有关磁盘空间的命令
mount
概要： 挂载文件系统，mount卸载挂载的文件系统
语法格式： mount [参数] [设备] [目录]
参数：
| 参数 | 概述 |
|---|---|
| -a | 挂载/etc/fstab里面的所有文件系统 |
| -l | 显示已挂载的文件系统列表 |
| -r | 将文件系统挂载为只读模式 |
| -t | 指定文件系统类型 |
| -V | 显示软件版本 |
使用示例：
- 挂载当前系统的光驱到/mnt目录下
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> |
<span class="line">[root@ansheng ~]<span class="comment"># ls /mnt/</span></span> <span class="line">[root@ansheng ~]<span class="comment"># mount /dev/sr0 /mnt/</span></span> <span class="line">mount: block device /dev/sr0 is write-protected, mounting <span class="built_in">read</span>-only</span> <span class="line">[root@ansheng ~]<span class="comment"># ls /mnt</span></span> <span class="line">CentOS_BuildTag isolinux RPM-GPG-KEY-CentOS-Debug-6</span> <span class="line">EFI Packages RPM-GPG-KEY-CentOS-Security-6</span> <span class="line">EULA RELEASE-NOTES-en-US.html RPM-GPG-KEY-CentOS-Testing-6</span> <span class="line">GPL repodata TRANS.TBL</span> <span class="line">images RPM-GPG-KEY-CentOS-6</span> |
umount
概要： 卸载以及挂载的文件系统
语法格式： umount 设备
使用示例：
- 取消以及挂载的文件系统/dev/sda1
<span class="line">1</span>
<span class="line">2</span>
<span class="line">3</span>
<span class="line">4</span>
<span class="line">5</span>
<span class="line">6</span>
<span class="line">7</span>
<span class="line">8</span>
<span class="line">9</span>
10
|
<span class="line">[root@ansheng ~]<span class="comment"># df -h</span></span> <span class="line">Filesystem Size Used Avail Use% Mounted on</span> <span class="line">/dev/sda3 19G 1.5G 17G 8% /</span> <span class="line">tmpfs 491M 0 491M 0% /dev/shm</span> <span class="line">/dev/sda1 190M 27M 153M 16% /boot</span> <span class="line">[root@ansheng ~]<span class="comment"># umount /dev/sda1</span></span> <span class="line">[root@ansheng ~]<span class="comment"># df -h</span></span> <span class="line">Filesystem Size Used Avail Use% Mounted on</span> <span class="line">/dev/sda3 19G 1.5G 17G 8% /</span> <span class="line">tmpfs 491M 0 491M 0% /dev/shm</span> |
df
概要： 查看文件系统磁盘使用情况
语法格式： df [参数]
参数：
| 参数 | 概述 |
|---|---|
| -a | 显示所有文件系统信息 |
| -h | 以M为单位显示 |
| -i | 显示Inode节点号 |
使用示例：
- 显示当前文件系统使用信息，以M为单位显示，并且显示Inode节点
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> |
<span class="line">[root@ansheng /]<span class="comment"># df -hi</span></span> <span class="line">Filesystem Inodes IUsed IFree IUse% Mounted on</span> <span class="line">/dev/sda3 1.3M 56K 1.2M 5% /</span> <span class="line">tmpfs 123K 1 123K 1% /dev/shm</span> <span class="line">/dev/sda1 50K 38 50K 1% /boot</span> |
du
概要： 统计目录（或文件）所占磁盘空间的大小
语法格式： du [参数]
参数：
| 参数 | 概述 |
|---|---|
| -h | 显示单位 |
| -m | 以M为单位显示 |
使用示例：
- 显示当前目录磁盘使用情况
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> |
<span class="line">[root@ansheng boot]<span class="comment"># pwd</span></span> <span class="line">/boot</span> <span class="line">[root@ansheng boot]<span class="comment"># du -h</span></span> <span class="line">251K ./efi/EFI/redhat</span> <span class="line">253K ./efi/EFI</span> <span class="line">255K ./efi</span> <span class="line">276K ./grub</span> <span class="line">13K ./lost+found</span> <span class="line">26M .</span> |
fdisk
概要： fdisk命令用于观察硬盘实体使用情况，也可对硬盘分区。
语法格式： fdisk [选项] [参数]
参数：
| 参数 | 说明 |
|---|---|
| -b<分区大小> | 指定每个分区的大小 |
| -l | 列出指定的外围设备的分区表状况 |
| -u | 搭配”-l”参数列表，会用分区数目取代柱面数目，来表示每个分区的起始地址 |
使用示例：
- 查看当前系统分区信息
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> 10 11 12 13 14 15 |
