sysadmin_basement

基本部分

1. 系统硬件

1.1. 主板

获取序列号

$ sudo dmidecode -t system |grep -i Serial

Serial Number: CNU9032T3N

获取厂商和型号

$ sudo dmidecode -t system

= dmidecode 2.11

SMBIOS 2.4 present.

Handle 0x0001, DMI type 1, 27 bytes

System Information

        Manufacturer: Hewlett-Packard

        Product Name: HP 540

Version: F.02

Serial Number: CNU9032T3N

UUID: 7E2B6111-7C15-E011-5A8C-6D991201D929

Wake-up Type: Power Switch

SKU Number: NL385PA=AB2

Family: 103C_5336AN

Handle 0x0012, DMI type 32, 11 bytes

System Boot Information

Status: No errors detected

获取出厂日期

$ sudo dmidecode -t bios|grep -i date

Release Date: 08/20/2008

1.2. CPU

/proc/cpuinfo

$ cat /proc/cpuinfo

processor       : 0

vendor_id       : GenuineIntel

cpu family      : 6

model           : 15

model name      : Genuine Intel(R) CPU           T1400  @ 1.73GHz

stepping        : 13

microcode       : 0xa3

cpu MHz         : 1729.060

cache size      : 512 KB

physical id     : 0

siblings        : 2

core id         : 0

cpu cores       : 2

apicid          : 0

initial apicid  : 0

fdiv_bug        : no

hlt_bug         : no

f00f_bug        : no

coma_bug        : no

fpu             : yes

fpu_exception   : yes

cpuid level     : 10

wp              : yes

flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl tm2 ssse3 cx16 xtpr pdcm lahf_lm dtherm

bogomips        : 3458.12

clflush size    : 64

cache_alignment : 64

address sizes   : 36 bits physical, 48 bits virtual

power management:

lscpu

$ lscpu

Architecture:          x86_64

CPU op-mode(s):        32-bit, 64-bit

CPU(s):                24

Thread(s) per core:    2

Core(s) per socket:    6

CPU socket(s):         2

NUMA node(s):          2

Vendor ID:             GenuineIntel

CPU family:            6

Model:                 44

Stepping:              2

CPU MHz:               2526.869

Virtualization:        VT-x

L1d cache:             32K

L1i cache:             32K

L2 cache:              256K

L3 cache:              12288K

dmidecode -t processor

$ sudo dmidecode -t processor

= dmidecode 2.11

SMBIOS 2.4 present.

Handle 0x0004, DMI type 4, 35 bytes

Processor Information

Socket Designation: U10

Type: Central Processor

Family: Pentium M

Manufacturer: Intel(R)

ID: FD 06 00 00 FF FB EB BF

Signature: Type 0, Family 6, Model 15, Stepping 13

Flags:

        FPU (Floating-point unit on-chip)

        VME (Virtual mode extension)

        DE (Debugging extension)

        PSE (Page size extension)

        TSC (Time stamp counter)

        MSR (Model specific registers)

        PAE (Physical address extension)

        MCE (Machine check exception)

        CX8 (CMPXCHG8 instruction supported)

        APIC (On-chip APIC hardware supported)

        SEP (Fast system call)

        MTRR (Memory type range registers)

        PGE (Page global enable)

        MCA (Machine check architecture)

        CMOV (Conditional move instruction supported)

        PAT (Page attribute table)

        PSE-36 (36-bit page size extension)

        CLFSH (CLFLUSH instruction supported)

        DS (Debug store)

        ACPI (ACPI supported)

        MMX (MMX technology supported)

        FXSR (FXSAVE and FXSTOR instructions supported)

        SSE (Streaming SIMD extensions)

        SSE2 (Streaming SIMD extensions 2)

        SS (Self-snoop)

        HTT (Multi-threading)

        TM (Thermal monitor supported)

        PBE (Pending break enabled)

