can anyone tell me please...

Sarah,

Could you tell me if nslookup works on server with the broken yum?

Try with

nslookup mirror.centos.org ipofyournameserver

if it replies.

I saw another post by you about the webserver reolving to 127.0.0.1 and am guessing if fault dns could have been the cause.
On the same token, what's the content of /etc/resolv.conf on that server with the faulty yum?

You also mentioned your boss uses a http proxy. Any chance you try setting yum to use the http proxy?

Almost running out of ideas, i would suggest you reinstall yum i.e: download the yum rpm to the server or extract it from a centOS dvd, rpm remove yum and then rpm install it back again.

In that case can you post your

well the output of /ect/resolv.conf for the server with faulty yum is:
search tashicell.com

nameserver 118.103.137.1
nameserver 118.103.136.65
nameserver 118.103.136.67


and the output of yum.conf is:
[main]
cachedir=/var/cache/yum
keepcache=0
debuglevel=2
logfile=/var/log/yum.log
distroverpkg=redhat-release
tolerant=1
exactarch=1
obsoletes=1
gpgcheck=1
plugins=1
bugtracker_url=http://bugs.centos.org/set_project.php?project_id=16&ref=http://b
ugs.centos.org/bug_report_page.php?category=yum

# Note: yum-RHN-plugin doesn't honor this.
metadata_expire=1h

installonly_limit = 5

# PUT YOUR REPOS HERE OR IN separate files named file.repo
# in /etc/yum.repos.d

and the output for /etc/yum/repos.d/Centos-Base.repo is:
# CentOS-Base.repo
#
# This file uses a new mirrorlist system developed by Lance Davis for CentOS.
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#

[base]
name=CentOS-$releasever - Base
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo
=os
#baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
gpgcheck=1
priority=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5

#released updates
[updates]
name=CentOS-$releasever - Updates
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo
=updates
#baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/
gpgcheck=1
priority=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5

#packages used/produced in the build but not released
[addons]
name=CentOS-$releasever - Addons
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo
=addons
#baseurl=http://mirror.centos.org/centos/$releasever/addons/$basearch/
gpgcheck=1
priority=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5

#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo
=extras
#baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/
gpgcheck=1
priority=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5

#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo
=centosplus
#baseurl=http://mirror.centos.org/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=1
priority=2
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5

#contrib - packages by Centos Users
[contrib]
name=CentOS-$releasever - Contrib
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo
=contrib
#baseurl=http://mirror.centos.org/centos/$releasever/contrib/$basearch/
gpgcheck=1
enabled=1
priority=2
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5

Aazkan this is th error that i get when i do "yum check-update":

Loading mirror speeds from cached hostfile
Could not retrieve mirrorlist http://mirrorlist.centos.org/?releas...86&repo=addons error was
[Errno 4] IOError: <urlopen error (110, 'Connection timed out')>
Error: Cannot find a valid baseurl for repo: addons

Your yum.conf and repos looks ok, nothing obviously wrong.

How comfortable are you with command lines to remove, download and install yum?
If you think your willing to have a go, i'll see to guiding you through.

I cant gurantee this will fix the problem but we'll at least be certain yum after reinstall will theoratically working out of the box.

I'll be out to fetch my son from his play school and out to be back online in an hour or so. Let me know if you want to give this a shot.

wow thanks aazkan,that is really nice of you..

ya i would like to try this out but want you guiding me throughout as well...

Or is something wrong with my base url of the addons,because the error says that the "Could not retrieve mirrorlist http://mirrorlist.centos.org/?releas...86&repo=addons " ,and i went to this url it returns 404 error..

I think all you need to do is turn

in all the sections and try

well in the other servers i.e the slave servers,enabled has been set to 1,yum check-update is still working...

it's only the primary nameserver which is having this problem..

there's no harm in trying

and if it doesn't works then it goes again to resolv.conf

thanks deepak but i don't know what is wrong with my vi editor, m not able to save the changes...

i went to insert mode and made the changes and typed :wq to save the changes and exit but it isnt happening..am i wrong?

what is the error you are getting?

check the permissions on file

take a backup of the .repo file at some place and then change the permission as root user, then give it a try

well deepak i did as u said...vi worked,it was my mistake that it didnt work that time....


even after putting 0 to enabled that command didnt work..

did you tried this command


are you able to list all yum?

ya i tried the first two commands,it gives the same problem still..

and yum list command is also not working,it gives the same error..