<span class="line">[root@ansheng ~]<span class="comment"># fdisk -l</span></span> <span class="line">Disk /dev/sda: 21.5 GB, 21474836480 bytes</span> <span class="line">255 heads, 63 sectors/track, 2610 cylinders</span> <span class="line">Units = cylinders of 16065 * 512 = 8225280 bytes</span> <span class="line">Sector size (logical/physical): 512 bytes / 512 bytes</span> <span class="line">I/O size (minimum/optimal): 512 bytes / 512 bytes</span> <span class="line">Disk identifier: 0x0004743c</span> <span class="line"> Device Boot Start End Blocks Id System</span> <span class="line">/dev/sda1 * 1 26 204800 83 Linux</span> <span class="line">Partition 1 does not end on cylinder boundary.</span> <span class="line">/dev/sda2 26 157 1048576 82 Linux swap / Solaris</span> <span class="line">Partition 2 does not end on cylinder boundary.</span> <span class="line">/dev/sda3 157 2611 19717120 83 Linux</span> |
dd
概要： dd命令用于复制文件并对原文件的内容进行转换和格式化处理。
语法格式： dd [OPERAND]… dd OPTION
参数：
| 参数 | 说明 |
|---|---|
| bs=<字节数> | 将ibs（输入）与欧巴桑（输出）设成指定的字节数 |
| cbs=<字节数> | 转换时，每次只转换指定的字节数 |
| conv=<关键字> | 指定文件转换的方式 |
| count=<区块数> | 仅读取指定的区块数 |
| ibs=<字节数> | 每次读取的字节数 |
| obs=<字节数> | 每次输出的字节数 |
| of=<文件> | 输出到文件 |
| seek=<区块数> | 一开始输出时，跳过指定的区块数 |
| skip=<区块数> | 一开始读取时，跳过指定的区块数 |
使用示例：
- 创建一个大小为1G的sun.txt文件
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> |
<span class="line">[root@ansheng ~]<span class="comment"># dd if=/dev/zero of=sun.txt bs=1G count=1</span></span> <span class="line">1+0 records <span class="keyword">in</span></span> <span class="line">1+0 records out</span> <span class="line">1073741824 bytes (1.1 GB) copied, 8.83111 s, 122 MB/s</span> |
if代表输入文件。如果不指定if，默认就会从stdin中读取输入of代表输出文件。如果不指定of，默认就会将stdout作为默认输出bs代表字节为单位的块大小count代表被复制的块数。/dev/zero是一个字符设备，会不断返回0值字节（\0）
查看系统信息
free
概要： 查看内存使用状态
语法格式： free [参数]
参数：
| 参数 | 概述 |
|---|---|
| -m | 以MB为单位显示 |
使用示例：
- 显示当前内存使用信息
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> |
<span class="line">[root@ansheng ~]<span class="comment"># free -m</span></span> <span class="line"> total used free shared buffers cached</span> <span class="line">Mem: 980 167 813 0 28 43</span> <span class="line">-/+ buffers/cache: 95 885</span> <span class="line">Swap: 511 0 511</span> |
vmstat
概要： 用来显示虚拟内存的信息，对操作系统的虚拟内存、进程、CPU活动进行监控。
语法格式： vmstat [-a] [-n] [-S unit] [delay [ count]] vmstat [-s] [-n] [-S unit] vmstat [-m] [-n] [delay [ count]] vmstat [-d] [-n] [delay [ count]] vmstat [-p disk partition] [-n] [delay [ count]] vmstat [-f] vmstat [-V]
参数：
| 参数 | 说明 |
|---|---|
| -a | 显示活跃和非活跃内存 |
| -f | 显示从系统启动至今的fork数量 |
| -m | 显示slabinfo |
| -n | 只在开始时显示一次各字段名称 |
| -s | 显示内存相关统计信息及多种系统活动数量 |
| delay | 刷新时间间隔。如果不指定，只显示一条结果 |
| count | 刷新次数。如果不指定刷新次数，但指定了刷新时间间隔，这时刷新次数为无穷 |
| -d | 显示磁盘相关统计信息 |
| -p | 显示指定磁盘分区统计信息 |
| -S | 使用指定单位显示。参数有 k 、K 、m 、M ，分别代表1000、1024、1000000、1048576字节（byte）。默认单位为K（1024 bytes） |
使用示例：
- 显示虚拟内存使用情况
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> |
<span class="line">[root@ansheng ~]<span class="comment"># vmstat 5 6</span></span> <span class="line">procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu-----</span> <span class="line"> r b swpd free buff cache si so bi bo <span class="keyword">in</span> cs us sy id wa st</span> <span class="line"> 0 0 0 1797468 11652 29852 0 0 20 1 12 14 0 0 100 0 0</span> <span class="line"> 0 0 0 1797420 11652 29880 0 0 0 0 10 11 0 0 100 0 0</span> <span class="line"> 1 0 0 1797420 11652 29880 0 0 0 0 7 9 0 0 100 0 0</span> <span class="line"> 0 0 0 1797420 11652 29880 0 0 0 0 7 10 0 0 100 0 0</span> <span class="line"> 0 0 0 1797420 11652 29880 0 0 0 0 8 10 0 0 100 0 0</span> <span class="line"> 0 0 0 1797420 11652 29880 0 0 0 0 6 10 0 0 100 0 0</span> |
字段说明：
Procs（进程）
| 字段 | 说明 |
|---|---|
| r | 运行队列中进程数量 |
