I have a VPS server from LiquidWeb... it feels like sometimes during the day it's laggy. Since it's 100% virtual, I can't just check "top" to gauge the performance since that is measuring within the VPS. (In other words: if I am never running anything on the VPS, top will always show the same memory use and server load of zero, but because the VPS lives on a shared physical box, it may still fluctuate in speed.)
Is there a way to measure the "real" speed of how the VPS is performing? I was thinking about just hacking a little script that runs a loop (doing something-- file actions, or ??) and logs the time, so I could start to build history... but I'd prefer a more reliable/fundamental stat.
Hello I had a similar task and I've done the following(if the server is a windows VPS ) :
If you have an MSSQL instance there be sure to monitor it's performance and CPU \ RAM limits .
If you have IIS be sure to check the logs and if any application has "fatal" errors
For Linux VPS :
Usually, is a good idea use iostat to take measures of the disk access times. Vmstat to see your memory and htop to cpu.
If your running windows use performance monitor.
Usualy in VMs the bottleneck is the disk access latency.
I could give you some idea abut your performance issues.
Define what are the important measures to you, like: IO, CPU, Latecy, ...
Then find an appropriate testprogram, for example testing Disk IO bonnie++ is a good choise, but you can find many more standard test progras in Phoronix Test Suite.
Do more tests on different systems and compare the results.
And also check system statistics with top, iotop, iftop during the tests. As well, if the provider gives you graphs like Amazon does, check them during the tets.