Introduction

This page has information about "light touch" (as opposed to systems up to Fedora Core 3) management of machines loaded with distributions based on RedHat, such as CentOS (a free Enterprise Linux distribution) and Fedora Core (latest code). They are being used as the RedHat style distribution for user WSs, and for dom0 xen servers. As they are built from the same code base and have very similar file names and mechanisms, it is hoped that whichever distribution is more functional can be used with very similar, minimal tailoring.

There is a separate page for User Admins who can perform certain admin tasks on their own machines, and one for root Admin which covers things such installation, intergation, and admin tasks which can be performed by root.

Please feel free to add or correct anything, having read the WiKiHints

Additional local CL commands

To avoid possible name clashes, and to let users know when they are using local CL extensions, most local additions have the prefix "cl-". As an example, we have a local wrapper to call the rdesktop command to ensure we use the licences correctly. The standard distribution installed command remains rdesktop, and the local addition is cl-rdesktop. A full list of such commands should be available on many shells by typing "cl-" and then pressing the "command complete" character (usually TAB). The most common commands are:

Exceptions to this are standard commands which use a local RPM, and use the standard command names. These include:

Known features

Below are some known "features" which users may come across

java vs javac

FC6 comes with a free (as in speech) java RPM java-1.4.2-gcj-compat which uses the alternatives mechanism to install itself as /usr/bin/java. If the Sun jdk is installed, it creates links in /usr/bin/ if they do not already exist, e.g. it creates /usr/bin/javac. Thus if a user naively compiles using "javac" and runs using "java", the 1.4 system will try to run a programme compiled by 1.6 and may fail. As such, take care to use compatible binaries, e.g. by putting /usr/java/default/bin on your PATH before /usr/bin.

LANG is en_GB.UTF-8

The system default is to use UTF-8, If this causes prolems (characters look wrong, xterms start slowly, etc) see some local notes. The include the recommendation to set

export LC_COLLATE=C

so that sorting is more conventional and reduce some chances for accidental file deletion.

printing from gnome apps (acroread, firefox, etc) defaults to "letter" paper

https://launchpad.net/distros/ubuntu/+source/libgnomeprint/+bug/34112 reports a generic bug in gnome applications not using the correct default settings.

Fix: Select configure and set the correct paper etc.

Firefox does its own printing - it doesn't use KDE or Gnome - and refuses to save the paper size. A hacky way to fix this:

acroread: 'failed due to unknown user id'

If acroread reports something like

 GLib-WARNING **: getpwuid_r(): failed due to unknown user id (104)

this means that the application isn't using /etc/nsswitch.conf, so implicitly using just the file value for passwd. A HACK to get round this is to ensure that nscd is running. To request that it is started, check for 5:on from chkconfig

slogin-serv3:~: /sbin/chkconfig nscd --list
nscd            0:off   1:off   2:off   3:on    4:on    5:on    6:off
slogin-serv3:~: /sbin/service nscd status
nscd dead but subsys locked
slogin-serv3:~: 

If, as above, nscd isn't running, the User Admin can restart it using "cl-asuser service nscd restart".

Differences for ex-FC3 users

As above, most locally written Lab additional commands now start with the prefix "cl-", so try them first.

Alternative commands

Some commands from old systems are no longer available, but alternative ones are (ones in italics can be loaded, but are not by default)

Changed default configurations

Some command settings which were tailored under FC3 now use the defaults from the distribution. These include

New printing system: CUPS

The printing system is CUPS based rather than using the old CL LPRng system.

Some applications are currently wasteful on paper as non-duplex printing is the default and text files use large fonts.

Note that the information provided by the lpr command is very limited. More details may be available by connection to the CUPS web interface.

The tailor file ~/.cups/lpoptions (or if it does not exist, ~/.lpoptions) is read.

WiFi connections

To connect using WiFi, use the wifi-radar command, rather than editing /etc/user-config/where.

Window manager selection

The old system use switchdesk to select which window manager to use for each user. The new system allows the user to select using the login GUI. Select "Options -> session" and select the Window Manager to use. If yours is not listed, it may need to be loaded (e.g. login to VC1 and type "cl-asuser yum install -y fvwm). Users of non standard and old Window Managers may want to consider using a newer one, as the old ones may cease working at any point. xfce is a fairly lightweight option if users don't want megabloat such as KDE or Gnome.

If a non default one is selected, when you have logged in, it'll ask you whether you want to make it the default for future sessions.

Tailoring to make it more like FC3

The tailoring is minimal, giving the default for the distribution. FC3 users requiring similar settings may consider the following

mh

Tweaks include ~/.mh_profile having "Editor: prompter", "Editor-next: vi", "repl: -group". The default components, forwcomps, replcomps and replgroupcomps in /etc/nmh/ include "Fcc: +outbox" causing output to be copued to outbox. To suppress this, copy the files into ~/Mail/ and remove the lines.

exmh

To enable "Forward as MIME", add to the beginning of ~/.exmh/exmh-defaults the lines

! Glenn Vanderburg <glv@utdallas.edu>
! This sets things up so that I can use MIME-style forwarding ...
*Mops.umenulist:               forwmenu
*Mops.forwmenu.text:             Forw..
*Mops.forwmenu.m.entrylist:      forwmime forw
*Mops.forwmenu.m.l_forwmime:     Forward using MIME <Key-f>
*Mops.forwmenu.m.c_forwmime:     Msg_Forward -mime
*Mops.forwmenu.m.l_forw:         Forward (old-style) <Key-F>
*Mops.forwmenu.m.c_forw:         Msg_Forward
! And this line is an echo of the equivalent line in the app-defaults file,
! with the forward button removed, since we've replaced it with a menu.
*Mops.buttonlist:               link move delete next prev comp

mh-e

It is believed that deleting line starting "(setq mh-" should make it use suitable defaults. Otherwise try adding lines such as

(setq mh-lib-progs "/etc/nmh")
(setq mh-lib "/usr/libexec/nmh")
(setq mh-comp-formfile "/etc/nmh/components")
(setq mh-repl-formfile "/etc/nmh/replcomps")

SysInfo/RedhatLite (last edited 2009-10-14 21:04:19 by PieteBrooks)