| b | 等待IO的进程数量 |
Memory（内存）
| 字段 | 说明 |
|---|---|
| swpd | 使用虚拟内存大小 |
| free | 可用内存大小 |
| buff | 用作缓冲的内存大小 |
| cache | 用作缓存的内存大小 |
Swap
| 字段 | 说明 |
|---|---|
| si | 每秒从交换区写到内存的大小 |
| so | 每秒写入交换区的内存大小 |
| IO | 现在的Linux版本块的大小为1024bytes |
| bi | 每秒读取的块数 |
| bo | 每秒写入的块数 |
系统
| 字段 | 说明 |
|---|---|
| in | 每秒中断数，包括时钟中断 |
| cs | 每秒上下文切换数 |
CPU（以百分比表示）
| 字段 | 说明 |
|---|---|
| us | 用户进程执行时间(user time) |
| sy | 系统进程执行时间(system time) |
| id | 空闲时间(包括IO等待时间),中央处理器的空闲时间 。以百分比表示 |
| wa | 等待IO时间 |
- 查看内存使用的详细信息
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 |
<span class="line">[root@ansheng ~]<span class="comment"># vmstat -s</span></span> <span class="line"> 1906904 total memory</span> <span class="line"> 109452 used memory</span> <span class="line"> 16112 active memory</span> <span class="line"> 30372 inactive memory</span> <span class="line"> 1797452 free memory</span> <span class="line"> 11660 buffer memory</span> <span class="line"> 29884 swap cache</span> <span class="line"> 1048572 total swap</span> <span class="line"> 0 used swap</span> <span class="line"> 1048572 free swap</span> <span class="line"> 79 non-nice user cpu ticks</span> <span class="line"> 0 nice user cpu ticks</span> <span class="line"> 475 system cpu ticks</span> <span class="line"> 302272 idle cpu ticks</span> <span class="line"> 70 IO-wait cpu ticks</span> <span class="line"> 1 IRQ cpu ticks</span> <span class="line"> 3 softirq cpu ticks</span> <span class="line"> 0 stolen cpu ticks</span> <span class="line"> 46598 pages paged <span class="keyword">in</span></span> <span class="line"> 1549 pages paged out</span> <span class="line"> 0 pages swapped <span class="keyword">in</span></span> <span class="line"> 0 pages swapped out</span> <span class="line"> 29862 interrupts</span> <span class="line"> 35402 CPU context switches</span> <span class="line"> 1461585872 boot time</span> <span class="line"> 1161 forks</span> |
- 查看磁盘的读/写
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<span class="line">[root@ansheng ~]<span class="comment"># vmstat -d</span></span> <span class="line">disk- ------------reads------------ ------------writes----------- -----IO------</span> <span class="line"> total merged sectors ms total merged sectors ms cur sec</span> <span class="line">ram0 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram1 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram2 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram3 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram4 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram5 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram6 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram7 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram8 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram9 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram10 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram11 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram12 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram13 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram14 0 0 0 0 0 0 0 0 0 0</span> <span class="line">ram15 0 0 0 0 0 0 0 0 0 0</span> <span class="line">loop0 0 0 0 0 0 0 0 0 0 0</span> <span class="line">loop1 0 0 0 0 0 0 0 0 0 0</span> <span class="line">loop2 0 0 0 0 0 0 0 0 0 0</span> <span class="line">loop3 0 0 0 0 0 0 0 0 0 0</span> <span class="line">loop4 0 0 0 0 0 0 0 0 0 0</span> <span class="line">loop5 0 0 0 0 0 0 0 0 0 0</span> <span class="line">loop6 0 0 0 0 0 0 0 0 0 0</span> <span class="line">loop7 0 0 0 0 0 0 0 0 0 0</span> <span class="line">sda 2412 2339 90132 1414 207 200 3250 429 0 1</span> |
