Linux??????????

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Linux??????????
???? 2009?6?21?
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????

• ???,??????
• IXPUB ?????????? Linux????????
• ??oracle? Unix/Linux??,???????ITPUB.net?IXPUB.net?
  ChinaUnix.net???????,?????oracle????Unix/Linux????
  ???????,??????oracle??????????????,??oracle???????
  ?,????,?Unix/Linux????????????
•  
• ????????????
• MSNgaojf_888_at_hotmail.com
• QQ397824870
• Emaildba.gao_at_gmail.com

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Linux??????????

• ??Linux?????
• ????????
• ????????
• ?????????
• Oracle?Linux??????

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? ??Linux????????

• ?????

• CPU
• ??
• ??I/O??
• ??I/O??

• ?????

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? ????????
?????? ???? ???? ????
?????? ? ? ??
CPU user syslt 70 user sys 85 user sys gt90
?? Swap In(si)0 Swap Out(so)0 Per CPU with 10 page/s More Swap In Swap Out
?? iowait lt 20 iowait 35 iowait gt 50
?? user??CPU?????????????? sys??CPU????????
?????? iowait??CPU??????????????? swap
in?si,??????????,??SWAP DISK???RAM swap
out?so,??????????,??RAM???SWAP DISK?
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? ????????
??????
Vmstat?sar?iostat?netstat?free?ps?top?
??????

• ?vmstat?sar?iostat?????CPU??
• ?free?vmstat?????????
• ?iostat???????I/O??
• ?netstat???????????

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? Linux???????
1????????(uptime??)
root_at_web1 uptime 163800 up 118 days,
301, 5 users, load average 1.22, 1.02, 0.91
????????load average?????,???????????????CPU??
?,??,???????8?CPU,??load average????????8?,??CPU??
?,????,?????????,??????8?,?????,?????????????,??lo
ad average??????CPU???,???CPU????????,????????,CPU
???????
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2cpu????

• (1)??vmstat??????CPU
• ??????????????????????????,??????????CPU???????
  
• ???vmstat????????????
• root_at_node1 vmstat 2 3
• 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 0 162240 8304 67032 0 0 13
  21 1007 23 0 1 98 0 0
• 0 0 0 162240 8304 67032 0 0 1
  0 1010 20 0 1 100 0 0
• 0 0 0 162240 8304 67032 0 0 1
  1 1009 18 0 1 99 0 0
• Procs
• r????????cpu???????,???????????CPU???,??CPU??,???
  ?CPU?
• b????????????,??????I/O?????????
• Cpu
• us???????????CPU ??????us??????,?????????cpu???,?
  ???????50,?????????????
• sy???????????CPU??????Sy?????,???????CPU?????
• ????,ussy?????80,??ussy?? 80??????CPU?????

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(2) ??sar??????CPU

• sar?????,?????????????????,????sar?????????,??????
  ??????,????????????????
• ???sar????????CPU????
• root_at_webserver sar -u 3 5
• Linux 2.6.9-42.ELsmp (webserver)
  11/28/2008 _i686_ (8 CPU)
• 114124 AM CPU user nice system
  iowait steal idle
• 114127 AM all 0.88 0.00 0.29
  0.00 0.00 98.83
• 114130 AM all 0.13 0.00 0.17
  0.21 0.00 99.50
• 114133 AM all 0.04 0.00 0.04
  0.00 0.00 99.92
• 114136 AM all 90.08 0.00 0.13
  0.16 0.00 9.63
• 114139 AM all 0.38 0.00 0.17
  0.04 0.00 99.41
• Average all 0.34 0.00 0.16
  0.05 0.00 99.45
• ????????????
• user???????????CPU ??????
• nice??????????????CPU ??????
• system???????????CPU??????
• iowait????IO??????CPU?????
• steal???????????????pagein???????????steal?? ?

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???
????????CPU???????,?????????
????CPU????,??????????,?????????,CPU????????,?????
??????,????????????????,????????CPU,????CPU????100
,????????,????CPU???,???????CPU?????,???????????
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3??????
(1)??free?????? free???linux????????????,????????
root_at_webserver free -m
total used free shared
buffers cached Mem 8111 7185
926 0 243 6299 -/
buffers/cache 643 7468 Swap
8189 0 8189
???????????????????/??????gt70?,????????????,????
???,????????/??????lt20?,??????????,????????,20lt?
???????/??????lt70?,?????????????????,??????????
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(2) ??vmstat??????

