I hope you won’t need this instructions but in case you have some problems …

First, keep in mind that running fsck on a mounted file system can result in data corruption so use this commands at your own risk. I’m not responsible for any damage you may cause.

To avoid this, you can:

• Change the running state of the system to single user mode and unmount the file system

(Note: Skip this option if you need to check / part.)

• Boot the computer into Rescue Mode using the installation CD

1) Single user mode

Change the run level to 1 and unmont the file system with (I suppose the /home was affected with problems)

# init 1
# umount /home

Then run fsck with

# fsck /dev/sda2

2) Rescue mode with install CD

Insert the Installation CD into the drive and reboot your system with

# reboot

Wait a while and after booting from the Installation CD type in command prompt:

# linux rescue nomount

Note: nomount directive will skip mounting so you can safely run fsck on your filesystem

Then enter

# fsck -yvf /dev/sda2

where /dev/sda2 is problematic partition.
Note: -yvf means
-y attempt to fix any detected filesystem corruption automatically (answer all questions with “yes”)
-f force a check even if reported in a clean state
-v verbose output, including all file system-specific commands that are executed (you will see all errors and recovery process)

LVM Partitions
Situation with LVM partitions is a little different. To run fsck on lvm partitions first you need to find the pv’s, vg’s, lv’s and then to activate them.

# lvm pvscan
# lvm vgscan
# lvm lvchange -ay VolGroup00
# lvm lvscan
 
# fsck -yfv /dev/VolGroup00/LogVol00

fsck can be scheduled on boot with

# shutdown -Fr now

In other words, amavisd-new will help you to fight against spam. In this post, I won’t write about installation (coming soon in you theaters)

This post is just a small trick which will help you to release specific message from quarantine (false positive or you simple want to read spam messages)

Fist you need to find message inside the messages log file (usually /var/log/messages)

May 10 10:06:56 ns1 amavis[12774]: (12774-13) Blocked SPAM, [207.46.22.35] [207.46.22.35] <cnfrmpro@microsoft.com> -> <mymail@domain.tld>, quarantine: spam-1lvc624m6MVB.gz, Message-ID: <BY2MSFTVSMTP03Dfn8e0003d305@by2msftvsmtp03.phx.gbl>, mail_id: 1lvc624m6MVB, Hits: 7.743, size: 3013, 4325 ms

As you can see above, it is spam-1lvc624m6MVB.gz

Now you can release specific message with

[root@s1 ~]# amavisd-release spam-1lvc624m6MVB.gz

And you will see something like

250 2.0.0 Ok, id=rel-1lvc624m6MVB, from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as 403206AF07CE

Now you just need to check your inbox and you should see the message.

Few days ago I noticed that one server doesn’t send logwatch email. I wanted to see what was the reason and here are the few tips you can check before you dig inside logwatch settings.

First, check /etc/aliases and root email inside

# nano /etc/aliases

at the end, check next lines:

# Person who should get root's mail
root:           blabla@domain.tld

After you save aliases, enter command

# newaliases

This command rebuilds the random access data base for the mail aliases file /etc/aliases. It must be run each time this file is changed in order for the change to take effect. This would be enough to receive all email directed to root, but in case you still don’t get root emails, check mta with:

# alternatives --display mta

This will show you something like

[root@s1 ~]# alternatives --display mta
mta - status is manual.
 link currently points to /usr/sbin/sendmail.sendmail
/usr/sbin/sendmail.sendmail - priority 90
 slave mta-pam: /etc/pam.d/smtp.sendmail
 slave mta-mailq: /usr/bin/mailq.sendmail
 slave mta-newaliases: /usr/bin/newaliases.sendmail
 slave mta-rmail: /usr/bin/rmail.sendmail
 slave mta-sendmail: /usr/lib/sendmail.sendmail
 slave mta-mailqman: /usr/share/man/man1/mailq.sendmail.1.gz
 slave mta-newaliasesman: /usr/share/man/man1/newaliases.sendmail.1.gz
 slave mta-aliasesman: /usr/share/man/man5/aliases.sendmail.5.gz
 slave mta-sendmailman: /usr/share/man/man8/sendmail.sendmail.8.gz
/usr/sbin/sendmail.postfix - priority 30
 slave mta-pam: /etc/pam.d/smtp.postfix
 slave mta-mailq: /usr/bin/mailq.postfix
 slave mta-newaliases: /usr/bin/newaliases.postfix
 slave mta-rmail: /usr/bin/rmail.postfix
 slave mta-sendmail: /usr/lib/sendmail.postfix
 slave mta-mailqman: /usr/share/man/man1/mailq.postfix.1.gz
 slave mta-newaliasesman: /usr/share/man/man1/newaliases.postfix.1.gz
 slave mta-aliasesman: /usr/share/man/man5/aliases.postfix.5.gz
 slave mta-sendmailman: /usr/share/man/man1/sendmail.postfix.1.gz
Current `best' version is /usr/sbin/sendmail.sendmail.

We use postfix so we should change this with

[root@s1 ~]# alternatives --config mta
 
There are 2 programs which provide 'mta'.
 
  Selection    Command
-----------------------------------------------
*+ 1           /usr/sbin/sendmail.sendmail
   2           /usr/sbin/sendmail.postfix
 
Enter to keep the current selection[+], or type selection number:

Enter 2 and press Enter. Then check your mta with

[root@s1 ~]# alternatives --display mta
mta - status is manual.
 link currently points to /usr/sbin/sendmail.postfix

That’s it… Now if your logwatch is configured properly you should receive root emails…

For RHEL5 / CentOS-5:
i386

# wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.1-1.el5.rf.i386.rpm
# rpm -Uvh rpmforge-release-0.5.1-1.el5.rf.i386.rpm

x86_64

# wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.1-1.el5.rf.x86_64.rpm
# rpm -Uvh rpmforge-release-0.5.1-1.el5.rf.x86_64.rpm

For older releases (RHEL 4 / CentOS 4) please follow the instructions available on RPMrepo Wiki

[root@hydra:~]# cat /etc/redhat-release
CentOS release 5.2 (Final)

Fedora sample:

[root@s2 ~]# cat /etc/redhat-release
Fedora release 7 (Moonshine)

So, if you don’t want to build rpms or to go through ./configure, make, make install nightmare, you can enable Jason Litka yum repository to your RHEL or CentOS system. To do this please follow next few steps.

First you need to validate that the packages came from Jason Litka and you’ll do it with next command:

#rpm --import http://www.jasonlitka.com/media/RPM-GPG-KEY-jlitka

After you added his public GPG key, you’ll need to adjust yum so he can search at his repo. To do this, please follow next steps:

#nano -w /etc/yum.repos.d/utterramblings.repo

Now copy next lines inside this file and save those changes.

[utterramblings]
name=Jason's Utter Ramblings Repo
baseurl=http://www.jasonlitka.com/media/EL$releasever/$basearch/
enabled=1
gpgcheck=1
gpgkey=http://www.jasonlitka.com/media/RPM-GPG-KEY-jlitka

Now you can upgrade your PHP installation with simple:

#yum update php

More information about this can be found HERE.

#php -v

should return

[root@ns1 ~]# php -v
PHP 5.2.6 (cli) (built: May  5 2008 10:32:59)
Copyright (c) 1997-2008 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2008 Zend Technologies
[root@ns1 ~]#

I forget to say that you should restart httpd after upgrade.