这些信息主要来自于/proc/diskstats
- 查看/dev/sda1磁盘的读/写
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> 6 7 8 |
<span class="line">[root@ansheng ~]<span class="comment"># df</span></span> <span class="line">Filesystem 1K-blocks Used Available Use% Mounted on</span> <span class="line">/dev/sda3 19276064 3710860 14579348 21% /</span> <span class="line">tmpfs 953452 0 953452 0% /dev/shm</span> <span class="line">/dev/sda1 194241 74429 109572 41% /boot</span> <span class="line">[root@ansheng ~]<span class="comment"># vmstat -p /dev/sda1</span></span> <span class="line">sda1 reads <span class="built_in">read</span> sectors writes requested writes</span> <span class="line"> 497 3986 3 18</span> |
说明：
这些信息主要来自于/proc/diskstats。
| 参数 | 说明 |
|---|---|
| reads | 来自于这个分区的读的次数 |
| read sectors | 来自于这个分区的读扇区的次数 |
| writes | 来自于这个分区的写的次数 |
| requested writes | 来自于这个分区的写请求次数 |
mpstat
概要： mpstat是MultiProcessor Statistics的缩写，是实时系统监控工具,其报告与CPU的一些统计信息，这些信息存放在/proc/stat文件中。
语法格式： mpstat [-P {|ALL}] [internal [count]]
参数：
|参数|说明| |-P {|ALL}|表示监控哪个CPU， cpu在[0,cpu个数-1]中取值| |internal|相邻的两次采样的间隔时间| |count|采样的次数，count只能和delay一起使用|
使用示例：
- 查看多核CPU核心的当前运行状况信息， 每2秒更新一次
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> 10 11 12 13 14 15 16 17 18 19 20 21 22 23 |
<span class="line">[root@ansheng ~]<span class="comment"># mpstat -P ALL 2</span></span> <span class="line">Linux 2.6.32-573.22.1.el6.x86_64 (ansheng) 04/25/2016 _x86_64_ (2 CPU)</span> <span class="line">08:41:21 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle</span> <span class="line">08:41:23 PM all 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00</span> <span class="line">08:41:23 PM 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00</span> <span class="line">08:41:23 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00</span> <span class="line">08:41:23 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle</span> <span class="line">08:41:25 PM all 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00</span> <span class="line">08:41:25 PM 0 0.00 0.00 0.50 0.00 0.00 0.00 0.00 0.00 99.50</span> <span class="line">08:41:25 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00</span> <span class="line">08:41:25 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle</span> <span class="line">08:41:27 PM all 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00</span> <span class="line">08:41:27 PM 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00</span> <span class="line">08:41:27 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00</span> <span class="line">08:41:27 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle</span> <span class="line">08:41:29 PM all 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00</span> <span class="line">08:41:29 PM 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00</span> <span class="line">08:41:29 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00</span> <span class="line">......</span> |
字段含义
| 字段 | 说明 | |
|---|---|---|
| %user | 在internal时间段里，用户态的CPU时间(%)，不包含nice值为负进程 (usr/total)*100 | |
| %nice | 在internal时间段里，nice值为负进程的CPU时间(%) (nice/total)*100 | |
| %sys | 在internal时间段里，内核时间(%) (system/total)*100 | |
| %iowait | 在internal时间段里，硬盘IO等待时间(%) (iowait/total)*100 | |
| %irq | 在internal时间段里，硬中断时间(%) (irq/total)*100 | |
| %soft | 在internal时间段里，软中断时间(%) (softirq/total)*100 | |
| %idle | 在internal时间段里，CPU除去等待磁盘IO操作外的因为任何原因而空闲的时间闲置时间(%) (idle/total)*100 |
iostat
概要： 通过iostat方便查看CPU、网卡、tty设备、磁盘、CD-ROM 等等设备的活动情况, 负载信息。
语法格式： iostat[参数][时间][次数]
