Linux Notes

These Linux Notes are based on Redhat 7. If your using them, some knowlege of Linux is assumed, these are here mainly so I don't have to remember them.

Some Notes on installing Bluetooth on a Redhat 7.3 Linux Box
Controlling a SliMp3 Player using Bluetooth

Command	What it Does
make menuconfig	Easy(ier) kernel editor
/usr/sbin/ntsysv	To configure what services run at bootup
find . -name <file> -print	Find a file, and show its location
find . -name "*" -exec grep -l "<some text>" {} ";"	Find some text within an unknown file and display the name of that file.
tar czvf <destination> <source>	To TAR and compress a directory
gunzip -c <filename>.gz \| less	To view the text of a gzipped file
rm -rf /<directory>/	DELTREE equivalent (use with caution)
mount -t iso9660 /dev/cdrom /mnt	To mount a CD-ROM disc
ps aex \| less	Show all processes
/sbin/pump -i eth0 --status	To check the IP status of an NIC (in this case eth0).
ifconfig	Tells you your IP and MAC address(es).
mkisofs -r -o name_of.iso /directory_of_files	Will create an ISO image with the contents of the directory in it.
dd if=/dev/cdrom of=/somewhere/name_of.iso	Will copy a CD to an ISO image.
mount /dir/name_of.iso /mnt/iso/ -t iso9660 -o loop	Mounts an ISO file
uname -a	Display the kernel version

Installing a new Hard Drive

The example shown installs a new volume called home2. Use the volume name so that it can be mounted automatically in /etc/fstab and if the hard drives are changed at a later date it'll still mount correctly.

Note: The <device> name changes once you have finished setting up the partitions with cfdisk, eg. /dev/hdb becomes /dev/hdb1 /dev/hdb2 /dev/hdb3 etc… depending of the number of partitions you have created.

Command	Example	Notes
cfdisk <device>	cfdisk /dev/hdb	A version of fdisk
mkfs.ext2 <device>	mkfs.ext2 /dev/hdb1	Format the drive
e2label <device> <vol name>	e2label /dev/hdb1 /home2	Set the Volume Name
mkdir <vol name>	mkdir /home2	Make the volume directory
mount -t ext2 <device> <vol name>	mount -t ext2 /dev/hdb1 /home2	Mount the drive
pico /etc/fstab		Edit fstab as appropriate

If you want to replace your home volume with a bigger hard drive follow the steps above (except mkdir), and use e2label to rename the existing /home to /home2 then name the new hard disk /home when you re-boot the new hard drive will be mounted instead. Don't forget to copy everything across.

RJ-45 (Cat 5) Connections

Pin one is on the left, looking onto the gold connectors. With the catch on the bottom

Ordinary Cable			Crossover cable
both ends are the same			connector one		connector two
1.	White Orange	Data TX+	1.	White Orange	1.	White Green
2.	Orange	Data TX-	2.	Orange	2.	Green
3.	White Green	Data RX+	3.	White Green	3.	White Orange
4.	Blue		4.	Blue	4.	Blue
5.	White Blue		5.	White Blue	5.	White Blue
6.	Green	Data RX-	6.	Green	6.	Orange
7.	White Brown		7.	White Brown	7.	White Brown
8.	Brown		8.	Brown	8.	Brown