Hello everyone, first, i'm sorry for my very bad english, i'll do my best, i hope you will understand me. I've a question about io disk performance on openvz. I think i'm doing something wrong because I have strange behaviours with io disk and bad performances. I have 2 servers (with exactly the same hardware), one with OpenVZ kernel 2.6.18-12-fza-amd64 (server A), and the other with Vserver kernel 2.6.18-5-vserver-amd64 (server B). The distribution is Debian (same configuration). There are 5 VM on the server A, 5 VM on the server B If I do, for example, a : - du -s /home/dir1" on the server A and - du -s /home/dir1" on the server 2 (it's the same directory = ~20GB) I noticed that the server B with Vserver is twice as much fast as the server A with OpenVZ (it gives me the answer in 3 minutes for example and server B in 6 minutes...). I also noticed that server A had a load average of 6 whereas the server B had just 2~3. I know that it's not a very interesting test, but i've the same feelings with rsync, cp etc... (every operations which consist in io disk...), and with all servers that i've deployed with OpenVZ. That's why i think i'm doing something wrong. Do you think UBC parameters can have an impact on this ? Thank you very much !
I'm assuming your using Debian based on the kernel? We have been having issues with memory leaking on the Debian kernels, more so on the fza-12 version. Even running fza-14 currently we have issues with memory leaks. It is most likely the swapping that is causing I/O issues which was the same with ours. Upgrading the kernel helped but it still has issues.