網絡依然還是計算機,Sun還是Sun！
Solaris 内存Troubleshooting和调优
上一篇 / 下一篇 2007-08-26 18:39:42 / 个人分类：Solaris學習
查看( 198 ) /
评论( 1 )
Solaris Memory Troubleshooting and Tuning
\bn(AT6a0 Author: John RichardsonIXPUB技术博客7U Q _i0}^ v B
Source: http://www.sunhelpdesk.com
O {.a/k2U0
(j@5JtCM y&J0 IXPUB技术博客Z y(I] I#@)]'T'{g
Before We Begin
0x'h@1Ay"U2R0
~R+C k?!E0 The first thing to be aware of is that Solaris utilizes almost all of physical memory on a system. The output of vmstat shows very little memory free no mater what is happening on the server. This is because it will cache portions of the file system in memory for quicker access. This makes sense because you would rather be using your memory than letting it collect dust if your applications/processes are not using it. For instance, if you continually open a file from an application, chances are it will be in memory the next time you access it. This greatly improves I/O performance because RAM access is many times faster than accessing the data from disk.
(c{H{Z0 IXPUB技术博客&~ ] \0y9u
As with is the case most often, you need the right tools to effectively solve problems. I prefer to use “memtool” as my primary tool to solve memory problems. Memtool functions are being integrated into Solaris 8 and 9. However, currently I suggest utilizing memtool as it provides a wide range of useful tools compatible with most Solaris versions. You can download the latest version from:IXPUB技术博客 ^"j&zn&?#Es@
;Q,Ur i3]5y0 • http://www.solarisinternals.com/si/downloads/_memtool/
+O(D?7P)mTI0 IXPUB技术博客ZH!UtJ
)FGi0|TJP-M3s T0 Identifying a Memory Problem
G[;s o.d `0 IXPUB技术博客3I5g"o,nN;y+B)[ g
The following methods can be used to identify a memory problem:
%p0~"a T mo7Z0 IXPUB技术博客i:h O u2Hl;z)l
Check scan rate(sr) using vmstat:
i:Q t#O5[ F"UX0 IXPUB技术博客 yH6k#p,p(g
• Look at the “sr” column of vmstat over a 30 second period to get an average scan rate. If values are consistently non-zero, then there is a possibility of a memory shortage problem. IXPUB技术博客)W"]2y!N$v
B*XW2b to`go1~0 Important: A common misconception is that an average non-zero scan rate (especially above 200) indicates a memory shortage. There is the same probability that a non-zero scan rate indicates file system paging instead of application paging. Unfortunately, the Solaris memory system (vmstat) counts paging activity generated by both file system paging and application paging. So, if your system is paging in and out file I/O, then the (pi) and (po) columns of vmstat will show this activity along with an increasing scan rate (if number of free pages falls below lotsfree). An important fact to point out here is that the system will not use swap space to handle unmodified file pages as it does with application paging. File pages are not required to be in memory at all times as is the case with application memory. Therefore, if you run out of application memory, the system is forced to page in and out to the swap device causing horrible performance. For instance, consider a system with plenty of physical memory with a large portion being utilized for file system buffer cache (Think of the buffer cache as a portion of memory being utilized to store data reads from disk so that it can be processed). The data is left in RAM in hopes that the process will need this data again in the future and not have to access the slow disk again. If there is a lot of random I/O (not sequential because of the “free behind and read ahead” memory policy), the scanner daemon may be invoked to find available memory pages in the file system buffer cache, thus increasing the scan rate (I have witnessed scan rates over 10000 on Solaris 7 due to high random file i/o). Note that in this case, application memory is not low, rather the file buffer cache has used all of the free pages. Therefore, the scan rates may be high only because it is looking for free pages for file system buffer cache, and not due to swapping pages in and out of virtual memory. You can verify this by looking at the results of “prtmem” (will discuss prtmem later) to see if file system buffer cache is still high (above 10% of total memory), as well as checking there is no disk i/o activity on the swap device. IXPUB技术博客\{3Rf ZU
IXPUB技术博客5W+J*Ddxg7g#d*n
Therefore, you cannot use vmstat in isolation to determine a memory shortage. Although vmstat will indeed show that the system is not low on memory (no paging or scanning), it does not definitively indicate a memory shortage. You should combine vmstat with the use one of the following two methods.
