机能阐明

vmstat

虚拟内存统计

用法

Usage:
 vmstat [options] [delay [count]]

Options:
 -a, --active           active/inactive memory
 -f, --forks            number of forks since boot
 -m, --slabs            slabinfo
 -n, --one-header       do not redisplay header
 -s, --stats            event counter statistics
 -d, --disk             disk statistics
 -D, --disk-sum         summarize disk statistics
 -p, --partition <dev>  partition specific statistics
 -S, --unit <char>      define display unit
 -w, --wide             wide output
 -t, --timestamp        show timestamp

 -h, --help     display this help and exit
 -V, --version  output version information and exit

示例

[root@localhost ~]# vmstat
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 0  0  71256  92720      0 565120    0    0     1   115   22   36  1  0 99  0  0

个中

free

内存利用状况

[root@localhost ~]# free
              total        used        free      shared  buff/cache   available
Mem:        1849336     1193336       90344        1752      565656      460000
Swap:       2097148       71248     2025900
[root@localhost ~]# free -h
              total        used        free      shared  buff/cache   available
Mem:           1.8G        1.1G         88M        1.7M        552M        449M
Swap:          2.0G         69M        1.9G
[root@localhost ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:           1805        1165          88           1         552         449
Swap:          2047          69        1978
[root@localhost ~]# free -h 2
              total        used        free      shared  buff/cache   available
Mem:           1.8G        1.1G         88M        1.7M        552M        449M
Swap:          2.0G         69M        1.9G
[root@localhost ~]# free -h -s 2
              total        used        free      shared  buff/cache   available
Mem:           1.8G        1.1G         88M        1.7M        552M        449M
Swap:          2.0G         69M        1.9G

              total        used        free      shared  buff/cache   available
Mem:           1.8G        1.1G         88M        1.7M        552M        449M
Swap:          2.0G         69M        1.9G

              total        used        free      shared  buff/cache   available
Mem:           1.8G        1.1G         88M        1.7M        552M        449M
Swap:          2.0G         69M        1.9G

uptime

统计当前系统的运行环境

[root@localhost ~]# uptime
 09:59:55 up 2 days, 7 min,  1 user,  load average: 0.00, 0.01, 0.05

load average: 系统 1分钟，5分钟，15分钟的平均负荷

netstat

当前网络信息

用法

usage: netstat [-vWeenNcCF] [<Af>] -r         netstat {-V|--version|-h|--help}
       netstat [-vWnNcaeol] [<Socket> ...]
       netstat { [-vWeenNac] -I[<Iface>] | [-veenNac] -i | [-cnNe] -M | -s [-6tuw] } [delay]

        -r, --route              display routing table
        -I, --interfaces=<Iface> display interface table for <Iface>
        -i, --interfaces         display interface table
        -g, --groups             display multicast group memberships
        -s, --statistics         display networking statistics (like SNMP)
        -M, --masquerade         display masqueraded connections

        -v, --verbose            be verbose
        -W, --wide               don't truncate IP addresses
        -n, --numeric            don't resolve names
        --numeric-hosts          don't resolve host names
        --numeric-ports          don't resolve port names
        --numeric-users          don't resolve user names
        -N, --symbolic           resolve hardware names
        -e, --extend             display other/more information
        -p, --programs           display PID/Program name for sockets
        -o, --timers             display timers
        -c, --continuous         continuous listing

        -l, --listening          display listening server sockets
        -a, --all                display all sockets (default: connected)
        -F, --fib                display Forwarding Information Base (default)
        -C, --cache              display routing cache instead of FIB
        -Z, --context            display SELinux security context for sockets

  <Socket>={-t|--tcp} {-u|--udp} {-U|--udplite} {-w|--raw} {-x|--unix}
           --ax25 --ipx --netrom
  <AF>=Use '-6|-4' or '-A <af>' or '--<af>'; default: inet
  List of possible address families (which support routing):
    inet (DARPA Internet) inet6 (IPv6) ax25 (AMPR AX.25)
    netrom (AMPR NET/ROM) ipx (Novell IPX) ddp (Appletalk DDP)
    x25 (CCITT X.25)