First, we create a user named mysql_optimizer (with a strong password) and give it select and insert priveleges on the databases. You do not want your root user to be used in a cronjob!

mysql> GRANT SELECT, INSERT ON *.* TO ‘mysql_optimizer’@'localhost’ identified by ‘strong password’;
mysql> flush privileges;
mysql> exit;

Second thing is setting up the crontab, this time a weekly simple schedule:

> crontab -e
# MySQL weekly optimisation
0 0 * * 0 /usr/bin/mysqlcheck -Aos --optimize -u mysql_optimizer -pstrongpassword > /dev/null 2>&1

That’s it!

use utf8;
Win32::OLE->Option( CP => Win32::OLE::CP_UTF8 );

This will tell Perl to use utf-8 encoding in your file and will make sure your strings are correctly piped to the database.
 

iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
iptables -A FORWARD -i eth0 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A FORWARD -i eth1 -o eth0 --source 192.168.0.1 -j ACCEPT
iptables -A FORWARD -i eth1 -o eth0 -j REJECT

Here we will provide internet access to the host 192.168.0.1 behind eth1 over our own internet connection on eth0.
The ip of eth0 can be dynamic. The host 192.168.0.1 will be using the ip of eth0 on the internet.

We only accept traffic from the ip 192.168.0.1, the rest is rejected.

Oh, and don’t forget to enable ipv4 forwarding in the kernel!
Add:

net.ipv4.ip_forward = 1

to /etc/sysctl.conf and run:

sysctl -p /etc/sysctl.conf

Or just run:

echo 1 > /proc/sys/net/ipv4/ip_forward

Your Milage May Vary…

The sorting can easily be done by the following command:

sort -t ' ' -k 4.9,4.12n -k 4.5,4.7M -k 4.2,4.3n -k 4.14,4.15n -k 4.17,4.18n -k 4.20,4.21n access_log.1 > access_log.1.sorted

Adjust, change and implement to match your own personal preference!

Normaly you should always have backups of your databases, restoring suspected databases is not a good option, but I think at some point in time, in some situation you’ll want to do it anyway.
So today I set up a test case for this. I mirrored one of our database servers and made it crash, badly.
Two databases were corrupted, and went to the "suspect state".

Microsoft SQL Server started throwing errors in our general direction like:

"Database cannot be opened. It has been marked SUSPECT by recovery."

Not good, but just what we wanted…

So how would it be possible to recover these databases?

First, set them to emergency mode, this way you will be able to retrieve control.
In emergency mode you can actually open the database:

alter database "test-database" set emergency;

Second, put them in single mode (needed for the check we will be performing):

alter database "test-database" set single_user;

Then, check the database (this repair allows data-loss, since I’m sure some data will have to be lost in my scenario):

dbcc checkdb ('test-database', REPAIR_ALLOW_DATA_LOSS);

Finally, if the check succeeded, you can re-enter multi-mode:

alter database "test-database" set multi_user;

And there you go, the database is restored…
Not a best practice, but it may save some time once. So if you ever have a problem on your dedicated server database hosting, you know this might to the trick.

If you want to configure a serial console on your Dell PowerEdge R410 (or R710) dedicated server with CentOS 5.4 (or 5.3 and probably also the Red Hat Enterprise systems) you can use these guidelines.
In the Bios:

Under "Serial Communication":
Serial Communication: On with Console Redirection via COM1
Serial Port Address: Serial Device1=COM2,Serial Device2=COM1
External Serial Connector: Serial Device2
Failsafe Baud Rate: 115200
Remote Terminal Type: VT100/VT220
Redirection After Boot: Enabled (so grub displays)

Then you configure Grub:

title CentOS (2.6.18-164.6.1.el5) Serial
root (hd0,0)
kernel /vmlinuz-2.6.18-164.6.1.el5 ro root=LABEL=/ console=tty0 console=ttyS0,115200n8
initrd /initrd-2.6.18-164.6.1.el5.img

This makes the kernel display it’s messages on screen and over the serial console.

In /etc/securetty append:

ttyS0
ttyS1

This way root can log in using the serial console.

Finally configure the inittab (/etc/inittab) and add the following line:

co:2345:respawn:/sbin/agetty ttyS0 115200 linux

Now reboot and enjoy pure serial console goodness over ip (ipmi).

(Oh, don’t forget to enable IPMI over lan in the iDrac configuration and to set a username, password and ip-address.
The iDrac 6 configuration flashes by when the server boots.)

Server Error in '/_layouts' Application.

IIS is kind enough to hide all the information about the error, so there you are, without a clue.
Maybe this can solved in the "SharePoint Central Administration"? No luck either, now it throws a similar error.
So, to resolve this issue, we first need to activate the error output in the web.config.
This is located at the following location:

C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\60\template\admin\1033\web.config

Open the file using your favourite text editor and search for the line which sets the customErrors (line 3), change it to:

<customErrors mode="RemoteOnly" />

Now you’ll be able to view the errors when browsing to your Sharepoint installation from the server itself.
This time it presents you the real problem:

Parser Error Message: Could not load file or assembly 'System.EnterpriseServices, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.

Assembly Load Trace: The following information can be helpful to determine why the assembly 'System.EnterpriseServices, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' could not be loaded.

So, how do we fix this missing assembly?
Open two windows explorer screens with these locations:

C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727
C:\WINDOWS\assembly

(The .NET Framework version and Windows Path may differ depending on your installation.)

Then drag the file "System.EnterpriseServices.dll" from the Microsoft.NET\Framework\v2.0.50727 folder to the assembly folder.

Now the problem should be fixed. (It is possible you’ll have to recycle the Application Pool.)
Reload your browser windows, both the Central Administration page at port 9503 en the normal sharepoint pages at port 80 should work.

Thanks goes out to the people at forums.asp.net!

yum clean all

Most likely yum is using some old cached information.

We encountered this problem when upgrading from CentOS 5.0 to 5.3.

We suggest drupal hosting customers to opt for a virtual server setup. Does this mean you can’t host drupal on a shared hosting platform? Not at all, but if you have a high load website, a isolated server instance might give you some advantages.This means you can set up a nice isolated environment for a Drupal driven CMS website with dedicated server performance at severe reduced cost.

When setting up the environment be sure to run through the following checklist:

• CentOS 5.3 (for example)
• Apache 2.2 webserver
• MySQL 5+ database server
• PHP 5+
• and, very important: eAccelerator 9.5.3 or higher.

Why the eAccelerator? Well, Drupal uses a lot of cached pages. Enabling Drupal caching already gives you a boost but installing eAccelerator makes sure frequently used php scripts are stored in a compiled state thus allow retrieval faster.

On top of that, you may optimize the MySQL query_caching settings, as they Drupal also uses a lot of the same queries.

You can find the latest version of eAccelerator here: http://eaccelerator.net/

However, after having migrated a Windows server, we observed that the attributes of folders on the filesystem had been modified.  In Windows Explorer, everything seemed all right, but when FTP’ing to certain folders, or when viewing them with the ‘dir’ command, the folder were hidden.  It appeared that the ‘system’ attribute had been set throughout the C drive.

We solved the problem by executing

attrib /S /D -S -H -R