Hi team, here's a new guide.
Background
If the host memory is insufficient or the CPU usage is too high,
the host's capability of delivering services is affected.
To solve this problem,
replace the host with a higher performance host or increase the number of hosts for concurrent tests.
The maximum dominant frequency determines the processing capability of a single core.
In the test tool, a worker or thread occupies one CPU core.
When the load is light or the number of concurrent connections is small, the higher the CPU frequency, the faster the server can deliver I/Os, that is, the higher the IOPS capability.
1 Checking the Memory and CPU Usage of a Windows Host
For a Windows host, you can open the performance monitor of the host task manager to check whether the host memory is sufficient and whether the host CPU usage is too high.
In addition, you can view the host and memory usage through the Windows Task Manager.
For example, when a single thread of the IOmeter is used to perform an IOPS test,
if the CPU core usage of the host is high, the performance bottleneck is the host CPU.
2 Checking the Memory and CPU Usage of a Linux Host
For Linux hosts, you can run the top command.
3 Checking the Memory and CPU Usage of the AIX Host
Run the lsattr -El mem0 command to check the memory of the AIX host. The method is as follows:
Run the vmstat command to check the usage of the virtual memory and the actual memory.
page indicates the number of incoming and outgoing pages. If pi po is often a non-zero value, the memory may be insufficient. wa indicates the time for waiting for I/Os. In normal cases, the value is not too high. avm indicates the number of active virtual pages that are allocated to the working segment during process running. The unit is 4 KB. The smaller the number of pages, the better. Note that the avm does not include the file system cache. fre indicates the number of free lists. Generally, the value of fre is greater than or equal to 120. When fre is less than 120, the system automatically kills the process to release the free list.
To check the CPU, perform the following steps:
Run the lsdev -Cc processor command to check the number of CPU cores.
Run the sar [printing frequency][printing times] command to check the CPU usage.
When %usr + %sys > 80%, the CPU is the bottleneck.
Run the ps aux | head -4 command to check the processes that occupy the first three bits of CPU.
%CPU indicates the percentage of CPU time used by a process. %MEM indicates the percentage of the actual memory used by the process.
4 Checking the Memory and CPU Usage of VMware ESXi Hosts
Enter the esxtop command and press Enter.
In this case, the CPU performance statistics (CPU mode, corresponding to the letter C) are displayed.
Enter M to switch to memory performance statistics.
Enter F. The following page is displayed. You can select monitoring items.
Options with an asterisk are monitored.
Enter the letter in front of the option to select the monitoring item, and then enter the letter in front of the option again to cancel the monitoring item. Press Enter to return.
