- 论坛徽章:
- 0
|
性能问题
内核:
uname -a 2.4.21-20.ELsmp
top :
CPU states: cpu user nice system irq softirq iowait idle
total 8.8% 0.0% 6.0% 0.8% 0.0% 275.6% 107.6%
cpu00 2.6% 0.0% 1.0% 0.0% 0.0% 76.7% 19.6%
cpu01 3.6% 0.0% 3.8% 0.0% 0.0% 61.6% 31.0%
cpu02 1.4% 0.0% 0.8% 1.0% 0.2% 76.6% 20.0%
cpu03 1.4% 0.0% 0.6% 0.0% 0.0% 61.0% 37.0%
free -m
total used free shared buffers cached
Mem: 2007 1989 18 0 6 1450
-/+ buffers/cache: 532 1474
Swap: 1992 404 1588
问题1: 为什么iowait 居高 ? 是硬盘瓶径或是内存问题?
附录: 我的硬盘是scsi 做的raid 1
hdpram -Tt /dev/sda1
/dev/sda1:
Timing buffer-cache reads: 3036 MB in 2.00 seconds = 1518.00 MB/sec
Timing buffered disk reads: 16 MB in 3.15 seconds = 5.08 MB/sec (这值好小啊, 虽然现在系统有点忙)
问题2 : 为什么swap 用的那么多? buffers/cache 明明free 1474 为什么占用这么多swap ,这明显会影响速度啊.
请有经验的朋友帮我分析下.先谢谢了. |
|