We get a lot of questions about licenses, especially which license is best for a particular customer. I want to take a moment to answer some of the most frequent questions/misunderstandings about LiteSpeed licenses:
(A lot of these issues are actually answered in this wiki: http://www.litespeedtech.com/support/wiki/doku.php?id=litespeed_wiki:license:what_license_to_choose)
1. The VPS license will NOT work on dedicated servers or VPSs with more than 2GB of RAM. And the new Ultra VPS license will not work on a VPS with more than 8GB of RAM. If you try to register one of these licenses on a server with too much memory (or you upgrade your server over the limit), you will get an error message like this:
2013-03-13 09:29:21.669 [NOTICE] Memory size is: 12198100KB. 2013-03-13 09:29:22.042 [NOTICE] [OK] Updated license key has been created at /usr/src/lsws/lsws-4.2.2/license.key. [OK] License key received. 2013-03-13 09:29:22.047 [NOTICE] Memory size is: 12198100KB. [ERROR] VPS license cannot be used on VPS with more than 2GB memory. Please upgrade your license to 1-CPU license! The license key received does not work. [ERROR] Sorry, installation will abort without a valid license key. **ERROR** Failed to install, abort!
The limit on the VPS and Ultra VPS licenses does not mean that the license will just limit the amount of RAM they have access to. They will literally not work. Sorry, but that's how it is.
(You will sometimes get a message like
[NOTICE] Memory size is: 3145728KB
when you are within your memory limits. This is just a notice, not an error.)
2. The 1-CPU, 2-CPU, etc. licenses, however, do simply limit the number of cores LSWS has access to. The number of CPUs in the license name refers to the number of cores the license will be able to use. If you have a server with two quad-core processors (and thus eight cores), you could buy an 8-CPU license to make use of all those cores, but you absolutely, positively do not need to. Instead, you could buy a 1-CPU license, run LSWS on one of the cores, and save all the rest for PHP and MySQL. Many, many of our customers do that (and never regret it).
3. What license should you buy? That's tough… How much power LSWS needs depends on what your particular site does. Remember that LSWS is only part of the equation — your site probably has external application and database processes, too, and these often take much more processing power than LSWS. It's very rare for a user to need LiteSpeed to have access to their your cores. There are some kinds of sites that tax the server software — sites with lots of static content or HTTPS — and these will be helped by more powerful LiteSpeed licenses. Giving LiteSpeed more power (and getting the caching that comes with a 2-CPU license) can help with PHP, too, but many times LSWS is not the bottleneck. In fact, most customers do fine with a license that covers half their cores or less. Try using the top command to see what kinds of processes are running and get an idea of where your bottlenecks are.
The most important thing to remember, though, is that you can upgrade or downgrade at any time. We will only charge you the prorated difference if you upgrade (if you upgrade halfway through the month, you only get charged for the more expensive license for half the month) and we'll credit your account if you downgrade.
If you've got any still-unanswered, burning questions, we'd love to hear them — either here or on the forum. As always, thanks for choosing LiteSpeed!