Question: My database server is timing out because MySQL seems to hang once it has used up 4GB of RAM, even though the server is equipped with 6GB. How can I make MySQL take advantage of the full 6GB available? Answer: If your current server setup involves a 32-bit architecture …
July, 2010
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2 July
MySQL Optimization: Part 2
1. Query cache – On most servers, there are certain MySQL queries that you and/or your scripts will run more often than others. In fact, you may run the same query hundreds or even thousands of times in a single day. The query_cache setting will save the most used queries …
February, 2010
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12 February
Virtual machine memory allocation
Question: How much memory will I need to run virtual machines on my server? Answer: There is no simple answer to this question. Generally speaking, to virtualize an operating system you need at least as much RAM as is normally required to run the OS independently. Therefore, if your OS …
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8 February
How to set resource limits on PHP
In a previous post, we learned how to increase the memory limit on PHP by editing the php.ini file. But limits exist for a reason, and although you would probably love to give every process, every script, and every website unlimited CPU cycles, memory, and bandwidth, it just isn’t possible. …
January, 2010
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25 January
Identifying memory consumption by process in Linux
Question: How do I find out how memory is used by a particular process in Linux? Answer: On a Linux server, a nifty little command called “pmap” will do just what you want. The command string that you will need to enter as root is: # pmap -d PID But …
December, 2009
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29 December
System monitoring with phpSysInfo
Sometimes you just need quick information about your server without having to click through numerous control panel screens or logging via SSH. A small PHP software application, called phpSysInfo, allows you to do just that. Installed like a normal PHP script, you can access a plethora of information about your …
October, 2009
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15 October
PHP Memory Limit
Question: My PHP content management program “X” needs more RAM. How do I fix this? Answer: Depending on your server setup and whether you have shared hosting or a dedicated server, you may or may not be able to change the allowed PHP memory usage. What happens is that PHP …
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2 October
Understanding Linux RAM Usage
Question: I run Windows on my home computer, and I noticed that my Linux dedicated server is always using a lot of RAM. Why? Answer: Windows and Linux utilize RAM in different ways. Someone new to Linux might be alarmed to see that the amount of free RAM Linux leaves …