服务器统计：
“cat /proc/version”输出
Linux version 2.6.18-308.24.1.el5 ([email protected]) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-52)) #1 SMP Tue Dec 4 17:43:34 EST 2012
ethtool eth0 输出：
Settings for eth0:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised auto-negotiation: Yes
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: pumbg
Wake-on: g
Current message level: 0x00000001 (1)
Link detected: yes
cat /proc/cpuinfo | grep MHz 输出：
cpu MHz : 3201.000
cpu MHz : 3201.000
cpu MHz : 3201.000
cpu MHz : 3201.000
cpu MHz : 3201.000
cpu MHz : 3201.000
cpu MHz : 3201.000
cpu MHz : 3201.000
我对 Linux 不是很在行，一直在试图找出这台服务器负载如此之高的原因。我认为要么是硬盘速度不够快，要么是中断太多，因为“ksoftirqd”进程有时会占用大量 CPU，而且似乎运行时间很长。
我一直在互联网上研究如何正确诊断这个问题，我相信我已经找到了如何正确地提供有用的信息，但不幸的是结果仍然让我感到困惑。
顶部输出
top - 08:40:31 up 132 days, 2:06, 2 users, load average: 84.25, 63.29, 63.02
Tasks: 3214 total, 8 running, 3206 sleeping, 0 stopped, 0 zombie
Cpu(s): 18.6%us, 3.2%sy, 0.0%ni, 41.1%id, 26.8%wa, 0.3%hi, 9.9%si, 0.0%st
Mem: 32934596k total, 25811556k used, 7123040k free, 329988k buffers
Swap: 4194296k total, 128k used, 4194168k free, 10888060k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1846 nobody 16 0 125m 12m 4944 S 3.9 0.0 0:00.47 httpd
13490 nobody 15 0 126m 13m 5064 S 2.9 0.0 0:02.37 httpd
20137 everprox 16 0 127m 13m 4908 D 2.6 0.0 0:00.76 httpd
1827 everprox 15 0 127m 13m 4924 S 2.0 0.0 0:00.50 httpd
16574 root 15 0 15120 3480 812 R 2.0 0.0 0:00.15 top
16894 nobody 15 0 126m 84m 944 S 2.0 0.3 946:10.13 nginx
6347 root 16 0 15112 3552 816 S 1.6 0.0 3:16.46 top
7115 named 25 0 422m 52m 2084 S 1.6 0.2 4089:16 named
16575 everprox 16 0 126m 11m 3992 D 1.6 0.0 0:00.05 httpd
16891 nobody 15 0 149m 89m 944 S 1.6 0.3 939:49.39 nginx
16892 nobody 15 0 126m 84m 944 S 1.6 0.3 940:41.47 nginx
26041 everprox 15 0 126m 13m 5076 S 1.6 0.0 0:01.55 httpd
26113 nobody 15 0 126m 13m 5024 S 1.6 0.0 0:02.46 httpd
4345 everprox 15 0 126m 13m 5040 S 1.3 0.0 0:01.82 httpd
13131 everprox 15 0 125m 12m 5072 S 1.3 0.0 0:01.82 httpd
14058 everprox 15 0 127m 13m 5132 D 1.3 0.0 0:01.57 httpd
14554 nobody 15 0 126m 13m 4896 S 1.3 0.0 0:00.74 httpd
26209 everprox 15 0 126m 13m 5044 S 1.3 0.0 0:03.08 httpd
26283 everprox 16 0 125m 12m 5108 D 1.3 0.0 0:02.06 httpd
4360 everprox 15 0 126m 13m 5088 S 1.0 0.0 0:01.93 httpd
12997 everprox 15 0 126m 13m 5052 S 1.0 0.0 0:03.33 httpd
13351 nobody 15 0 127m 13m 5168 S 1.0 0.0 0:02.43 httpd
13705 everprox 15 0 126m 13m 5076 D 1.0 0.0 0:01.55 httpd
13870 nobody 16 0 126m 13m 5088 S 1.0 0.0 0:02.73 httpd
13931 nobody 15 0 126m 13m 5064 S 1.0 0.0 0:02.57 httpd
14008 everprox 15 0 127m 13m 5156 D 1.0 0.0 0:03.39 httpd
14009 everprox 15 0 126m 13m 5064 D 1.0 0.0 0:01.94 httpd
14215 everprox 15 0 126m 13m 5044 S 1.0 0.0 0:01.68 httpd