Version: Genuine Intel(R) CPU           T1400  @ 1.73GHz

Voltage: 1.1 V

External Clock: 133 MHz

Max Speed: 1733 MHz

Current Speed: 1733 MHz

Status: Populated, Enabled

Upgrade: None

L1 Cache Handle: 0x0005

L2 Cache Handle: 0x0006

L3 Cache Handle: Not Provided

Serial Number: Not Specified

Asset Tag: Not Specified

Part Number: Not Specified

1.3. 内存

/proc/meminfo

$  cat /proc/meminfo

MemTotal:        1016844 kB

MemFree:          107484 kB

Buffers:          470592 kB

Cached:           110684 kB

SwapCached:          904 kB

Active:           262476 kB

Inactive:         453672 kB

Active(anon):      24572 kB

Inactive(anon):   142096 kB

Active(file):     237904 kB

Inactive(file):   311576 kB

Unevictable:           0 kB

Mlocked:               0 kB

HighTotal:        126664 kB

HighFree:           5312 kB

LowTotal:         890180 kB

LowFree:          102172 kB

SwapTotal:       1038332 kB

SwapFree:        1005956 kB

Dirty:                 0 kB

Writeback:             0 kB

AnonPages:        134068 kB

Mapped:            19084 kB

Shmem:             31796 kB

Slab:             174980 kB

SReclaimable:     162588 kB

SUnreclaim:        12392 kB

KernelStack:        1664 kB

PageTables:         2940 kB

NFS_Unstable:          0 kB

Bounce:                0 kB

WritebackTmp:          0 kB

CommitLimit:     1546752 kB

Committed_AS:     404708 kB

VmallocTotal:     122880 kB

VmallocUsed:       12628 kB

VmallocChunk:     108240 kB

HardwareCorrupted:     0 kB

AnonHugePages:         0 kB

HugePages_Total:       0

HugePages_Free:        0

HugePages_Rsvd:        0

HugePages_Surp:        0

Hugepagesize:       2048 kB

DirectMap4k:       32760 kB

DirectMap2M:      880640 kB

dmidecode -t memory

$ sudo dmidecode -t memory

= dmidecode 2.11

SMBIOS 2.4 present.

Handle 0x000A, DMI type 16, 15 bytes

Physical Memory Array

Location: System Board Or Motherboard

Use: System Memory

Error Correction Type: None

Maximum Capacity: 4 GB

Error Information Handle: No Error

Number Of Devices: 2

Handle 0x000B, DMI type 17, 27 bytes

Memory Device

Array Handle: 0x000A

Error Information Handle: No Error

Total Width: Unknown

Data Width: Unknown

Size: No Module Installed

Form Factor: SODIMM

Set: None

Locator: DIMM =1

Bank Locator: Not Specified

Type: DDR2

Type Detail: Synchronous

Speed: Unknown

Manufacturer:

Serial Number:

Asset Tag: Not Specified

Part Number:

Handle 0x000C, DMI type 17, 27 bytes

Memory Device

Array Handle: 0x000A

Error Information Handle: No Error

Total Width: 64 bits

Data Width: 64 bits

Size: 1024 MB

Form Factor: SODIMM

Set: None

Locator: DIMM =2

Bank Locator: Not Specified

Type: DDR2

Type Detail: Synchronous

Speed: 667 MHz

Manufacturer: Hyundai Electronics

Serial Number: 04008096

Asset Tag: Not Specified

Part Number: HYMP112S64CP6-Y5

获取内存插槽数，每条内存大小

$  sudo dmidecode -t memory |grep -i size

Size: 8192 MB

Size: 8192 MB

Size: 8192 MB

Size: 8192 MB

Size: 8192 MB

Size: 8192 MB

Size: No Module Installed

Size: No Module Installed

Size: No Module Installed

Size: 8192 MB

Size: 8192 MB

Size: 8192 MB

Size: 8192 MB

Size: 8192 MB

Size: 8192 MB

Size: No Module Installed

Size: No Module Installed

Size: No Module Installed

获取最大支持内存

$  sudo dmidecode -t memory |grep -i max

Maximum Capacity: 288 GB

获取内存频率

$  sudo dmidecode -t memory |grep -i speed

Speed: 1333 MHz (0.8 ns)

Speed: 1333 MHz (0.8 ns)

Speed: 1333 MHz (0.8 ns)

Speed: 1333 MHz (0.8 ns)

Speed: 1333 MHz (0.8 ns)

Speed: 1333 MHz (0.8 ns)

Speed: Unknown

Speed: Unknown

Speed: Unknown

Speed: 1333 MHz (0.8 ns)

Speed: 1333 MHz (0.8 ns)

Speed: 1333 MHz (0.8 ns)

Speed: 1333 MHz (0.8 ns)

Speed: 1333 MHz (0.8 ns)

Speed: 1333 MHz (0.8 ns)

