SysAdmin Blog, TechTips and Reviews

An (ex) System Administrator's Blog



Archives Posts

UNIX 10 Good Habits

January 29th, 2008 by elizar

Got this tips from the people at IBM.

These tips are a must not only for System Administrators but also for all UNIX users.

Ten good habits to adopt are:

  1. Make directory trees in a single swipe.
  2. Change the path; do not move the archive.
  3. Combine your commands with control operators.
  4. Quote variables with caution.
  5. Use escape sequences to manage long input.
  6. Group your commands together in a list.
  7. Use xargs outside of find.
  8. Know when grep should do the counting — and when it should step aside.
  9. Match certain fields in output, not just lines.
  10. Stop piping cats.
Filed under Tips having No Comments »

Archives Posts

NFS server CDM Server not responding still trying

January 23rd, 2008 by elizar

When listing mounted file system (df -k), it apparently freezes and displays:

 NFS server CDM Server not responding still trying

also when trying to change directory to /ctxmnt, the same error occurs

Not responding error message

In the unlikely event that the client drive mapping process on the server is slow in responding, an error (such as “NFS server CDM server not responding still trying” or “NFS server 127.0.0.1 not responding still trying” ) is displayed.

Normally, this request is fulfilled and the message “NFS server CDM server ok” or “NFS server 127.0.0.1 ok” is displayed. However, if the problem persists, you must restart the client drive mapping process on the server.

Tip To interrupt the request and get a command prompt, press CTRL and C, or send a SIGINT to the process.

To restart client drive mapping

1. Ensure that there are no users in the /ctxmnt directory (users should not be reading or writing to this directory, nor should it be their current directory). For example, you may want to ask your users to log off from the MetaFrame server—to do this, use the ctxmsg -a command to send a message to all users.

2. Stop client drive mapping. At the command prompt, type:

ctxsrv stop cdm

3. Restart client drive mapping. At the command prompt, type: ctxsrv start cdm

Filed under Tips having No Comments »

Archives Posts

General Asterisk Installation Instructions

January 22nd, 2008 by elizar

After reading the Asterisk Overview a few post back, let’s continue with our adventure in the world of Asterisk – the open source telephone toolkit.

We need to do two things (that is, two steps) in order install Asterisk on our vmware powered Red hat enterprise server:

  1. Get the source code
  2. Compile to produce the binaries

http://www.asteriskguru.com/tutorials/general_asterisk_installation_compilation.html

Get the Source Code

Click the links below to get a copy of Asterisk

Asterisk 1.2.4
Zaptel 1.2.4
Libpri 1.2.2

Asterisk-sounds 1.2.1 – Additional sound prompts
Asterisk-addons 1.2.1 – Additional modules
Or to get the latest version with the latest update, get the source of Asterisk from the CVS server:

To get a fresh copy from the CVS server use these commands:

# cd /usr/src
#mkdir asterisk
# export CVSROOT=:pserver:anoncvs@cvs.digium.com:/usr/cvsroot
# cvs login

Compiling Asterisk

To install Asterisk, we need to update (if you donwloaded the source) and change to that asterisk directory. Example:

#cd /usr/src/asterisk

You can then start the compiling process…
Follow this installation order: libpri, zaptel, asterisk

-Installing libpri

#cd /usr/src/asterisk/libpri
#make clean
#make
#make install

-Installing zaptel

#cd /usr/src/asterisk/zaptel
#make clean

Note: If you are using kernel 2.6 enter the following command ‘#make linux26’, before doing ‘#make install’.

#make install

-Installing asterisk

#cd /usr/src/asterisk/asterisk
#make clean

Note: If you want to use a mp3 files for music-on-hold enter the following command ‘#make mpg123’, before doing ‘#make install’.

#make install

If this is your first installation perform ‘make samples’ to install sample configuration files.