14550 everprox 16 0 126m 12m 5088 D 1.0 0.0 0:02.73 httpd
14556 nobody 15 0 126m 13m 5096 S 1.0 0.0 0:03.57 httpd
14587 everprox 15 0 126m 12m 5072 S 1.0 0.0 0:03.74 httpd
14625 nobody 15 0 126m 13m 5108 S 1.0 0.0 0:02.93 httpd
14671 everprox 15 0 126m 13m 5048 S 1.0 0.0 0:02.92 httpd
16893 nobody 15 0 125m 81m 944 R 1.0 0.3 936:15.00 nginx
16896 nobody 15 0 127m 87m 944 S 1.0 0.3 939:30.33 nginx
16897 nobody 15 0 122m 84m 944 R 1.0 0.3 939:11.18 nginx
20121 nobody 16 0 125m 11m 4752 S 1.0 0.0 0:00.63 httpd
20122 everprox 16 0 126m 13m 5036 D 1.0 0.0 0:00.60 httpd
25391 everprox 16 0 126m 13m 5108 D 1.0 0.0 0:02.74 httpd
25463 everprox 15 0 126m 13m 5036 D 1.0 0.0 0:02.45 httpd
25514 everprox 16 0 126m 13m 5096 D 1.0 0.0 0:01.03 httpd
26130 everprox 15 0 126m 13m 5048 D 1.0 0.0 0:01.42 httpd
26220 nobody 15 0 126m 13m 5068 S 1.0 0.0 0:03.15 httpd
1833 nobody 16 0 126m 12m 4976 S 0.7 0.0 0:00.40 httpd
4364 everprox 15 0 125m 12m 5020 S 0.7 0.0 0:02.01 httpd
4370 nobody 16 0 126m 13m 5076 S 0.7 0.0 0:02.02 httpd
5499 everprox 15 0 126m 12m 4972 S 0.7 0.0 0:00.54 httpd
5507 everprox 16 0 126m 13m 5004 D 0.7 0.0 0:00.50 httpd
12984 everprox 16 0 127m 13m 5064 D 0.7 0.0 0:01.84 httpd
13004 everprox 15 0 126m 13m 5056 S 0.7 0.0 0:02.81 httpd
13029 everprox 16 0 126m 13m 5048 D 0.7 0.0 0:02.65 httpd
free -mt 输出
root@echo [~]# free -mt
total used free shared buffers cached
Mem: 32162 25219 6943 0 322 10690
-/+ buffers/cache: 14206 17956
Swap: 4095 0 4095
Total: 36258 25219 11039
iostat：
root@echo [~]# iostat
Linux 2.6.18-308.24.1.el5 (echo.uk7.org) 10/17/2013
avg-cpu: %user %nice %system %iowait %steal %idle
26.95 0.08 12.17 3.42 0.00 57.38
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 111.64 19.88 2038.06 226836250 23259888204
sda1 0.00 0.00 0.00 2688 1076
sda2 111.64 19.88 2038.06 226833282 23259887128
dm-0 255.26 19.88 2038.06 226831554 23259887880
dm-1 0.00 0.00 0.00 1160 344
sar -I SUM输出：
Linux 2.6.18-308.24.1.el5 (echo.uk7.org) 10/17/2013
12:00:01 AM INTR intr/s
12:10:01 AM sum 17315.21
12:20:01 AM sum 23640.63
12:30:05 AM sum 26005.42
12:40:05 AM sum 27051.29
12:50:01 AM sum 25887.09
01:00:01 AM sum 25915.91
01:10:02 AM sum 25643.99
01:20:01 AM sum 25590.73
01:30:01 AM sum 25843.38
01:40:01 AM sum 25817.66
01:50:01 AM sum 25937.93
02:00:03 AM sum 25836.42
02:10:01 AM sum 25850.17
02:20:01 AM sum 25788.77
02:30:01 AM sum 25680.55
02:40:01 AM sum 25871.60
02:50:01 AM sum 27089.20
03:00:01 AM sum 26069.86
03:10:01 AM sum 26368.91
03:20:01 AM sum 25977.64
03:30:04 AM sum 26038.12
03:40:05 AM sum 26278.10
03:50:02 AM sum 25988.70
04:00:04 AM sum 26723.36
04:10:05 AM sum 26150.12
04:20:03 AM sum 25904.27
04:30:01 AM sum 26030.90
04:40:09 AM sum 25714.96
04:50:10 AM sum 25732.73
05:00:01 AM sum 24374.81
05:10:01 AM sum 21990.37
