本教程的目的是引進性能分析師提供的免費工具,來監(jiān)視和管理UNIX系統(tǒng)的性能,以及如何診斷和修復性能問題在Unix環(huán)境提供指引。
UNIX具有以下主要資源類型,需要進行監(jiān)測和調(diào)整:
CPU
內(nèi)存
磁盤空間
通信線路
I/O 時間
網(wǎng)絡時間
應用程序
有以下主要的五個組成部分的系統(tǒng)總時間的推移:
| 組件 | 描述 |
|---|---|
| User state CPU | The actual amount of time the CPU spends running the users program in the user state. It includes time spent executing library calls, but does not include time spent in the kernel on its behalf. |
| System state CPU | This is the amount of time the CPU spends in the system state on behalf of this program. All I/O routines require kernel services. The programmer can affect this value by the use of blocking for I/O transfers. |
| I/O Time and Network Time | These are the amount of time spent moving data and servicing I/O requests |
| Virtual Memory Performance | This includes context switching and swapping. |
| Application Program | Time spent running other programs - when the system is not servicing this application because another application currently has the CPU. |
UNIX提供了重要的工具來測量和微調(diào)Unix系統(tǒng)的性能:
| 命令 | 描述 |
|---|---|
| nice/renice | Run a program with modified scheduling priority |
| netstat | Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships |
| time | Time a simple command or give resource usage |
| uptime | System Load Average |
| ps | Report a snapshot of the current processes. |
| vmstat | Report virtual memory statistics |
| gprof | Display call graph profile data |
| prof | Process Profiling |
| top | Display system tasks |
您可以使用聯(lián)機幫助幫助這里提到的每個命令的語法檢查完成。