Speed: Unknown

Speed: Unknown

Speed: Unknown

1.4. 硬盘

1.4.1. lspci

LSI MagaSAS

$ lspci |grep -i raid

03:00.0 RAID bus controller: LSI Logic / Symbios Logic LSI MegaSAS 9260 (rev 05)

megacli

megasasctl/megactl

megaraidsas-status/megaraid-status

megclisas-status

megamgr

Adaptec

$ lspci |grep -i raid

02:00.0 RAID bus controller: Adaptec AAC-RAID (rev 09)

arcconf

1.4.2. lsscsi

lsscsi

$ sudo lsscsi

[0:0:0:0]    cd/dvd  Dell     Virtual  CDROM   123   /dev/scd0

[1:0:0:0]    disk    Dell     Virtual  Floppy  123   /dev/sdc

[2:0:0:0]    disk    ATA      Maxtor 7L250S0   1G10  /dev/sda

[2:0:4:0]    disk    SEAGATE  ST3300555SS      T105  /dev/sdb

/proc/scsi/scsi

$ cat /proc/scsi/scsi

Attached devices:

Host: scsi2 Channel: 00 Id: 00 Lun: 00

  Vendor: ATA      Model: Maxtor 7L250S0   Rev: 1G10

  Type:   Direct-Access                    ANSI SCSI revision: 05

Host: scsi0 Channel: 00 Id: 00 Lun: 00

  Vendor: Dell     Model: Virtual  CDROM   Rev: 123

  Type:   CD-ROM                           ANSI SCSI revision: 02

Host: scsi1 Channel: 00 Id: 00 Lun: 00

  Vendor: Dell     Model: Virtual  Floppy  Rev: 123

  Type:   Direct-Access                    ANSI SCSI revision: 02

Host: scsi2 Channel: 00 Id: 04 Lun: 00

  Vendor: SEAGATE  Model: ST3300555SS      Rev: T105

  Type:   Direct-Access                    ANSI SCSI revision: 05

1.4.3. smartctl

smartctl -a /dev/sda

$ sudo smartctl -a /dev/sda

=== START OF INFORMATION SECTION ===

Model Family:     Hitachi Travelstar 5K320

Device Model:     Hitachi HTS543216L9A300

Serial Number:    090107FB0200LCJJVXPB

LU WWN Device Id: 5 000cca 561e3da05

Firmware Version: FB2OC40F

User Capacity:    160,041,885,696 bytes [160 GB]

Sector Size:      512 bytes logical/physical

Device is:        In smartctl database [for details use: -P show]

ATA Version is:   8

ATA Standard is:  ATA-8-ACS revision 3f

Local Time is:    Tue Mar 26 12:52:42 2013 CST

SMART support is: Available - device has SMART capability.

SMART support is: Enabled

smartctl -a -d megaraid,1 /dev/sda

smartctl -a /dev/sda|grep -i serial

$ sudo smartctl -a /dev/sda|grep -i serial

Serial Number:    090107FB0200LCJJVXPB

1.5. 网卡

1.5.1. 网卡类型

$ lspci|grep -i net

16:00.0 Ethernet controller: Emulex Corporation OneConnect 10Gb NIC (be3) (rev 03)

05:00.0 Ethernet controller: Broadcom Corporation NetXtreme II BCM5708 Gigabit Ethernet (rev 12)

00:19.0 Ethernet controller: Intel Corporation 82562GT 10/100 Network Connection (rev 03)

10:00.0 Network controller: Broadcom Corporation BCM4312 802.11b/g LP-PHY (rev 01)

1.5.2. 网卡驱动

升级系统的时候，就要查看下网卡驱动安装上了没，尤其是bnx系列网卡特别要注意

$ update-initramfs -u -k \`uname -r\`

1.5.3. 查看工具

ethtool

$  sudo ethtool eth0

Settings for eth0:

Supported ports: [ TP ]

Supported link modes:   10baseT/Half 10baseT/Full

                        100baseT/Half 100baseT/Full

Supported pause frame use: No

Supports auto-negotiation: Yes

Advertised link modes:  10baseT/Half 10baseT/Full

                        100baseT/Half 100baseT/Full

Advertised pause frame use: No

Advertised auto-negotiation: Yes

Speed: 100Mb/s

Duplex: Full

Port: Twisted Pair

PHYAD: 1

Transceiver: internal

Auto-negotiation: on

MDI-X: off

Supports Wake-on: pumbg

Wake-on: g

Current message level: 0x00000001 (1)