参数：
| 参数 | 说明 | |
|---|---|---|
| -C | 显示CPU使用情况 | |
| -d | 显示磁盘使用情况 | |
| -k | 以 KB 为单位显示 | |
| -m | 以 M 为单位显示 | |
| -N | 显示磁盘阵列(LVM) 信息 | |
| -n | 显示NFS 使用情况 | |
| -p[磁盘] | 显示磁盘和分区的情况 | |
| -t | 显示终端和CPU的信息 | |
| -x | 显示详细信息 | |
| -V | 显示版本信息 |
使用示例：
- 显示所有设备负载情况
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> 6 7 8 |
<span class="line">[root@ansheng ~]<span class="comment"># iostat</span></span> <span class="line">Linux 2.6.32-573.22.1.el6.x86_64 (ansheng) 04/25/2016 _x86_64_ (2 CPU)</span> <span class="line">avg-cpu: %user %nice %system %iowait %steal %idle</span> <span class="line"> 0.02 0.00 0.11 0.02 0.00 99.85</span> <span class="line">Device: tps Blk_<span class="built_in">read</span>/s Blk_wrtn/s Blk_<span class="built_in">read</span> Blk_wrtn</span> <span class="line">sda 1.12 37.87 1.56 90588 3738</span> |
属性值说明
cpu属性值说明
| 值 | 说明 | |
|---|---|---|
| %user | CPU处在用户模式下的时间百分比 | |
| %nice | CPU处在带NICE值的用户模式下的时间百分比 | |
| %system | CPU处在系统模式下的时间百分比 | |
| %iowait | CPU等待输入输出完成时间的百分比 | |
| %steal | 管理程序维护另一个虚拟处理器时，虚拟CPU的无意识等待时间百分比 | |
| %idle | CPU空闲时间百分比 |
备注：如果%iowait的值过高，表示硬盘存在I/O瓶颈，%idle值高，表示CPU较空闲，如果%idle值高但系统响应慢时，有可能是CPU等待分配内存，此时应加大内存容量。%idle值如果持续低于10，那么系统的CPU处理能力相对较低，表明系统中最需要解决的资源是CPU。
disk属性值说明：
| 值 | 说明 |
|---|---|
| rrqm/s | 每秒进行 merge 的读操作数目。即 rmerge/s |
| wrqm/s | 每秒进行 merge 的写操作数目。即 wmerge/s |
| r/s | 每秒完成的读 I/O 设备次数。即 rio/s |
| w/s | 每秒完成的写 I/O 设备次数。即 wio/s |
| rsec/s | 每秒读扇区数。即 rsect/s |
| wsec/s | 每秒写扇区数。即 wsect/s |
| rkB/s | 每秒读K字节数。是 rsect/s 的一半，因为每扇区大小为512字节 |
| wkB/s | 每秒写K字节数。是 wsect/s 的一半 |
| avgrq-sz | 平均每次设备I/O操作的数据大小 (扇区) |
| avgqu-sz | 平均I/O队列长度 |
| await | 平均每次设备I/O操作的等待时间 (毫秒) |
| svctm | 平均每次设备I/O操作的服务时间 (毫秒) |
| %util | 一秒中有百分之多少的时间用于 I/O 操作，即被io消耗的cpu百分比 |
备注：如果 %util 接近 100%，说明产生的I/O请求太多，I/O系统已经满负荷，该磁盘可能存在瓶颈。如果 svctm 比较接近 await，说明 I/O 几乎没有等待时间；如果 await 远大于 svctm，说明I/O 队列太长，io响应太慢，则需要进行必要优化。如果avgqu-sz比较大，也表示有当量io在等待。
- 定时显示所有信息
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> 10 11 12 13 14 15 16 17 18 19 20 |
<span class="line">[root@ansheng ~]<span class="comment"># iostat 2 3</span></span> <span class="line">Linux 2.6.32-573.22.1.el6.x86_64 (ansheng) 04/25/2016 _x86_64_ (2 CPU)</span> <span class="line">avg-cpu: %user %nice %system %iowait %steal %idle</span> <span class="line"> 0.02 0.00 0.11 0.01 0.00 99.86</span> <span class="line">Device: tps Blk_<span class="built_in">read</span>/s Blk_wrtn/s Blk_<span class="built_in">read</span> Blk_wrtn</span> <span class="line">sda 1.10 37.41 1.56 90604 3770</span> <span class="line">avg-cpu: %user %nice %system %iowait %steal %idle</span> <span class="line"> 0.00 0.00 0.00 0.00 0.00 100.00</span> <span class="line">Device: tps Blk_<span class="built_in">read</span>/s Blk_wrtn/s Blk_<span class="built_in">read</span> Blk_wrtn</span> <span class="line">sda 0.00 0.00 0.00 0 0</span> <span class="line">avg-cpu: %user %nice %system %iowait %steal %idle</span> <span class="line"> 0.00 0.00 0.25 0.00 0.00 99.75</span> <span class="line">Device: tps Blk_<span class="built_in">read</span>/s Blk_wrtn/s Blk_<span class="built_in">read</span> Blk_wrtn</span> <span class="line">sda 0.00 0.00 0.00 0 0</span> |
每隔 2秒刷新显示，且显示3次
- 显示指定磁盘信息
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> |
<span class="line">[root@ansheng ~]<span class="comment"># iostat -d sda1</span></span> <span class="line">Linux 2.6.32-573.22.1.el6.x86_64 (ansheng) 04/25/2016 _x86_64_ (2 CPU)</span> <span class="line">Device: tps Blk_<span class="built_in">read</span>/s Blk_wrtn/s Blk_<span class="built_in">read</span> Blk_wrtn</span> <span class="line">sda1 0.20 1.62 0.01 3986 18</span> |
