Inhaltsverzeichnis
Linux
SuSE
LINUX SuSERedhat
LINUX Redhat?Ubuntu
LINUX Ubuntuusefull Konfigurations
Master Boot Record
Der Master Boot Record (kurz MBR) bzw. Partitionssektor ist bei BIOS-basierten Computern der x86-Architektur der erste Datenblock (512 Byte) eines in Partitionen aufgeteilten Speichermediums, wie beispielsweise einer Festplatte. Der MBR enthält eine Partitionstabelle, die die Aufteilung des Datenträgers beschreibt, und optional einen Boot-Loader, ein Programm, das ein Betriebssystem auf einer der Partitionen startet.siehe Wikipedia Artikel:
http://de.wikipedia.org/wiki/Master_Boot_Record#GRUB
raid configuration
raid on disks greater 2TB
setting up raid with gpt for disks greater 2TBparted is a replacement for fdisk of Linux. It can handle disks larger than 2 TB. Issue this command to launch parted where /dev/sdX is the disk you want to initialize.
parted /dev/sdX
create a new gpt disklabel (partition table)
mktable gpt
To create a new partition, mkpart is used to do so. This parted command creates a primary ext4 partition, starting at the first cylinder to the last sector of the disk.
mkpart primary 1 -1
set raid Label on new defined partition, print result and quit.
set 1 raid on
quit
or
parted /dev/sdX "mktable gpt" parted /dev/sdX "mkpart primary 1 -1" parted /dev/sdX "set 1 raid on" parted /dev/sdX "print"
Deleting a Linux Software Raid Array
In this case partitions on 2 SATA drives had been accidentally forced into a md0 RAID1 array.Stop the array:
mdadm --stop /dev/md0
Delete the array:
mdadm --remove /dev/md0
Zero the superblocks:
mdadm --zero-superblock /dev/sdb1 mdadm --zero-superblock /dev/sdc1
re-create /etc/mdadm/mdadm.conf
save your current configuration
mv /etc/mdadm/mdadm.conf /etc/mdadm/mdadm.conf_`date +%y%m%d`
and create new file
echo "#New RAID SCAN" > /etc/mdadm/mdadm.conf mdadm --examine --scan >> /etc/mdadm/mdadm.conf
Linux video mode numbers
The Linux kernel allows user configuration of VESA modes at boot time using the vga kernel parameter. This parameter does not directly accept VESA video mode numbers; instead, a Linux video mode number must be calculated using the VESA number.To calculate the Linux video mode number add 512. The resulting decimal value can be passed to the kernel in the form 'vga=XXX', where XXX is the decimal value, or in form 'vga=0xHHH', where HHH is the hexadecimal value. This calculation is not always accurate. It is a good starting point and you may have to do some experimenting to find the correct value.
> Farbtiefe | 320x200 | 640x400 | 640x480 | 800x500 | 800x600 | 896x672 | 1024x640 | 1024x768 | 1152x720 | 1280x1024 | 1400x1050 | 1440x900 | 1600x1200 | 1920x1200 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
16colors | 770 | 772 | 774 | |||||||||||
256collors | 768 | 769 | 879 | 771 | 815 | 874 | 773 | 869 | 775 | 835 | 864 | 796 | 893 | |
15-bit(5:5:5) | 781 | 801 | 784 | 880 | 787 | 816 | 875 | 790 | 870 | 793 | 865 | 797 | ||
16-bit(5:6:5) | 782 | 802 | 785 | 881 | 788 | 817 | 876 | 791 | 871 | 794 | 837 | 866 | 798 | |
24-bit(8:8:8) | 783 | 803 | 786 | 882 | 789 | 818 | 877 | 792 | 872 | 795 | 838 | 867 | 799 | |
32-bit(8:8:8) | 804 | 809 | 883 | 814 | 819 | 878 | 824 | 873 | 829 | 868 | 834 |
usefull commands
sudo
sudo Konfiguration