05:20:01 AM sum 22917.79
05:30:03 AM sum 22847.98
05:40:03 AM sum 24926.45
05:50:01 AM sum 24986.11
06:00:01 AM sum 24935.01
06:10:04 AM sum 25438.65
06:20:01 AM sum 25430.91
06:30:03 AM sum 26959.88
06:40:01 AM sum 26723.60
06:50:01 AM sum 26422.57
07:00:01 AM sum 26052.94
07:10:07 AM sum 27915.00
07:20:01 AM sum 25868.20
07:30:06 AM sum 25811.18
07:40:05 AM sum 25843.82
07:50:01 AM sum 25814.03
08:00:01 AM sum 25554.51
08:10:01 AM sum 24948.75
08:20:01 AM sum 25413.89
08:30:06 AM sum 25860.78
08:40:01 AM sum 25819.49
Average: sum 25512.26
sar -w 输出：
Linux 2.6.18-308.24.1.el5 (echo.uk7.org) 10/17/2013
12:00:01 AM cswch/s
12:10:01 AM 150959.09
12:20:01 AM 108496.38
12:30:05 AM 32508.30
12:40:05 AM 17555.99
12:50:01 AM 21667.90
01:00:01 AM 89007.13
01:10:02 AM 95902.66
01:20:01 AM 83193.93
01:30:01 AM 76984.23
01:40:01 AM 82111.94
01:50:01 AM 77520.72
02:00:03 AM 39197.94
02:10:01 AM 22047.28
02:20:01 AM 21469.65
02:30:01 AM 26522.87
02:40:01 AM 63104.71
02:50:01 AM 85472.19
03:00:01 AM 40869.59
03:10:01 AM 34278.48
03:20:01 AM 15844.37
03:30:04 AM 16504.44
03:40:05 AM 25177.02
03:50:02 AM 18018.24
04:00:04 AM 27187.20
04:10:05 AM 29010.02
04:20:03 AM 40022.62
04:30:01 AM 69535.67
04:40:09 AM 96043.34
04:50:10 AM 82239.90
05:00:01 AM 128834.10
05:10:01 AM 167916.98
05:20:01 AM 130773.27
05:30:03 AM 125977.75
05:40:03 AM 112561.88
05:50:01 AM 94872.38
06:00:01 AM 98417.10
06:10:04 AM 91611.66
06:20:01 AM 94804.15
06:30:03 AM 75834.69
06:40:01 AM 54488.51
06:50:01 AM 24460.81
07:00:01 AM 16950.60
07:10:07 AM 24471.96
07:20:01 AM 16379.81
07:30:06 AM 15711.76
07:40:05 AM 15708.03
07:50:01 AM 16305.04
08:00:01 AM 18454.64
08:10:01 AM 73621.10
08:20:01 AM 57868.75
08:30:06 AM 15440.36
08:40:01 AM 14954.61
08:50:01 AM 14906.57
Average: 58290.70
sar -d 5 0 输出：
root@echo [~]# sar -d 5 0
Linux 2.6.18-308.24.1.el5 (echo.uk7.org) 10/17/2013
08:52:50 AM DEV tps rd_sec/s wr_sec/s avgrq-sz avgqu-sz await svctm %util
08:52:55 AM dev8-0 104.40 0.00 1760.00 16.86 19.86 190.26 1.64 17.12
08:52:55 AM dev8-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
08:52:55 AM dev8-2 104.40 0.00 1760.00 16.86 19.86 190.26 1.64 17.12
08:52:55 AM dev253-0 220.00 0.00 1760.00 8.00 40.12 182.36 0.78 17.12
08:52:55 AM dev253-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
08:52:55 AM DEV tps rd_sec/s wr_sec/s avgrq-sz avgqu-sz await svctm %util
08:53:00 AM dev8-0 98.40 0.00 1771.20 18.00 17.44 177.22 1.62 15.92
08:53:00 AM dev8-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
08:53:00 AM dev8-2 98.40 0.00 1771.20 18.00 17.44 177.22 1.62 15.92
08:53:00 AM dev253-0 221.40 0.00 1771.20 8.00 36.61 165.36 0.72 15.92
08:53:00 AM dev253-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
08:53:00 AM DEV tps rd_sec/s wr_sec/s avgrq-sz avgqu-sz await svctm %util
