Editing FreeBSD (section)

== Technical Notes ==



=== Disk image via dd ===

dd bs=512 if=/dev/rXX# of=/some_dir/foo.dmg conv=noerror,sync

=== tar over netcat ===

* nc -v -v -w 40 -l -p 8888 > foo.tar
* tar cjvf * | nc remotehost 8888

=== Updating root DNS ===

dig @a.root-servers.net . ns > /etc/namedb/named.root

=== Qmail log Timestamps ===

Can be converted to human readable using the tai64nlocal command.

=== Name Services ===

==== Retrieving Database Entries ====

As of FreeBSD 7 the ''getent'' utility can be used to retrieve entries from the various administrative databases.

==== Name Service Caching Daemon ====

The nscd daemon added in FreeBSD 7 improves performance of nsswitch type lookups (users, groups, etc) but can cause some surprising results with new users not being found in the system. The cache can be cleared for all users by running:

<pre>%nscd -I cachename</pre>

=== Using IDE CD Burners ===

Place the following in /boot/loader.conf for IDE CDRW support:

 atapicam_load="YES"
 hw.ata.atapi_dma=1

=== Using Memory Disks ===

FreeBSD >= 5.x have a memory disk utility that can be utilized to mount file system images.

To setup a memory disk

 mdconfig -a -t vnode -o readonly -f /path/to/image.iso -u 1
 mount -t cd9660 /dev/md1 /mnt/cdrom

To reverse the process:

 mount -u /mnt/cdrom
 mdconfig -d -u 1

=== Displaying Dates in 12 Hour Format ===

Add the following to .cshrc or /etc/csh.cshrc (system wide):

 alias date date +\"%a %b %e %r %Z %Y\"

=== View Daylight Savings Dates ===

 zdump -v /etc/localtime | grep ''2008''

=== List BIND Domains ===

 grep ^zone < /etc/namedb/named.conf | sed -e 's/zone "\(.*\)".*/\1/g' | sort

=== Find Hosts in a Subnet ===

 nmap -sP 172.31.0.128/26

=== Build Port with Debugging Symbols ===

 make WITH_DEBUG=yes

=== Setup LDAP Authentication ===

Install required ports:

 sudo portinstall nss_ldap
 sudo portinstall pam_ldap

Setup ''nss_ldap.conf''

<pre>
host 172.31.0.1
base dc=incoherency,dc=net
uri ldap://172.31.0.1:389/
ssl start_tls

binddn uid=nss,ou=dsa,dc=incoherency,dc=net
bindpw ********
bind_policy soft

nss_initgroups_ignoreusers root,ldap

timelimit 5
nss_reconnect_tries 2

port 389
nss_base_passwd dc=incoherency,dc=net?subtree
nss_base_group  ou=groups,dc=incoherency,dc=net?one
pam_password SSHA
</pre>

Link ldap.conf to nss_ldap.conf

 ln -s nss_ldap.conf ldap.conf

Add the following to /etc/pam.d/ for each relevant service

 auth		sufficient	/usr/local/lib/pam_ldap.so	no_warn try_first_pass

Edit /etc/nsswitch.conf:

 passwd: files ldap
 group: files ldap

=== Fix for freebsd-update ===

 %sudo freebsd-update upgrade -r 7.1-RC1
 Looking up update.FreeBSD.org mirrors... 1 mirrors found.
 Fetching metadata signature for 7.1-PRERELEASE from update1.FreeBSD.org... failed.
 No mirrors remaining, giving up.
 %

 %setenv UNAME_r 7.1-BETA2
 %freebsd-update upgrade -r 7.1-RC1
 Looking up update.FreeBSD.org mirrors... 1 mirrors found.
 Fetching metadata signature for 7.1-BETA2 from update1.FreeBSD.org... done.
 Fetching metadata index... done.
 Inspecting system... done.

 ...

=== Install a standard MBR ===

Useful if you inadvertently install the FreeBSD boot manager or if you need to borrow a standard MBR for use on an OS that doesn't have one yet *cough* Haiku

 fdisk −B −b /boot/mbr ad0

=== Avoid config menus on port builds ===

 make config-recursive install

=== Mount ISO Image ===

 mdconfig -a -t vnode -f <ISO filename> -u 0
 mount -t cd9660 /dev/md0 <mount destination>

=== VirtualBox ===

* [http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/virtualization-host.html FreeBSD Handbook]
* [http://www.virtualbox.org/manual/ch08.html#vboxmanage VBoxManage]

=== Connect to TLS server ===
 openssl s_client -starttls smtp -connect smtp.gmail.com:587