                       drv

Link detected: yes

mii－tool

$ sudo mii-tool

eth0: negotiated 1000baseT-FD flow-control, link ok

eth1: negotiated 1000baseT-FD flow-control, link ok

SIOCGMIIPHY on 'eth2' failed: Resource temporarily unavailable

SIOCGMIIPHY on 'eth3' failed: Resource temporarily unavailable

ip addr

$  ip addr

    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN

link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

inet 127.0.0.1/8 scope host lo

inet6 ::1/128 scope host

   valid_lft forever preferred_lft forever

    2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

link/ether 00:24:81:36:37:a7 brd ff:ff:ff:ff:ff:ff

inet 192.168.144.242/22 brd 192.168.147.255 scope global eth0

inet6 fe80::224:81ff:fe36:37a7/64 scope link

   valid_lft forever preferred_lft forever

    3: eth2: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000

link/ether 00:21:00:a4:49:f6 brd ff:ff:ff:ff:ff:ff

2. 内存

2.1. free

$  free -m

     total       used       free     shared    buffers     cached

Mem:           993        914         78          0        132        607

-/+ buffers/cache:        174        818

Swap:         1013         10       1003

free 详解

1. total: 内存总数

2. used：已经使用的内存数

3. free： 空闲的内存数

4. shared： 多个进程共享的内存总额

5. -buffers/cache: （已用）的内存数，即used-buffers-cached //反映实际被用掉的内存数

6. +buffers/cache: (可用)的内存数，即free+buffers+cached //反映可以使用的内存数

可用内存的计算公式为：

   可用内存=free+buffers+cached,即399M+109M+723M=1232M

内存总数与已使用内存数和空闲内存数的关系：

 total（1968M）=used（1569M）+free（399M）

注：观察Linux的内存使用情况时，只要没有发现用swap的交换空间，就不用担心自己的内存太少；如果常常看到swap用了很多，那么就要考虑增加物理内存了。这也是在Linux服务器上看内存是否够用的标准。

2.2. vmstat

vmstat 1

$ vmstat -S M 1 5

procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----

r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa

1  0      1  56541    384  36313    0    0    10   152    0    0  3  1 95  1

1  0      1  56543    384  36313    0    0   128   168 7271 11527  1  0 99  0

0  0      1  56542    384  36313    0    0     0   112 6045 9615  1  0 99  0

0  0      1  56543    384  36313    0    0   132   192 11305 17468  1  1 98  0

0  0      1  56539    384  36313    0    0   128   456 13028 20222  1  1 98  0

vmstat -a

$ vmstat -S M 1 5 -a

procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----

r  b   swpd   free  inact active   si   so    bi    bo   in   cs us sy id wa

 2  0      1  56540  30690   7020    0    0    10   152    0    0  3  1 95  1

1  0      1  56543  30690   7017    0    0   128   200 8258 12908  1  1 99  0

0  0      1  56540  30691   7020    0    0     0   176 8696 13414  1  1 98  0

1  0      1  56543  30691   7017    0    0   128  1116 11617 17652  1  0 98  0

0  0      1  56541  30691   7019    0    0     0   176 7946 12529  1  0 99  0

vmstat -s

$ vmstat -s

   99197360 K total memory

   41313428 K used memory

    7193792 K active memory

   31438464 K inactive memory

   57883936 K free memory

     394068 K buffer memory

   37204624 K swap cache

    2096444 K total swap

       1992 K used swap

    2094452 K free swap

 1277643835 non-nice user cpu ticks

         11 nice user cpu ticks

  371033881 system cpu ticks

41192773129 idle cpu ticks

  247499620 IO-wait cpu ticks

      39100 IRQ cpu ticks

   48138900 softirq cpu ticks

          0 stolen cpu ticks

 4450333523 pages paged in

65678511936 pages paged out

     132467 pages swapped in

     180917 pages swapped out

 1237774778 interrupts

 3301154853 CPU context switches

 1346296992 boot time

   44515969 forks

2.3. ps

ps aux
ps -e -o "%c : %p : %z :%a" |sort -k5 -nr|head

2.4. dstat

dstat -ms

$ dstat -ms 1 5

------memory-usage----- ----swap---

 used  buff  cach  free| used  free

3639M  385M 35.6G 55.1G|1992k 2045M

3641M  385M 35.6G 55.1G|1992k 2045M

3638M  385M 35.6G 55.1G|1992k 2045M

3638M  385M 35.6G 55.1G|1992k 2045M

3638M  385M 35.6G 55.1G|1992k 2045M

3641M  385M 35.6G 55.1G|1992k 2045M

dstat --top-mem

$ dstat --top-mem 1 5

--most-expensive-

  memory process

mongod      35.0G

mongod      35.0G

mongod      35.0G

mongod      35.0G

mongod      35.0G

mongod      35.0G

dstat -v

$ dstat -v 1 5

---procs--- ------memory-usage----- ---paging-- -dsk/total- ---system-- ----total-cpu-usage----

run blk new| used  buff  cach  free|  in   out | read  writ| int   csw |usr sys idl wai hiq siq