08:53:05 AM dev8-0 109.20 0.00 1916.80 17.55 18.26 167.25 1.75 19.14
08:53:05 AM dev8-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
08:53:05 AM dev8-2 109.20 0.00 1916.80 17.55 18.26 167.25 1.75 19.14
08:53:05 AM dev253-0 239.60 0.00 1916.80 8.00 26.30 109.78 0.80 19.14
08:53:05 AM dev253-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
08:53:05 AM DEV tps rd_sec/s wr_sec/s avgrq-sz avgqu-sz await svctm %util
08:53:10 AM dev8-0 104.79 0.00 2000.80 19.09 18.60 177.46 1.68 17.62
08:53:10 AM dev8-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
08:53:10 AM dev8-2 104.79 0.00 2000.80 19.09 18.60 177.46 1.68 17.62
08:53:10 AM dev253-0 250.10 0.00 2000.80 8.00 38.19 152.70 0.70 17.62
08:53:10 AM dev253-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
08:53:10 AM DEV tps rd_sec/s wr_sec/s avgrq-sz avgqu-sz await svctm %util
08:53:15 AM dev8-0 174.35 0.00 3148.70 18.06 21.08 120.73 1.63 28.36
08:53:15 AM dev8-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
08:53:15 AM dev8-2 174.35 0.00 3148.70 18.06 21.08 120.73 1.63 28.36
08:53:15 AM dev253-0 393.59 0.00 3148.70 8.00 39.29 99.81 0.72 28.36
08:53:15 AM dev253-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sar -W 输出：
12:00:01 AM pswpin/s pswpout/s
12:10:01 AM 0.00 0.00
12:20:01 AM 0.00 0.00
12:30:05 AM 0.00 0.00
12:40:05 AM 0.00 0.00
12:50:01 AM 0.00 0.00
01:00:01 AM 0.00 0.00
01:10:02 AM 0.00 0.00
01:20:01 AM 0.00 0.00
01:30:01 AM 0.00 0.00
01:40:01 AM 0.00 0.00
01:50:01 AM 0.00 0.00
02:00:03 AM 0.00 0.00
02:10:01 AM 0.00 0.00
02:20:01 AM 0.00 0.00
02:30:01 AM 0.00 0.00
02:40:01 AM 0.00 0.00
02:50:01 AM 0.00 0.00
03:00:01 AM 0.00 0.00
03:10:01 AM 0.00 0.00
03:20:01 AM 0.00 0.00
03:30:04 AM 0.00 0.00
03:40:05 AM 0.00 0.00
03:50:02 AM 0.00 0.00
04:00:04 AM 0.00 0.00
04:10:05 AM 0.00 0.00
04:20:03 AM 0.00 0.00
04:30:01 AM 0.00 0.00
04:40:09 AM 0.00 0.00
04:50:10 AM 0.00 0.00
05:00:01 AM 0.00 0.00
05:10:01 AM 0.00 0.00
05:20:01 AM 0.00 0.00
05:30:03 AM 0.00 0.00
05:40:03 AM 0.00 0.00
05:50:01 AM 0.00 0.00
06:00:01 AM 0.00 0.00
06:10:04 AM 0.00 0.00
06:20:01 AM 0.00 0.00
06:30:03 AM 0.00 0.00
06:40:01 AM 0.00 0.00
06:50:01 AM 0.00 0.00
07:00:01 AM 0.00 0.00
07:10:07 AM 0.00 0.00
07:20:01 AM 0.00 0.00
07:30:06 AM 0.01 0.00
07:40:05 AM 0.00 0.00
07:50:01 AM 0.00 0.00
08:00:01 AM 0.00 0.00
08:10:01 AM 0.00 0.00
08:20:01 AM 0.00 0.00
08:30:06 AM 0.00 0.00
08:40:01 AM 0.00 0.00
08:50:01 AM 0.00 0.00
Average: 0.00 0.00
只是想知道是否有什么东西真正引起了比我更了解的人的注意，就像我上面说的，我认为它是一个速度很慢的 HDD，可能 SSD 会做得更好或者中断太多。
该服务器主要是托管基于 Web 的代理的 Web 托管服务器。它运行带有 mod_ruid2 和 nginxcp (cpanel 插件) 的 Apache 2.2.23。
谢谢。
答案1
在我看来，您受到 I/O 限制。从top，您会看到许多带有标志的任务D。这意味着它们在 I/O 上被阻止，等待磁盘的响应。“平均负载”基本上意味着“在 x 时间内等待 x 个任务”。
如果它们都是 Apache，那么您还会有大量（可能太多）工作线程。请考虑稍微调整一下您的服务器或购买更快的硬件。