- 以M为单位显示所有信息
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> 6 7 8 |
<span class="line">[root@ansheng ~]<span class="comment"># iostat -m</span></span> <span class="line">Linux 2.6.32-573.22.1.el6.x86_64 (ansheng) 04/25/2016 _x86_64_ (2 CPU)</span> <span class="line">avg-cpu: %user %nice %system %iowait %steal %idle</span> <span class="line"> 0.02 0.00 0.11 0.01 0.00 99.86</span> <span class="line">Device: tps MB_<span class="built_in">read</span>/s MB_wrtn/s MB_<span class="built_in">read</span> MB_wrtn</span> <span class="line">sda 1.08 0.02 0.00 44 1</span> |
sar
概要： 系统活动情况报告
语法格式： sar [options] [-A] [-o file] t [n]
参数：
| 参数 | 概述 |
|---|---|
| -A | 所有报告的总和 |
| -u | 输出CPU使用情况的统计信息 |
| -v | 输出inode、文件和其他内核表的统计信息 |
| -d | 输出每一个块设备的活动信息 |
| -r | 输出内存和交换空间的统计信息 |
| -b | 显示I/O和传送速率的统计信息 |
| -a | 文件读写情况 |
| -c | 输出进程统计信息，每秒创建的进程数 |
| -R | 输出内存页面的统计信息 |
| -y | 终端设备活动情况 |
| -w | 输出系统交换活动信息 |
last
概要： 该命令用来列出目前与过去登录系统的用户相关信息。
语法格式： last [-R] [-num] [ -n num ] [-adiowx] [ -f file ] [ -t YYYYMMDDHHMMSS ] [name…] [tty…]
参数：
| 参数 | 说明 |
|---|---|
| -a | 将登录系统的的主机名称或IP地址，显示在最后一行 |
| -d | 将IP地址转换成主机名称 |
| -f | 指定记录文件，默认是显示/var/log目录下的wtmp文件的记录，但/var/log目录下得btmp能显示的内容更丰富，可以显示远程登录，例如ssh登录 ，包括失败的登录请求。 |
| -i | -i显示特定ip登录的情况。跟踪用 -i显示特定ip登录的情况。跟踪用 |
| -n <显示列数>或-<显示列数> | 设置列出名单的显示列数 |
| -R | 不显示登入系统的主机名称或IP（省略 hostname 的栏位） |
| -t | 显示YYYYMMDDHHMMSS之前的信息 |
| -x | 显示系统关闭、用户登录和退出的历史 |
使用示例：
- 显示最后登录系统的N条记录
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> 10 11 12 13 |
<span class="line">[root@ansheng ~]<span class="comment"># last -10</span></span> <span class="line">root pts/0 172.16.10.1 Mon Apr 25 20:06 still logged <span class="keyword">in</span> </span> <span class="line">reboot system boot 2.6.32-573.22.1. Mon Apr 25 20:04 - 20:07 (00:02) </span> <span class="line">root pts/1 172.16.10.1 Mon Apr 25 16:22 - down (02:50) </span> <span class="line">root pts/0 172.16.10.1 Mon Apr 25 08:55 - down (10:17) </span> <span class="line">reboot system boot 2.6.32-573.22.1. Mon Apr 25 08:55 - 19:12 (10:17) </span> <span class="line">root pts/0 172.16.10.1 Sun Apr 24 23:29 - down (00:00) </span> <span class="line">root pts/1 172.16.10.1 Sun Apr 24 21:28 - 22:28 (01:00) </span> <span class="line">root pts/0 172.16.10.1 Sun Apr 24 21:24 - 22:42 (01:17) </span> <span class="line">reboot system boot 2.6.32-573.22.1. Sun Apr 24 21:24 - 23:29 (02:04) </span> <span class="line">root tty1 Sun Apr 24 21:23 - down (00:00) </span> <span class="line">wtmp begins Sat Apr 9 18:06:30 2016</span> |
- 将登录系统的主机名或IP地址显示在最后一行
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> 10 11 12 13 |
<span class="line">[root@ansheng ~]<span class="comment"># last -10 -a</span></span> <span class="line">root pts/0 Mon Apr 25 20:06 still logged <span class="keyword">in</span> 172.16.10.1</span> <span class="line">reboot system boot Mon Apr 25 20:04 - 20:07 (00:03) 2.6.32-573.22.1.el6.x86_64</span> <span class="line">root pts/1 Mon Apr 25 16:22 - down (02:50) 172.16.10.1</span> <span class="line">root pts/0 Mon Apr 25 08:55 - down (10:17) 172.16.10.1</span> <span class="line">reboot system boot Mon Apr 25 08:55 - 19:12 (10:17) 2.6.32-573.22.1.el6.x86_64</span> <span class="line">root pts/0 Sun Apr 24 23:29 - down (00:00) 172.16.10.1</span> <span class="line">root pts/1 Sun Apr 24 21:28 - 22:28 (01:00) 172.16.10.1</span> <span class="line">root pts/0 Sun Apr 24 21:24 - 22:42 (01:17) 172.16.10.1</span> <span class="line">reboot system boot Sun Apr 24 21:24 - 23:29 (02:04) 2.6.32-573.22.1.el6.x86_64</span> <span class="line">root tty1 Sun Apr 24 21:23 - down (00:00) </span> <span class="line">wtmp begins Sat Apr 9 18:06:30 2016</span> |
