1.查询系统状态的常用指令
uname (查看操作系统的内核信息)
Linux
uname -a
Linux EPC-M6G2C 4.1.15 #1 SMP PREEMPT Wed Oct 21 08:03:51 CST 2020 armv7l GNU/Linux
uname -r
4.1.15
cat /proc/cpuinfo
processor : 0
model name : ARMv7 Processor rev 5 (v7l)
BogoMIPS : 24.00
Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xc07
CPU revision : 5
Hardware : Freescale i.MX6 Ultralite (Device Tree)
Revision : 0000
Serial : 0000000000000000
cat /proc/meminfo
MemTotal: 249208 kB
MemFree: 212680 kB
MemAvailable: 220056 kB
Buffers: 0 kB
Cached: 12492 kB
SwapCached: 0 kB
Active: 7016 kB
Inactive: 10024 kB
Active(anon): 4592 kB
Inactive(anon): 756 kB
Active(file): 2424 kB
Inactive(file): 9268 kB
Unevictable: 0 kB
Mlocked: 0 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 249208 kB
LowFree: 212680 kB
SwapTotal: 0 kB
SwapFree: 0 kB
Dirty: 0 kB
Writeback: 0 kB
AnonPages: 4548 kB
Mapped: 9728 kB
Shmem: 800 kB
Slab: 6636 kB
SReclaimable: 2344 kB
SUnreclaim: 4292 kB
KernelStack: 400 kB
PageTables: 300 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 124604 kB
Committed_AS: 8244 kB
VmallocTotal: 1810432 kB
VmallocUsed: 5496 kB
VmallocChunk: 1628460 kB
CmaTotal: 32768 kB
CmaFree: 24072 kB
hostname
EPC-M6G2C
free
total used free shared buffers
Mem: 249208 36528 212680 800 0
-/+ buffers: 36528 212680
Swap: 0 0 0
Mem 内存的使用信息
buff/cache 被 buffer (缓冲区)和 cache (高速缓冲存储器)使用的物理内存大小
Swap 交换空间的使用信息
total 系统总的可用物理内存大小
used 已被使用的物理内存大小
free还有多少物理内存可用
shared 被共享使用的物理内存大小
available 还可以被使用的物理内存大小（即系统可用内存约等于free+shared+buff/cache）
top top查看进程运行情况 ( top -H -p 进程ID 查看线程运行情况)
Mem: 36528K used, 212680K free, 800K shrd, 0K buff, 12492K cached
CPU: 0% usr 0% sys 0% nic 99% idle 0% io 0% irq 0% sirq
Load average: 0.00 0.01 0.05 1/51 342
PID PPID USER STAT VSZ %VSZ %CPU COMMAND
237 1 root S 34808 14% 0% ./mh3200cems -qws
342 281 root R 2096 1% 0% top
151 1 root S 2500 1% 0% /sbin/udevd -d
185 1 dbus S 2232 1% 0% dbus-daemon --system
281 1 root S 2096 1% 0% -sh
1 0 root S 1992 1% 0% init
146 1 root S 1992 1% 0% /sbin/syslogd -n
149 1 root S 1992 1% 0% /sbin/klogd -n
215 1 root S 1992 1% 0% /usr/sbin/telnetd -F
204 1 root S 1880 1% 0% /usr/sbin/dropbear -R
225 1 root S 1464 1% 0% /usr/local/webs/bin/webs
175 1 daemon S 1372 1% 0% portmap
68 2 root SW 0 0% 0% [irq/26-2040000.]
19 2 root SW 0 0% 0% [kworker/0:1]
306 2 root SW 0 0% 0% [kworker/0:0]
7 2 root SW 0 0% 0% [rcu_preempt]
3 2 root SW 0 0% 0% [ksoftirqd/0]
6 2 root SW 0 0% 0% [kworker/u2:0]
2 0 root SW 0 0% 0% [kthreadd]
12 2 root SW 0 0% 0% [kdevtmpfs]
ps aux
PID USER COMMAND
1 root init
2 root [kthreadd]
3 root [ksoftirqd/0]
5 root [kworker/0:0H]
fdisk -l //看到的是物理磁盘大小（包括swap分区的物理大小）
blk_update_request: I/O error, dev mtdblock0, sector 0
blk_update_request: I/O error, dev mtdblock0, sector 0
Buffer I/O error on dev mtdblock0, logical block 0, async page read
Disk /dev/mtdblock1: 1 MB, 1048576 bytes
255 heads, 63 sectors/track, 0 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/mtdblock1 doesn't contain a valid partition table
Disk /dev/mtdblock2: 8 MB, 8388608 bytes
255 heads, 63 sectors/track, 1 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/mtdblock2 doesn't contain a valid partition table
Disk /dev/mtdblock3: 8 MB, 8388608 bytes
255 heads, 63 sectors/track, 1 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/mtdblock3 doesn't contain a valid partition table
Disk /dev/mtdblock4: 4 MB, 4194304 bytes
255 heads, 63 sectors/track, 0 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/mtdblock4 doesn't contain a valid partition table
Disk /dev/mtdblock5: 76 MB, 76546048 bytes
255 heads, 63 sectors/track, 9 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/mtdblock5 doesn't contain a valid partition table
Disk /dev/mtdblock6: 165 MB, 165675008 bytes
255 heads, 63 sectors/track, 20 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/mtdblock6 doesn't contain a valid partition table
df -h //看到的是文件系统使用状况（不包括swap分区）
Filesystem Size Used Available Use% Mounted on
ubi0:rootfs 58.6M 52.5M 6.1M 90% /
devtmpfs 105.4M 0 105.4M 0% /dev
tmpfs 121.7M 0 121.7M 0% /dev/shm
tmpfs 121.7M 632.0K 121.1M 1% /tmp
tmpfs 121.7M 164.0K 121.5M 0% /run
ubi1_0 134.7M 37.2M 92.9M 29% /opt
cat /proc/version
Linux version 4.1.15 (administrator@administrator-virtual-machine) (gcc version 4.9.2
20140904 (prerelease) ( crosstool-NG linaro-1.13.1-4.9-2014.09 - Linaro GCC 4.9-
2014.09) ) #1 SMP PREEMPT Wed Oct 21 08:03:51 CST 2020
hostname(查看服务器名称)
EPC-M6G2C