0.0   0 2.5|3649M  385M 35.6G 55.1G|  30B   41B| 247k 3638k|3162    20k|  3   1  95   1   0   0

3.0   0 2.0|3646M  385M 35.6G 55.1G|   0     0 |   0   144k|7217    11k|  1   1  99   0   0   0

  0   0 1.0|3650M  385M 35.6G 55.1G|   0     0 | 176k  376k|  17k   28k|  1   1  98   0   0   0

1.0   0 1.0|3647M  385M 35.6G 55.1G|   0     0 | 128k  160k|8258    13k|  1   0  99   0   0   0

1.0   0 5.0|3648M  385M 35.6G 55.1G|   0     0 |   0   120k|8138    12k|  1   1  99   0   0   0

  0   0 1.0|3646M  385M 35.6G 55.1G|   0     0 | 128k  336k|  15k   23k|  1   1  98   0   0   0

2.5. top

2.6. slabtop

2.7. buffer 与 cache

buffer与cache操作的对象不一样。

buffer(缓冲)是为了提高内存和硬盘(或其它I/O设备)之间的数据交换的速度而设计的。

cache(缓存)是为了提高cpu和内存之间的数据交换而设计的，也就是平常见到的一级缓存、二级缓存、三级缓存等。

cpu在执行程序所用的指令和读数据都是针对内存的，也就是从内存中取得的。由于内存的读写速度慢，为了提高cpu和内存之间的数据交换的速度，在cpu 和内存之间增加了cache，他的速度比内存块，但是造价高，又由于在cpu内不能集成太对集成电路，所以一般cache比较小，以后intel等公司为了进一步提高速度，又增加了二级cache，甚至三级cache，它是根据程序的局部性原理而设计的，就是cpu执行的指令和访问的数据往往在集中的某一块，所以把这块内容放入cache后，cpu就不用再访问内存了，这就提高了访问速度。当然若cache中没有cpu所需要的内容，还是要访问内存的。

缓冲(buffers) 是根据磁盘的读写设计的，把分散的写操作集中进行，减少了磁盘碎片和硬盘的反复寻道，从而提高系统性能。linux有一个守护进程定期清空缓冲内容(即写入磁盘)，也可以通过sync命令手动清空缓冲。举个例子吧：我这里有一个ext2的U盘，我往里面copy一个3M的MP3.但U盘的灯没有跳动，过了一会儿(或者手动输入sync)U盘的灯就跳动起来了。卸载设备时会清空缓冲，所以有些时候卸载一个设备要等上几秒钟。

修改/etc/sysctl.conf中的vm.swappiness右边的数字可以在下次开机时调节swap使用策略。该数字范围是0-100，数字越大越倾向于使用swap。默认为60，可以改一下试试。--两者都是RAM中的数据。

简单来说，buffer是即将要写入磁盘的，而cache是被从磁盘中读出来的。

buffer是由各种进程分配的，被用在如输入队列等方面。一个简单的例子如某个进程要求有多个字段读入，在所有字段被读入完整之前，进程就先前读入的字段放在buffer中保存。

cache经常被用在磁盘的I/O请求上，如果有多个进程都要访问某个文件，于是该文件便被做成cache以方便下次被访问，这样可提高系统性能。

3. CPU和进程状态

3.1. CPU

3.1.1. top

整体占用

$ top

top - 11:49:30 up 3 days, 16:54,  1 user,  load average: 4.18, 3.82, 3.82

Tasks: 294 total,   4 running, 290 sleeping,   0 stopped,   0 zombie

%Cpu(s): 16.6 us,  0.3 sy,  0.0 ni, 83.0 id,  0.0 wa,  0.0 hi,  0.1 si,  0.0 st

KiB Mem:  99197352 total, 51128244 used, 48069108 free,   797128 buffers

KiB Swap:  2096444 total,        0 used,  2096444 free, 44232372 cached

us, user    : time running un-niced user processes

sy, system  : time running kernel processes

ni, nice    : time running niced user processes

wa, IO-wait : time waiting for I/O completion

hi : time spent servicing hardware interrupts

si : time spent servicing software interrupts

st : time stolen from this vm by the hypervisor

单核占用(按数字1即可查看)

top - 11:50:19 up 3 days, 16:55,  1 user,  load average: 4.33, 3.94, 3.86

Tasks: 294 total,   5 running, 289 sleeping,   0 stopped,   0 zombie

%Cpu0  : 71.7 us,  1.6 sy,  0.0 ni, 26.8 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu1  :100.0 us,  0.0 sy,  0.0 ni,  0.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu2  : 48.8 us,  1.6 sy,  0.0 ni, 48.8 id,  0.0 wa,  0.0 hi,  0.8 si,  0.0 st

