| VDS with Debian 5 performs much worse than with Debian 3. [message #38711] |
Mon, 18 January 2010 20:51  |
tryl
Messages: 4
Registered: January 2010
Location: Denmark
|
Junior Member |
|
|
I'm transfering my sites to a VDS running Debian 5 from a Debian 3 VDS. When the site with the most load was transfered, the new server started to response very slow, where it performed very well on the old server.
The wird thing is, that in this period the CPU (acording to top) was running at 90%-95% idle, with peaks of 85% idle. Disc-wise I could very fast grep through a folder with a lot of files and dd an about 200 MiB file to /dev/null with about 40 MiB/s. At the same time, there were 120 MiB of memory free. Apache would take about respond 10 sec to respond to any request to a dynamic generated webpage (PHP or ssi) and the same for the first serve of small static files (e.g. robots.txt). On subsequent serves, these small static files would be lightning fast. There is no significant swap and load average is never above 0.20. On the old server, the apache processes would acoring to top (the RES column) rarely consume more than 10 MB of memory, where the new ones easily takes 20 MB and some times more. That is with the same memory settings in apache2.conf and php.ini.
From this I conclude:
The problem is not CPU overload.
The problem is not lack of memory.
The problem is not slow disk access.
The problem is not lack of free httpd processes.
I.e. the problem does not exist and I have absolutely no clue why the new server starts to slow down.
The script which runs the most loaded site, is from zipstat.org and can be browsed at http://zipstat.cvs.sourceforge.net/viewvc/zipstat/zipstat/ (start looking at zipstat.php in the root) and is developed by myself.
The old server runs PHP Version 4.3.10-19 with MySQL 4.0.24 and Apache 2.0 on a Debian 3.1 VDS with kernel 2.6.18-028stab066.11.
The new server runs PHP Version 5.2.6-1+lenny3 with the Suhosin Patch 0.9.6.2, MySQL 5.0.51a and Apache 2.0 on a Debian 5 VDS with kernel 2.6.18-028stab066.11 (yep, the same).
I hope somebody can help or give me a pointer (!= 0) in a right direction. And please, just ask for more info or for me to run tests.
Best regards,
Simon Mikkelsen, Denmark
|
|
|
|
OpenVZ Forum
Members
Search
Help
Register
Login
Home
