:zfs list -o space -- Benedict Reuschling <bcr@FreeBSD.org>

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 statsevery 5 seconds run the following command (cancel with CTRL+C):zpool iostat 5To view individual disk activities, specify the -v parameter:zpool iostat -vOf course, both can be combined. For more options, see zpool(8). -- Benedict Reuschling <bcr@FreeBSD.org>

You can adjust the volume of various parts of the sound system in yourcomputer by typing 'mixer <type> <volume>'. To get a list of what you canadjust, just type 'mixer'.

Forget when Easter is? Try "ncal -e". If you need the date for OrthodoxEaster, use "ncal -o" instead. -- Dru <genesis@istar.ca>

Can't delete /usr/obj? Enter "chflags -R noschg /usr/obj" to remove thesystem immutable flag for all files in /usr/obj. -- Lars Engels <lme@FreeBSD.org>

Are you looking for a package? Search for it with"pkg search part_of_package_name" -- Lars Engels <lme@FreeBSD.org>

When you want your users to be able to reboot or shutdown FreeBSD, add themto the group "operator" and they are allowed to use shutdown(8) and poweroff(8). -- Lars Engels <lme@FreeBSD.org>

nc(1) (or netcat) is useful not only for redirecting input/output toTCP or UDP connections, but also for proxying them with inetd(8).