%Cpu3  :  6.5 us,  0.8 sy,  0.0 ni, 92.7 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu4  : 11.5 us,  1.6 sy,  0.0 ni, 86.9 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu5  :  8.2 us,  0.0 sy,  0.0 ni, 91.8 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu6  : 10.6 us,  1.6 sy,  0.0 ni, 87.8 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu7  : 17.9 us,  0.8 sy,  0.0 ni, 81.3 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu8  : 18.0 us,  0.0 sy,  0.0 ni, 82.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu9  :  0.8 us,  0.0 sy,  0.0 ni, 99.2 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu10 :  4.0 us,  0.8 sy,  0.0 ni, 95.2 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu11 :  0.8 us,  0.0 sy,  0.0 ni, 99.2 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu12 :  0.0 us,  0.0 sy,  0.0 ni,100.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu13 :  0.0 us,  0.0 sy,  0.0 ni,100.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu14 :  0.0 us,  0.0 sy,  0.0 ni,100.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu15 :  0.0 us,  0.0 sy,  0.0 ni,100.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu16 :  0.0 us,  1.6 sy,  0.0 ni, 98.4 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu17 :  0.0 us,  0.0 sy,  0.0 ni,100.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu18 :  0.0 us,  0.0 sy,  0.0 ni,100.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu19 :  0.0 us,  0.0 sy,  0.0 ni,100.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu20 :  0.0 us,  0.0 sy,  0.0 ni,100.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu21 :  0.8 us,  0.0 sy,  0.0 ni, 99.2 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu22 :  0.0 us,  0.0 sy,  0.0 ni,100.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

%Cpu23 :  0.0 us,  0.8 sy,  0.0 ni, 99.2 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

KiB Mem:  99197352 total, 51119700 used, 48077652 free,   797228 buffers

KiB Swap:  2096444 total,        0 used,  2096444 free, 44230160 cached

3.1.2. ps

ps aux

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND

root         1  0.0  0.0  10648   696 ?        Ss    2012   2:39 init [2]

root         2  0.0  0.0      0     0 ?        S     2012   0:00 [kthreadd]

root         3  0.0  0.0      0     0 ?        S     2012  15:37 [ksoftirqd/0]

root         5  0.0  0.0      0     0 ?        S     2012   7:29 [kworker/u:0]

root         6 69.3  0.0      0     0 ?        S     2012 260714:15 [migration/0]

cpu占用排名前十

ps -e -o "%c : %p : %z :%a" |sort -k5 -nr|head

3.1.3. vmstat

vmstat 1

procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----

 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa

 2  0      1  54362    656  21028    0    0     8   135    0    0  3  1 95  0

 1  0      1  54340    656  21046    0    0     0    64 23399 38962  5  1 93  0

 1  0      1  54322    656  21064    0    0     0   236 3714 4284  5  0 95  0

 1  0      1  54303    656  21082    0    0     0    40 5053 6121  5  1 95  0

 2  0      1  54285    656  21101    0    0     0     0 11561 7237  5  1 94  0

 2  0      1  54265    656  21118    0    0     0    52 12087 19945  5  1 95  0

 1  0      1  54245    656  21136    0    0     0   172 17392 28452  5  1 94  0

 1  0      1  54227    656  21154    0    0     0     0 3600 4315  4  0 95  0

 1  0      1  54210    656  21172    0    0     0     0 6312 8115  5  0 95  0

 2  0      1  54189    656  21190    0    0     0   200 9554 17258  5  1 94  0

us: Time spent running non-kernel code.  (user time, including nice time)

sy: Time spent running kernel code.  (system time)

id: Time spent idle.  Prior to Linux 2.5.41, this includes IO-wait time.

wa: Time spent waiting for IO.  Prior to Linux 2.5.41, included in idle.

st: Time stolen from a virtual machine.  Prior to Linux 2.6.11, unknown.

