100Mbps up-link port is standard nowadays even for a low cost dedicated servers or  server co-location. When your web site visitors increase or you are landing Digg or Yahoo! front page a 100Mbps up-link will simply not cope with the load. If you upstream provider offers 1Gbps ports – go for it if your MRTG shows maxing out (or even 80Mbps or so peak time usage) 100Mbps up-link from time to time.

If your upstream provider doesn’t offer 1Gbps links and your server has two NIC ports, you can set-up link aggregation (network bonding) with IEEE 802.3ad mode and increase … Read the rest of this entry »

To speed up your new Suse Linux Enterprise Server (SLES) install process and register your new box with Novell Center I suggest using a quick command line:

suse_register -a email=”your@emailaddresshere.com” -a regcode-sles=”REGCODE”

REGCODE is your Suse registration code (e.g. Order code), usually consists of 14 characters.

You must be root to execute this command and make sure you network configuration is set-up and your server on-line. After registration you can start server updating process via Yast or rug command line. Good luck!… Read the rest of this entry »

Hey folks… If you are experiencing the following error:

`-mcpu=’ is deprecated. Use `-mtune=’ or ‘-march=’ instead.

I would do the following to avoid it:

CFLAGS=”-mtune=i686″ CXX=gcc CXXFLAGS=”-mtune=i686″ ./configure ….

… Read the rest of this entry »

We have been experiencing updating problems on SLES 10 SP 2 box and here is the error we got:

ERROR: Failed to download XML metadata: Download failed: (https://nu.novell.com/repo/repoindex.xml) Invalid certificate received form server.

To fix the problem do the following.

Open /etc/zmd/zmd.conf file that will look something like this:

[Advanced]
run-transaction-test=False
security-level=signature

[Server]
bind-ip=127.0.0.1
software-inventory-enabled=False
refresh-interval=86400
remote-enabled=false
require-verified-certs=True
hardware-inventory-enabled=False

[Network]
proxy-url=
proxy-password=
proxy-username=

[Cache]
cache-max-size-in-mb=300

[Debug]
log-soap-xml=False
log-exception-traces=False

and replace

require-verified-certs=True

with

require-verified-certs=False

… Read the rest of this entry »

Many folks ask us what is the best platform/OS for web hosting platform? Is it Centos, FreeBSD, Gentoo, Suse or Fedora. While, Centos, FreeBSD, Fedora is more common in USA, SUSE beats deployment statistics in Europe – Germany. Finding Suse and Gento from USA dedicated server companies is somewhat tricky. I am of course not speaking about virtual private servers.

I don’t like much Fedora either because of quick end-of-life (EOF) for updates and upgrading usually costs money, requires downtime and somewhat complex for novice users. So we have rounded down to Centos Linux or FreeBSD. Very good, let’s continue.… Read the rest of this entry »

Some Centos users are complaining about the following error when executing SUDO:

audit_log_user_command(): Connection refused

However, this is nothing to worry about. Centos kernel doesn’t have this feature enabled for audit and this is why it’s complaining. For example, Fedora has compiled this feature into own kernel and no problems are reported. Until a “bug” fix is released feel free to ignore this error message.… Read the rest of this entry »

We have seen great performance on using ReiserFS for mail system spools and in our tests ReiserFS file system spool for Postfix queues was very fast. For best performance we used

notail, noatime mount options in /etc/fstab file.

Full example:

/dev/sda2/usr reiserfs notail,noatime,rw,auto 0 0

notatime – turns off atimes calls, reduces IO and greatly increases file system performance
notail – increases performance of ReiserFS especially for small files – works great for mail servers, web servers and caches. This option disables file pckaging in tree.… Read the rest of this entry »

Lately, we have been testing our server environment and setting up our Linux powered lab where all servers are connected to 1Gbps managed switches.

One of the first tests we had was testing Ethernet cables – CAT 5e and CAT 6 category cables. CAT 6 is the standard for Gigabit Ethernet and backward compatible with CAT 5 and CAT 5e. CAT 6 provides performance of up to 250 Mhz.

In our tests we will review data transfers between two servers each connected to 1Gbps switch. Our maximum data throughput for these boxes are at around 350Mbps due to network card … Read the rest of this entry »

If you are installing Mailscanner and Spamassassin from source or some RPMs it’s been know to use Bayesian statistics engine with it’s database kept forever. This fills up /var/spool/MailScanner/spamassassin folder pretty quickly if you have a moderate load SMTP incoming server. To fix this problem and rebuild Bayesian filters you need to change the following value in /etc/MailScanner/MailScanner.conf file

find the following setting:

Rebuild Bayes Every = 0

and replace it with

Rebuild Bayes Every = 12000

This will rebuild Bayesian spamassassin database/files every 200 minutes. You can of course aim for a higher value if you have enough disk … Read the rest of this entry »

Many folks have been getting the error message sending email using php’s mail() function on Fedora, Red Hat Enterprise and Centos boxes, possible many others.

This error usually happens if you are using Postfix or Sendmail MTA. The error shows up in the maillog file as follows:

postfix/sendmail: fatal: Recipient addresses must be specified on the command line or via the -t option

You can fix this problem by editing sendmail_path value in php.ini file and commenting the following line (possible, making the changes to it as shown below)

sendmail_path = /usr/sbin/sendmail -t

Restart Apache and see if it works. … Read the rest of this entry »