Beispiel für eine sudo Konfiguration# # Sample /etc/sudoers file. # # This file MUST be edited with the 'visudo' command as root. # # See the sudoers man page for the details on how to write a sudoers file. # ## # User alias specification ## User_Alias FULLTIMERS = millert, mikef, dowdy User_Alias PARTTIMERS = bostley, jwfox, crawl User_Alias WEBMASTERS = will, wendy, wim ## # Runas alias specification ## Runas_Alias OP = root, operator Runas_Alias DB = oracle, sybase ## # Host alias specification ## Host_Alias SPARC = bigtime, eclipse, moet, anchor:\ SGI = grolsch, dandelion, black:\ ALPHA = widget, thalamus, foobar:\ HPPA = boa, nag, python Host_Alias CUNETS = 128.138.0.0/255.255.0.0 Host_Alias CSNETS = 128.138.243.0, 128.138.204.0/24, 128.138.242.0 Host_Alias SERVERS = master, mail, www, ns Host_Alias CDROM = orion, perseus, hercules ## # Cmnd alias specification ## Cmnd_Alias DUMPS = /usr/sbin/dump, /usr/sbin/rdump, /usr/sbin/restore, \ /usr/sbin/rrestore, /usr/bin/mt Cmnd_Alias KILL = /usr/bin/kill Cmnd_Alias PRINTING = /usr/sbin/lpc, /usr/bin/lprm Cmnd_Alias SHUTDOWN = /usr/sbin/shutdown Cmnd_Alias HALT = /usr/sbin/halt, /usr/sbin/fasthalt Cmnd_Alias REBOOT = /usr/sbin/reboot, /usr/sbin/fastboot Cmnd_Alias SHELLS = /usr/bin/sh, /usr/bin/csh, /usr/bin/ksh, \ /usr/local/bin/tcsh, /usr/bin/rsh, \ /usr/local/bin/zsh Cmnd_Alias SU = /usr/bin/su Cmnd_Alias VIPW = /usr/sbin/vipw, /usr/bin/passwd, /usr/bin/chsh, \ /usr/bin/chfn ## # Override built-in defaults ## Defaults syslog=auth Defaults:FULLTIMERS !lecture Defaults:millert !authenticate Defaults@SERVERS log_year, logfile=/var/log/sudo.log ## # User specification ## # root and users in group wheel can run anything on any machine as any user root ALL = (ALL) ALL %wheel ALL = (ALL) ALL # full time sysadmins can run anything on any machine without a password FULLTIMERS ALL = NOPASSWD: ALL # part time sysadmins may run anything but need a password PARTTIMERS ALL = ALL # jack may run anything on machines in CSNETS jack CSNETS = ALL # lisa may run any command on any host in CUNETS (a class B network) lisa CUNETS = ALL # operator may run maintenance commands and anything in /usr/oper/bin/ operator ALL = DUMPS, KILL, PRINTING, SHUTDOWN, HALT, REBOOT,\ /usr/oper/bin/ # joe may su only to operator joe ALL = /usr/bin/su operator # pete may change passwords for anyone but root on the hp snakes pete HPPA = /usr/bin/passwd [A-z]*, !/usr/bin/passwd root # bob may run anything on the sparc and sgi machines as any user # listed in the Runas_Alias "OP" (ie: root and operator) bob SPARC = (OP) ALL : SGI = (OP) ALL # jim may run anything on machines in the biglab netgroup jim +biglab = ALL # users in the secretaries netgroup need to help manage the printers # as well as add and remove users +secretaries ALL = PRINTING, /usr/bin/adduser, /usr/bin/rmuser # fred can run commands as oracle or sybase without a password fred ALL = (DB) NOPASSWD: ALL # on the alphas, john may su to anyone but root and flags are not allowed john ALPHA = /usr/bin/su [!-]*, !/usr/bin/su *root* # jen can run anything on all machines except the ones # in the "SERVERS" Host_Alias jen ALL, !SERVERS = ALL # jill can run any commands in the directory /usr/bin/, except for # those in the SU and SHELLS aliases. jill SERVERS = /usr/bin/, !SU, !SHELLS # steve can run any command in the directory /usr/local/op_commands/ # as user operator. steve CSNETS = (operator) /usr/local/op_commands/ # matt needs to be able to kill things on his workstation when # they get hung. matt valkyrie = KILL # users in the WEBMASTERS User_Alias (will, wendy, and wim) # may run any command as user www (which owns the web pages) # or simply su to www. WEBMASTERS www = (www) ALL, (root) /usr/bin/su www # anyone can mount/unmount a cd-rom on the machines in the CDROM alias ALL CDROM = NOPASSWD: /sbin/umount /CDROM,\ /sbin/mount -o nosuid\,nodev /dev/cd0a /CDROM