3.1.4. dstat

dstat

----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system--

usr sys idl wai hiq siq| read  writ| recv  send|  in   out | int   csw

  3   1  95   0   0   0| 201k 3220k|   0     0 |  24B   33B|4502    25k

  5   1  94   0   0   0|   0     0 | 715k  477k|   0     0 |7078  9979

  5   1  95   0   0   0|   0   320k| 216k  140k|   0     0 |5786  8076

  5   0  95   0   0   0|   0     0 | 195k  124k|   0     0 |4611  5927

  5   1  94   0   0   0|   0   184k| 191k  111k|   0     0 |  16k   27k

  5   1  94   0   0   0|   0   176k| 399k  302k|   0     0 |  14k   23k

  5   1  94   0   0   0|   0   220k|3315k  288k|   0     0 |  15k   24k

  5   1  94   0   0   0|   0   160k| 791k  281k|   0     0 |  10k   15k

  5   1  94   0   0   0|   0   148k|1459k  252k|   0     0 |  12k   17k

  4   0  95   0   0   0|   0     0 | 407k  186k|   0     0 |3458  3454

  5   0  95   0   0   0|   0    76k| 192k   86k|   0     0 |6801  9760

dstat -v

---procs--- ------memory-usage----- ---paging-- -dsk/total- ---system-- ----total-cpu-usage----

run blk new| used  buff  cach  free|  in   out | read  writ| int   csw |usr sys idl wai hiq siq

0.0   0 2.6|20.1G  656M 19.3G 54.5G|  24B   33B| 201k 3220k|4502    25k|  3   1  95   0   0   0

1.0   0 3.0|20.1G  656M 19.3G 54.5G|   0     0 |   0   268k|  19k   30k|  1   1  97   0   0   0

1.0   0 1.0|20.1G  656M 19.3G 54.5G|   0     0 |   0     0 |4471  6321 |  1   0  99   0   0   0

1.0   0 2.0|20.1G  656M 19.3G 54.5G|   0     0 |   0    64k|5223  8064 |  1   1  99   0   0   0

  0   0 2.0|20.1G  656M 19.3G 54.5G|   0     0 |   0   208k|  18k   30k|  1   1  97   0   0   0

  0   0 1.0|20.1G  656M 19.3G 54.5G|   0     0 |   0   156k|8036    12k|  1   1  99   0   0   0

1.0   0 1.0|20.1G  656M 19.3G 54.5G|   0     0 |   0   160k|  16k   27k|  1   1  97   0   0   0

1.0   0 3.0|20.1G  656M 19.3G 54.5G|   0     0 |   0   148k|7654    11k|  1   1  98   0   0   0

1.0   0 1.0|20.1G  656M 19.3G 54.5G|   0     0 |   0   148k|  15k   21k|  3   1  97   0   0   0

  0   0 3.0|20.1G  656M 19.3G 54.5G|   0     0 |   0     0 |5672  6959 |  1   1  99   0   0   0

  0   0 1.0|20.1G  656M 19.3G 54.5G|   0     0 |   0     0 |3359  4272 |  0   0  99   0   0   0

3.1.5. pidstat

3.1.6. mpstat

mpstat 1 5

Linux 3.2.0-3-amd64 (xxxx.hostname) 05/18/2013 _x86_64_ (24 CPU)

12:13:38 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle

12:13:39 PM all 5.26 0.00 0.79 0.00 0.00 0.13 0.00 0.00 93.82

12:13:40 PM all 4.92 0.00 0.75 0.00 0.00 0.21 0.00 0.00 94.12

12:13:41 PM all 4.64 0.00 0.59 0.00 0.00 0.17 0.00 0.00 94.60

12:13:42 PM all 4.92 0.00 0.54 0.00 0.00 0.04 0.00 0.00 94.49

12:13:43 PM all 5.48 0.00 1.00 0.00 0.00 0.17 0.00 0.00 93.35

Average: all 5.05 0.00 0.74 0.00 0.00 0.14 0.00 0.00 94.08

CPU Processor number. The keyword all indicates that statistics are calculated as averages among all processors.

%usr Show the percentage of CPU utilization that occurred while executing at the user level (application).

%nice Show the percentage of CPU utilization that occurred while executing at the user level with nice priority.

%sys Show the percentage of CPU utilization that occurred while executing at the system level (kernel).

%iowait Show the percentage of time that the CPU or CPUs were idle during which the system had an outstanding disk I/O request.

%irq Show the percentage of time spent by the CPU or CPUs to service hardware interrupts.