- 不显示登入系统的主机名称或IP地址
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> 10 11 12 13 |
<span class="line">[root@ansheng ~]<span class="comment"># last -10 -R</span></span> <span class="line">root pts/0 Mon Apr 25 20:06 still logged <span class="keyword">in</span> </span> <span class="line">reboot system boot Mon Apr 25 20:04 - 20:08 (00:03) </span> <span class="line">root pts/1 Mon Apr 25 16:22 - down (02:50) </span> <span class="line">root pts/0 Mon Apr 25 08:55 - down (10:17) </span> <span class="line">reboot system boot Mon Apr 25 08:55 - 19:12 (10:17) </span> <span class="line">root pts/0 Sun Apr 24 23:29 - down (00:00) </span> <span class="line">root pts/1 Sun Apr 24 21:28 - 22:28 (01:00) </span> <span class="line">root pts/0 Sun Apr 24 21:24 - 22:42 (01:17) </span> <span class="line">reboot system boot Sun Apr 24 21:24 - 23:29 (02:04) </span> <span class="line">root tty1 Sun Apr 24 21:23 - down (00:00) </span> <span class="line">wtmp begins Sat Apr 9 18:06:30 2016</span> |
- 将IP地址转换成主机名称
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> 10 11 12 13 |
<span class="line">[root@ansheng ~]<span class="comment"># last -10 -d</span></span> <span class="line">root pts/0 172.16.10.1 Mon Apr 25 20:06 still logged <span class="keyword">in</span> </span> <span class="line">reboot system boot 0.0.0.0 Mon Apr 25 20:04 - 20:09 (00:04) </span> <span class="line">root pts/1 172.16.10.1 Mon Apr 25 16:22 - down (02:50) </span> <span class="line">root pts/0 172.16.10.1 Mon Apr 25 08:55 - down (10:17) </span> <span class="line">reboot system boot 0.0.0.0 Mon Apr 25 08:55 - 19:12 (10:17) </span> <span class="line">root pts/0 172.16.10.1 Sun Apr 24 23:29 - down (00:00) </span> <span class="line">root pts/1 172.16.10.1 Sun Apr 24 21:28 - 22:28 (01:00) </span> <span class="line">root pts/0 172.16.10.1 Sun Apr 24 21:24 - 22:42 (01:17) </span> <span class="line">reboot system boot 0.0.0.0 Sun Apr 24 21:24 - 23:29 (02:04) </span> <span class="line">root tty1 0.0.0.0 Sun Apr 24 21:23 - down (00:00) </span> <span class="line">wtmp begins Sat Apr 9 18:06:30 2016</span> |
lastlog
概要： 用于显示系统中所有用户最近一次登录信息
语法格式： lastlog [选项]
参数：
| 参数 | 说明 |
|---|---|
| -b<天数> | 显示指定天数前的登录信息 |
| -h | 显示召集令的帮助信息 |
| -t<天数> | 显示指定天数以来的登录信息 |
| -u<用户名> | 显示指定用户的最近登录信息 |
使用示例：
- 显示系统中所有用户最近一次登录信息
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 |
<span class="line">[root@ansheng ~]<span class="comment"># lastlog </span></span> <span class="line">Username Port From Latest</span> <span class="line">root pts/0 172.16.10.1 Mon Apr 25 20:06:54 +0800 2016</span> <span class="line">bin **Never logged <span class="keyword">in</span>**</span> <span class="line">daemon **Never logged <span class="keyword">in</span>**</span> <span class="line">adm **Never logged <span class="keyword">in</span>**</span> <span class="line">lp **Never logged <span class="keyword">in</span>**</span> <span class="line">sync **Never logged <span class="keyword">in</span>**</span> <span class="line">shutdown **Never logged <span class="keyword">in</span>**</span> <span class="line">halt **Never logged <span class="keyword">in</span>**</span> <span class="line">mail **Never logged <span class="keyword">in</span>**</span> <span class="line">uucp **Never logged <span class="keyword">in</span>**</span> <span class="line">operator **Never logged <span class="keyword">in</span>**</span> <span class="line">games **Never logged <span class="keyword">in</span>**</span> <span class="line">gopher **Never logged <span