• root_at_node1 vmstat 2 3
• 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 0 162240 8304 67032 0 0 13
  21 1007 23 0 1 98 0 0
• 0 0 0 162240 8304 67032 0 0 1
  0 1010 20 0 1 100 0 0
• 0 0 0 162240 8304 67032 0 0 1
  1 1009 18 0 1 99 0 0
• memory
• swpd????????????????(?k???)???swpd????0,?????,??s
  i?so?????0,???????????,?????????
• free??????????????(?k???)
• buff???buffers cache?????,???????????????
• cache???page cached?????,????????cached,?????????
  ?cached,??cache???,??cached??????,????IO?bi???,???
  ?????????
• swap
• si??????????,????????????????
• so??????????,????????????????
• ?????,si?so????0,??si?so??????0,??????????????????
  ?

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4??I/O????

• (1)??????
• ??RAID????,?????????,?????RAID???
• ???????????????I/O,??????????????????????,???
  ????????????????????
• ??????????????????????,??????????????
• ??????????,????????????????
• ?????????
• ????????,?????????????,???????,??????????
• ?????????????,??????????????I-node??
• ????????cache????,???I/O???
• ?????????
• ????????????,???????????

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• (2)??iostat??????
• root_at_webserver iostat -d 2 3
• Linux 2.6.9-42.ELsmp (webserver)
  12/01/2008 _i686_ (8 CPU)
•  
• Device tps Blk_read/s Blk_wrtn/s
  Blk_read Blk_wrtn
• sda 1.87 2.58 114.12
  6479462 286537372
•  
• Device tps Blk_read/s Blk_wrtn/s
  Blk_read Blk_wrtn
• sda 0.00 0.00 0.00
  0 0
•  
• Device tps Blk_read/s Blk_wrtn/s
  Blk_read Blk_wrtn
• sda 1.00 0.00 12.00
  0 24
• ????????????
• Blk_read/s????????????
• Blk_wrtn/s????????????
• Blk_read??????????
• Blk_wrtn??????????

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(3)??sar?????? ??sar
d??,????????IO????????,????????? root_at_webserv
er sar -d 2 3 Linux 2.6.9-42.ELsmp
(webserver) 11/30/2008 _i686_ (8
CPU)   110933 PM DEV tps rd_sec/s
wr_sec/s avgrq-sz avgqu-sz await svctm
util 110935 PM dev8-0 0.00 0.00
0.00 0.00 0.00 0.00
0.00 0.00   110935 PM DEV tps
rd_sec/s wr_sec/s avgrq-sz avgqu-sz await
svctm util 110937 PM dev8-0 1.00 0.00
12.00 12.00 0.00 0.00
0.00 0.00   110937 PM DEV tps
rd_sec/s wr_sec/s avgrq-sz avgqu-sz await
svctm util 110939 PM dev8-0 1.99 0.00
47.76 24.00 0.00 0.50
0.25 0.05   Average DEV tps
rd_sec/s wr_sec/s avgrq-sz avgqu-sz await
svctm util Average dev8-0 1.00 0.00
19.97 20.00 0.00
0.33 0.17 0.02 ??????????? await??
??????I/O???????(??????)? svctm????????I/O???????
(??????)? util???????????????I/O???
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(3)??sar?????? ????IO??,????????? ?????svctm??
???await??,?svctm??????????,CPU?????????svctm?????
,????????????svctm????? await?????????svctm???I/O
??????I/O????,??svctm???await???,??????I/O??,?????
?,??await?????svctm??,???I/O??????,?????????????,?
?????????????????? util?????????I/O???????,??ut
il??100,???????I/O????,I/O???????????,???????????
???,?????????,?????????????????????????????
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5??????
(1)??ping?????????? (2)??netstat
i?????????? (3)??netstat r???????????? (4)??sa
r n?????????????
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? Oracle?Linux??????

• Oracle??????????
• ?oracle?????????
• SGA?PGA????
• Oracle?????????
• ???????(ext2/ext3?xfs?ocfs2)
• Oracle ASM??