%soft Show the percentage of time spent by the CPU or CPUs to service software interrupts.

%steal Show the percentage of time spent in involuntary wait by the virtual CPU or CPUs while the hypervisor was servicing another virtual processor.

%guest Show the percentage of time spent by the CPU or CPUs to run a virtual processor.

%idle Show the percentage of time that the CPU or CPUs were idle and the system did not have an outstanding disk I/O request.

mpstat -P ALL 1 5

查看单个CPU占用

3.2. 进程

3.2.1. 状态

3.2.2. ps

ps aux
ps auxf
ps -ef

3.2.3. top

3.2.4. lsof

lsof -p pid

4. 网络

4.1. 网卡状态

erhtool
```
ethtool eth0
```
mii-tool
```
mii-tool eth0
```
ip link
```
ip link show
```

4.2. 网卡流量

sar -n DEV 1 1000
bmon
iptraf
dstat --net-packets -n
iftop

4.3. 网络配置

4.3.1. ip

/etc/network/interfaces
ip address
ifconfig
curl ifconfig.me

4.3.2. route

ip route
netstat -rn
route -n

4.4. 防火墙

shorewall
iptables

4.5. 调试工具

lsof
telnet
nc
netstat
tcpdump/wireshark
nmap
tc

5. 文件系统和磁盘IO

5.1. 了解ext3，ext4，xfs，swap

ext3
```
mkfs.ext3

mkfs.ext3 -U uuid
```
ext4
```
mkfs.ext4

mkfs.ext4 -U uuid
```
xfs
```
mkfs.xfs

xfs_admin uuid
```
swap
```
mkswap

dd文件swap

swap分区
```

5.2. 会使用文件系统调试工具

fsck
```
fsck.ext3

fsck.ext4

fsck.xfs
```

5.3. 熟悉iostat，iotop

iostat
```
iostat -x 1 10

iostat -k 1 10
```
iotop
查看iowait
```
iostat -x 1 10

mpstat 1 10
```

5.4. 了解目录挂载，磁盘挂载，阅读fstab

mount
```
mount -a

umount

umount -l
```

fstab

UUID=uuid  /file ext3/ext4/xfs  noatime 0 0

内存文件系统挂载

mount -t tmpfs -o nosuid,nodev,size=10G,mode=1777 tmpfs /mnt/

移动硬盘挂载

mount -t ntfs -o uid=tom,gid=tom,fmask=133,dmask=022 /dev/sdz1 /mnt/usb/

blkid

/dev/sda1: UUID="b2bd9f7a-986c-4ee7-bc05-4cf43a896663" TYPE="ext3"

/dev/sda5: UUID="ff6117cf-5f8f-4b03-abcf-e784849a30eb" TYPE="swap"

/dev/sda6: LABEL="var" UUID="a0a59083-abb4-40e8-a7d6-b635e0db5d46" TYPE="ext3"

/dev/sda7: LABEL="tmp" UUID="1aa5f9c8-524a-4e69-b16b-2bfbc46bd948" TYPE="ext3"

/dev/sda8: LABEL="home" UUID="73cd148c-321b-4301-b099-8e0d1b1521b3" TYPE="ext4"

5.5. 增减swap

swapon
swapoff

禁用swap

echo 0 >/proc/sys/vm/swappiness

/etc/sysctl.conf && sysctl -p

sysctl -a|grep swappiness

5.6. 查看文件占用空间

du -sh
du -sh *

5.7. 查看文件系统占用空间

df -h
df -Th
df -ih

5.8. 查找进程打开的文件

fuser
```
fuser -mv /file
```
lsof
```
lsof -i:port

lsof /file
```

5.9. raid管理

5.9.1. LSI MeggaSAS

megacli

5.9.2. Adaptec

arcconf

6. Troubleshooting

6.1. dmesg

6.2. vmstat

6.3. top/iostat/free

6.4. last/lastlog

6.5. log

/var/log/auth.log

/var/log/user.log

/var/log/messages

6.6. shell

chsh -s /bin/bash user
bashrc
export
jdk

update-java-alternatives -s java-6-sun

6.7. 经验

7. 在线资源调整

7.1. /etc/sysctl.conf

7.2. /etc/sysfs.conf

7.3. sysctl

sysctl -a

sysctl -q

7.4. /proc

7.5. /sys

8. 其他

8.1. 1. 基本命令

awk
sed
find
grep/egrep

8.2. 2. 配置管理

8.3. 3. 窗口管理

tmux
screen