I simply searched for large (2gb) log files and deleted them. Everything became normal.

There are 2 directives which affect upload limit i.e. upload_max_filesize and post_max_size.

Now we look at the first method. First you have to find out where the php.ini is. To find out the location, make a .php file containing only this code and place it in your webroot and point your browser to this file.

<?php phpinfo(); ?>

In the page output you can find Configuration File Path. Open this file and change the values for upload_max_filesize and post_max_size according to your requirement e.g. to set 10MB upload limit, the values will be
upload_max_filesize = 10M
post_max_size = 10M

After changing the values, save php.ini and restart the webserver. If you open up the above PHP file again, you'll see the updated values of upload_max_filesize and post_max_size.

In case you don't have access to php.ini (in shared hosting environment) or don't want to restart the webserver then the best option is to use .htaccess.

The syntax for .htaccess as follows
php_value upload_max_filesize 10M
php_value post_max_size 10M

Apache supports .htaccess. I am not sure if you can overwrite these settings in .htaccess with lighttpd.

Make a .php file containing only this code

<?php phpinfo(); ?>

And upload this file to your new server and open in the browser. In the page output find the value for 'register_globals'. If it is off, then you can solve this problem in the following ways

1. Turn on the register_globals in php.ini by
   register_globals = On
   (it will not be possible if you are on a shared web server)
2. Put extract($_REQUEST) on the top of every .php file.
3. Turn on register_globals using .htaccess make a text file with the name .htaccess and put the following code in it and upload to the root folder
   php_flag register_globals on
   If you already have a .htaccess file in your website, then simply put this code in it.

You can enable mod_rewrite for Apache 1.3 with the below steps easily.

First step
Remove '#' in front of
LoadModule rewrite_module modules/mod_rewrite.so
Make sure 'mod_rewrite.so' is available under 'apache installation directory/modules'.

Second step
Remove '#' in front of
AddModule mod_rewrite.c

Third step
Set AllowOverride to any of these
AllowOverride FileInfo Options
or
AllowOverride All

Rember, you will find 2 instances of AllowOverride. One like
<Directory />
Options FollowSymLinks
AllowOverride None
</Directory>

and the 2nd one similar to

<Directory "C:/Program Files/Apache Group/Apache/htdocs">
Options Indexes FollowSymLinks MultiViews
AllowOverride None
Order allow,deny
Allow from all
</Directory>

Change the value in the 2nd instance.
Don't forget to restart Apache for these changes to take affect.

A cool mod_rewrite cheat sheet.