class="keyword">in</span>**</span> <span class="line">ftp **Never logged <span class="keyword">in</span>**</span> <span class="line">nobody **Never logged <span class="keyword">in</span>**</span> <span class="line">dbus **Never logged <span class="keyword">in</span>**</span> <span class="line">vcsa **Never logged <span class="keyword">in</span>**</span> <span class="line">abrt **Never logged <span class="keyword">in</span>**</span> <span class="line">haldaemon **Never logged <span class="keyword">in</span>**</span> <span class="line">ntp **Never logged <span class="keyword">in</span>**</span> <span class="line">apache **Never logged <span class="keyword">in</span>**</span> <span class="line">saslauth **Never logged <span class="keyword">in</span>**</span> <span class="line">postfix **Never logged <span class="keyword">in</span>**</span> <span class="line">sshd **Never logged <span class="keyword">in</span>**</span> <span class="line">stap-server **Never logged <span class="keyword">in</span>**</span> <span class="line">oprofile **Never logged <span class="keyword">in</span>**</span> <span class="line">tcpdump **Never logged <span class="keyword">in</span>**</span> <span class="line">ansheng **Never logged <span class="keyword">in</span>**</span> |
history
概要： 查看执行过的命令
语法格式： history [n] history [-c] history [-raw] histfiles
参数：
| 参数 | 说明 |
|---|---|
| n | 数字，意思是‘要列出最近的 n 笔命令列表’的意思 |
| -c | 将目前的 shell 中的所有 history 内容全部消除 |
| -a | 将目前新增的 history 指令新增入 histfiles 中 |
| -r | 将 histfiles 的内容读到目前这个 shell 的 history 记忆中 |
| -w | 将目前的 history 记忆内容写入 histfiles 中 |
| -d | 删除指定行的记录 |
使用示例：
- 列出目前记录的所有history后10行
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> 10 11 |
<span class="line">[root@ansheng ~]<span class="comment"># history |tail -10</span></span> <span class="line"> 436 last -10 -R</span> <span class="line"> 437 last -n 10 <span class="_">-f</span> /var/<span class="built_in">log</span>/btmp</span> <span class="line"> 438 cat /var/<span class="built_in">log</span>/btmp </span> <span class="line"> 439 last -10 <span class="_">-d</span></span> <span class="line"> 440 man <span class="built_in">history</span> </span> <span class="line"> 441 <span class="built_in">history</span> </span> <span class="line"> 442 ls</span> <span class="line"> 443 man <span class="built_in">history</span> </span> <span class="line"> 444 <span class="built_in">history</span> </span> <span class="line"> 445 <span class="built_in">history</span> |tail -10</span> |
- 清空history当前所有历史命令的记录
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> 10 11 12 13 14 |
<span class="line">[root@ansheng ~]<span class="comment"># history 10</span></span> <span class="line"> 455 <span class="built_in">history</span> -10</span> <span class="line"> 456 <span class="built_in">history</span> 10</span> <span class="line"> 457 <span class="built_in">history</span> <span class="_">-d</span> 450</span> <span class="line"> 458 <span class="built_in">history</span> 10</span> <span class="line"> 459 ls</span> <span class="line"> 460 <span class="built_in">pwd</span></span> <span class="line"> 461 ifconfig </span> <span class="line"> 462 <span class="built_in">history</span> 10</span> <span class="line"> 463 <span class="built_in">history</span> <span class="_">-d</span> 460</span> <span class="line"> 464 <span class="built_in">history</span> 10</span> <span class="line">[root@ansheng ~]<span class="comment"># history -c</span></span> <span class="line">[root@ansheng ~]<span class="comment"># history </span></span> <span class="line"> 1 <span class="built_in">history</span></span> |