Filed under VoIP having 1 Comment »

Archives Posts

Sun Microsystems Owns Mysql AB

January 17th, 2008 by elizar

Here’s the news that everyone involved in IT should know by now – Sun Microsystems bought Mysql AB!

For those who doesn’t know, MySQL AB is  the company behind MySQL, the world’s most popular open source database.

From the blog of Sun Microsystems’ CEO, Jonathan Schwartz‘ :

We announced big news today – our preliminary results for our fiscal second quarter, and as importantly, that we’re acquiring MySQL AB.

we’re putting a billion dollars behind the M in LAMP.

With this ground breaking event, I’m sure there will be some far out development in Mysql/Sun in the near future.

Filed under IT News, Open Source having 1 Comment »

Archives Posts

AsteriskNOW – Asterisk Out Of The Box

January 16th, 2008 by elizar

I recently found a nice read about a Linux Project or Distro that includes Asterisk. It contains all the Asterisk stuff one will ever need. The project is called AsteriskNOW.

You can donwload the package at asteriskNOW.com. You can choose to download and ISO image or a VMWare image on the donwload page.

The is so easy to use and install that AsteriskNOW claims that you can install it 30 minutes!

Read the rest of this entry »

Filed under Linux, VoIP having No Comments »

Archives Posts

Game Time! Sysads’ Break

January 15th, 2008 by elizar

What do most sysads do during they idle time? We could play tennis, badminton, soccer, basketball and other physical sports, but no! Some of us, though more that 12 hours in front of a computer terminal still prefers to play computer games, either PC games or mac games or both!

Introducing Midoritech

Tons of games can be found in the internet.

At midoritech.com there are many games to choose from there’s the classic solitaire, a mahjong, and a couple of Games for kids. One particular game that is truly relevant is all about global warning !

Head on over to the site and check out them cool games! :)

Filed under Uncategorized having No Comments »

Archives Posts

Perl One Liner: Search and Replace for LDAP ldif file

January 14th, 2008 by elizar

Quick post… note to self…

In resetting passwords for one of our customers, we have to create the necessary LDIF file (yep, system uses LDAP), and do the ldapmodify command.

Instead of creating ldif file (or editing existing) every time there is a password reset, why ‘vi’ every time when you can do a one line perl command to replace the ‘uid’ part of the LDIF file?

Example:

After checking that the password was indeed locked, we create an LDIF file like this one:

# more /tmp/ldif.txt
dn: uid=guttekg,ou=people,dc=domain,dc=domain2,dc=domain3,dc=com
changetype: modify
replace: userPassword
userPassword: R3s#tn9

and execute the ldapmodify command:

ldapmodify -D “cn=Directory Manager” -h ldap_server -f /tmp/ldif.txt

For the next password reset, we don’t have to do ‘vi’ and edit the ldif file. Simpley do:

perl -p -i -e ‘s/oldstring/newstring/g’ *

.. and we’re done.. (after the ldapmodify of course)

Filed under Tips having No Comments »

Archives Posts

Asterisk Overview: An Open Source VoIP Application

January 13th, 2008 by elizar

Asterisk is an open source application on telephony applications and a full-featured call-processing server. It’s is one of the last technology that has been in existence too long that the open source group has touched on.

There has been and open source web server (Apache), mail server (qmail, sendmail, postfix etc), proxy server (squid), CMS (joomla, wordpress), streaming media (icecast) but never, until now, has anyone every tried offering voice application to the open.

Good thing about Asterisk is that it can be used as a stand alone, Asterisk-Only system, or it can integrate with an existing PBX system.

Features of Asterisk Open Source PBX

Asterisk has tons of feature that could take my whole day listing and explaining them here. Let’s just say that everything you ever knew about PBX capabilities are also in Asterisk.

Let’s list a couple for example’s sake:

  • Call Forward
  • Call Forward on Busy
  • Call Forward on No Answer
  • Call Monitoring

Read the rest of this entry »

Filed under VoIP having 6 Comments »

I was here...