Servers

Joomla Media Manager default Upload Limit is 10MB.

This can be changed:

Joomla 1.6 and Joomla 1.7: Content > Media Manager > Options > Maximum Size (in MB)
Joomla 1.5: Global Configuration > System > Maximum Size (in bytes)

If you try to upload file which is too large, you should normally get the following error:
This file is too large to upload.

php.ini can be located in quite few different places depending on your Linux distribution and Apache installation.

Some common places are:
/etc/php.ini
/etc/php/php.ini
/etc/php5/php.ini
/etc/php5/apache2/php.ini
/usr/bin/php5/bin/php.ini

If you still can't find it, run:
find / -name php.ini
This will find all files with name php.ini on your server.

Problem:

All Joomla websites hosted on single virtual server are down.
Trying to access any of the sites, web browsers display following errors:
Infinite loop detected in JError
or
Database Error: Unable to connect to the database:Could not connect to MySQL
phpMyAdmin web interface displays login screen would not allow to login (simply reloads the page after submitting credentials).
Trying to connect to MySQL via console fails with errors:
ERROR 1040 (hy000): Too many connections
or
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

Samba is a free Linux/Unix software which provides file and print access for Microsoft Windows clients. If you have a Linux file server or Linux based NAS device on a network with Windows clients you are probably using Samba.

Samba deals with file locking, preventing file corruption and data loss when two or more clients try to simultaneously edit the same file. There may be situations where you need to force file unlock, for example when file was closed but lock was not properly released by Samba.

Unfortunately Samba doesn't allow unlocking individual files. There are couple of workarounds though.

Increase Joomla Media Manager Upload File Size Limit

Where is php.ini located?

MySQL server down: ERROR 2002 (HY000)

Problem:

Unlock network files locked by Samba Linux / Unix Server