Linux Facts to Ponder

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

hdparm tests hdd disk speed, which should be above 10Mb/s

 

 

 

ISA plug and play is controlled via /etc/isapnp.conf

 

 

 

 

pnpdump > isapnp.conf .. Produces an editable isapnp.conf file

 

 

 

kernel oopses log to /var/log/messages

 

 

 

 

 

dmesg displays the contents of the kernel ring buffer

 

 

 

 

setserial -a /dev/Stty01  gives configuration report on serial1 / comm1

 

 

lsof  … lists open files

 

 

 

 

 

 

password encoding methods are DES and lately MD5

 

 

 

 

the DOS utility rawrite creates linux boot disc

 

 

 

 

Ctrl Z then bg puts a process into the background

 

 

 

 

alien can convert tarball to debian or rpm format

 

 

 

 

alien syntax # alien --to-rpm filename-1.2.3-4-i386.deb

 

 

 

boot loaders are located in the mbr

 

 

 

 

 

boot loaders are lilo, grub, ntldr and loadlin

 

 

 

 

 

XF86config file contains Sections such as Monitor, Device, Screen etc

 

 

the XF86Config Screen Section contains Display Subsections

 

 

 

XF86config : Display specifies Modes and Depths

 

 

 

 

XF86config : Monitor specifies Modeline and Refresh rates

 

 

 

ADSL = asymetric digital subscriber line (broadband)

 

 

 

 

APPOE = ppp over ethernet (ip address assignment)

 

 

 

 

/etc/fstab  dump=1  means a partition is backed up

 

 

 

 

the fstab columns are : device, mount point, filesystem, option, dump, fsck

 

 

use rawrite to copy boot.img to floppy on Dos system

 

 

 

dd can also be used to produce a bootable floppy

 

 

 

 

lilo boots the first stanza if no default is specified

 

 

 

 

lilo should not be in the mbr to prevent it from being overwritten

 

 

 

the mbr is on the first sector of a hdd

 

 

 

 

 

the rpm and debian databases are stored in /var/lib/xxx

 

 

 

user programs compiled from source code are kept in /usr/local

 

 

 

CDE is the commercial desktop environment for linux

 

 

 

 

widget sets (for gui interface) are Qt from Trolltech, and GTK+

 

 

 

KDE uses Qt, and Gnome uses Gtk+ widget sets

 

 

 

 

user names may be up to 32 characters long (pref 8)

 

 

 

 

etc/sudoers specifies who may run what with root rights

 

 

 

find /-perm +ug+s  finds all SUID and SGID program files

 

 

 

syslog.conf  contains the configuration for log files

 

 

 

 

logcheck.sh mails certain log entries to root

 

 

 

 

etc/resolv.conf requires at least one nameserver entry for DNS queries

 

 

/usr/sbin/tcpd (tcp wrappers) is configured in /etc/hosts.allow    hosts.deny

 

 

inetd calls tcpd to check authorisation of incoming and outgoing tcp/ip calls

 

 

runlevel -q  causes system to read /etc/inittab file

 

 

 

 

runlevel -s  brings the system to single user mode

 

 

 

 

fdisk -l /dev/sda lists all partitions on the first scsi drive

 

 

 

FHS replaces FSSTND as the linux file system standard

 

 

 

FHS specifies that directories such as /etc /sbin must reside in root filesystem

 

to view a core dump type : gdb -c core

 

 

 

 

 

a backslash "/ " at the command line signals a line continuation

 

 

 

ghostscript smartfilters are specified in /etc/printcap as if [input filters]

 

 

drivers are set either in lilo.conf [append/kernel option] or modules.conf /options

 

hdparm -d1 enables DMA mode for EIDE data transfer

 

 

 

hdparm can test scsi but not set scsi

 

 

 

 

 

updatedb refreshes the locate database