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1??oracle???????????
1)?????? 2)?????????????? 3)??????????????? 4)
??????? 5)???OLTP ????OLAP ??
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2Oracle??????????
(1)?????? ?? /etc/sysctl.conf
????,??????? kernel.shmmax 2147483648 kernel.s
hmmni 4096 kernel.shmall 2097152 kernel.sem
250 32000 100 128 fs.file-max
65536 net.ipv4.ip_local_port_range 1024
65000 ????? Kernel.shmmax??????????(??????)? Ke
rnel.shmmni?????????????? Kernel.shmall??????,??
???? fs.file-max?????,???Linux????????????? net.i
pv4.ip_local_port_range????????IPv4?????
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?????????
??Kernel.shmmax Oracle SGA ???????,??????
SHMMAX?????SGA ???,SHMMAX?????????????ORA-27123u
nable to attach to shared memory
segment,?????????Oracle SGA??,??SGA???????????????
??????????????,??????? Oracle??Kernel.shmmax????s
ga,??oracle?????SGA?????????,??????? ??Kernel.shm
all ???????????,?????? ??32??Linux??,8G???,????
kernel.shmall 2097152,?? 20971524k/1024/1024
8G ??????????? 8G,???4K?32??????????,?4096??? ?
?Kernel.shmmni ?????????????????????4096,??????,
?SUN OS???Kernel.shmmin??,???????????,????!
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(2)SGA?PAG????

• Oracle??????????
• Oracle 9i????PGA_AGGREGATE_TARGET????PGA???? Orac
  le 10g????SGA_TARGET?????SGA?????,
• Oracle 11g??????????????????,??????SGA?PGA?????
• ???????????
• MEMORY_TARGET????ORACLE???????????,??PGA?SGA????
  ?,?????????,??????SGA?PGA????
• MEMORY_MAX_TARGET???????MEMORY_TARGET???????????
  ????,??????MEMORY_MAX_TARGET?,????MEMORY_TARGET???
  
• ?????????,SGA_TARGET?PGA_AGGREGATE_TARGET????????
  ???????,??Oracle????????,??????????0?

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B. Oracle????????

• ??????,?AMM (Automatic Memory Management)
• ????????,?ASMM(Automatic Shared Memory
  Management)
• ????????
• ??PGA??
• ??PGA??

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??????(AMM)
????oracle11g?????AMM????????? ???? SQLgt show
parameters target NAME
TYPE
VALUE------------ ---------------------
------------------ ----------------------
archive_lag_target integer
0db_flashback_retention_target
integer 1860fast_start_io_t
arget integer
0fast_start_mttr_target
integer 0memory_max_target
big integer
1400Mmemory_target big
integer 1400Mpga_aggregate_target
big integer
0sga_target big
integer 0 ????????? LOCK_SGA
true ,? AMM ??????
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????????
?????????oracle10g???,?????????????,????MEMORY_TAR
GET0,??????SGA_TARGET??? ???? SQLgt alter
system set memory_target0 scopebothSystem
altered.SQLgt alter system set sga_target1024m
scopebothSystem altered.SQLgt
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????????
Oracle9i??????,????????????,?????????????,??????SG
A_TARGET ? MEMORY_TARGET?0? SGA??????? share_po
ol_size?????,??300-500M??? Log_buffer???????,??1
-3M??? Large_pool_size??????,?MTS??,???20-30M???
Java_pool_sizejava???,??java???,??10-20M??? db_ca
che_size???????,?????????,?????
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??PAG??
Oracle9i???????PGA??,??????AMM????,?????PGA???,???
???AMM???????,??????PGA??,?? WORKAREA_SIZE_POLICY
AUTO ????PGA_AGGREGATE_TARGET?????,
??PAG??
??????????PGA,?????????PGA,?? WORKAREA_SIZE_POLICY
manual ??????PGA?????? PGA????? SORT_AREA_SI
ZE SORT_AREA_RETAINED_SIZE,
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3Oracle?????????

• ??????????
• ???????
• ??????(ext2?ext3?xfs?)
• ??????(gfs?ocfs2)
• ?????????
• ?????????
• ?????????????????,???????
• ASM(Automatic Storage Management)
• ASM??
• ???????,??????????????,?????????????????
• Oracle?????????????

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????