4l9@:l:R&B0C0X"F)p#R X&A0
S~7Z'sciNq2a0 Monitor the disk activity of the swap partition (device):IXPUB技术博客1?(x'bA D%h+[
"|h zz e0 • Take a look at the output of “iostat -xPnc 5” to determine if there is any significant I/O on the swap device. This is a true indication of swapping (memory shortage). The following example output of the swap partition indicates there is no memory problem (notice all zeros):
/` Ap7C-J s4lY N0
J ?$`{v d W(M yt.ku0 r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b deviceIXPUB技术博客 T e p'q I$}5uKUf
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c0t0d0s2 IXPUB技术博客&H d+Syp_s
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c0t0d0s2
[!v r*qmp wU.Vg0 …
l tO-?*Nw Q8? M0 IXPUB技术博客Z6X-B M e b+Mf
A quick command check if you know the swap device (usually slice 2 of the boot disk) is “iostat -xPnc 5 | grep c0t0d0s2”. Watch the output to see if there is any activity.IXPUB技术博客6b%X&}-b|&Z;H7l
IXPUB技术博客7lNw^9hd? Y#K
Use memtool (this is my favorite option as it provides a lot of detail):IXPUB技术博客M&aRv ? ]i
IXPUB技术博客Tz:^kJ L3Y `s
• Memtool is a great resource to show memory distribution in a system. In particular, if the file system buffer cache is less than 10% of total memory, then there is a memory shortage.
-H F G?-v&^0
v(qa w#EQ:?0
^|;yzrc+tPc0 Using Memtool to Investigate Memory
-Q3d"U4UN mDX?0 IXPUB技术博客G x*F$T!P
Memtool is excellent resource in determining memory distribution of a system. Here is an example of the prtmem command provided with memtool:
R)cc X M i9B @]4i] V0 IXPUB技术博客6t e L!nX7a3Vi
# prtmem
:\8K-k B s"f"E0 IXPUB技术博客}_(f0b3{XY
Total memory: 5875 Megabytes
k5?:[%ci0 Kernel Memory: 485 Megabytes
+u rTg,h+a[0T0 Application: 2007 MegabytesIXPUB技术博客!feb[.g-VM,Sk9d
Executable & libs: 154 Megabytes
Q v j(M_&Y{ F0 File Cache: 3043 MegabytesIXPUB技术博客,Pje&i7Ee z'C
Free, file cache: 172 Megabytes
4z's5c(Cv;}U;M0 Free, free: 12 Megabytes
0XBM8T%Q7@C%N ?0 IXPUB技术博客!b,G SN1Ic
Pay close attention to File Cache, Free file cache, and Free output lines. This indicates how much memory is being used by file system cache and how much memory is not being used by the system at all. The total of these three lines should be more than 10% of the total memory of a system. If it drops below 10% of total memory, the scanner daemon will likely be invoked to find free pages in memory for applications. This will cause the system to swap and cause poor performance. This will be indicated by high (pi), (po), and (sr) columns in vmstat output as well as queued disk activity on the swap device. Note that prtmem includes shared memory in the Application output line above. As you can see, a quick look at the memory distribution of a system using prtmem can quickly determine if there is a memory problem on a system.
xJnlO/y Gg I0 IXPUB技术博客;N:P6@.d$Y.y
If application memory is causing a memory shortage, you may be interested in finding the application that is using the most memory. The memps command shows how much memory processes (as well as file system with -m argument) are using.
/Ey'mw4lvh S!U(t0
&e t5vjCRC,N8V0 # memps
)D*yof!^H|_0
%Ed\.p#r8Vz0 PID Size Resident Shared Anon Process
r6Hk1iE$m9ma4K8q D0 873 14144k 7224k 1728k 5496k /opt/VRTSvmsa/jre/bin/../bin/sparc/native_threads/jre
? WTgZ4Q0 933 16160k 4872k 2096k 2776k /opt/perf/bin/scopeuxIXPUB技术博客OprZDG{U(DU
865 10152k 3480k 1552k 1928k /opt/VRTSvmsa/jre/bin/../bin/sparc/native_threads/jre IXPUB技术博客U w$mu7Z x/E
1605 13344k 5816k 4808k 1008k opcmsga
6\'p2D?Pc0 1608 11512k 5600k 4720k 880k opcmonaIXPUB技术博客p(nZS5M| J
1607 10832k 5528k 4656k 872k opcleIXPUB技术博客 aA`8l ?|
26545 3952k 2232k 1456k 776k /usr/sbin/nscd
C-J*XqW0h0 Notice that processes have anonymous and shared memory. The sum of this memory equals the resident size (total memory inclusive of shared memory and private memory) in memory. The size column displays the total virtual (physical and swap) memory assigned to this process. To estimate the total memory used by a group of the same processes, some calculation is required. Simply sum the anonymous memory of each process and add the largest shared memory size of the individual processes. We are only adding the shared memory size once because each process is using the same shared memory, so we don’t want to include this multiple times. If you want to know how much memory different processes are using, you will need to sum the shared memory of each process because the shared memory for each process is a different portion of physical ram and needs to be included.
#}M2r_Jw2daFK0 IXPUB技术博客Kb E;i C0[D4P+P/}/k
Here is an example of calculating the memory utilized by the same ksh processes:IXPUB技术博客 N[ Gx+|6p*L2I"G
Sfu!J'Zv;qX&Y6UGv0 # memps | grep kshIXPUB技术博客8?#Ys[~-r:l
14466 1824k 1552k 1376k 176k -kshIXPUB技术博客(J.}.[(EN
784 1816k 1504k 1408k 96k /bin/ksh /opt/VRTSvmsa/bin/vmsa_server
C;rqPo"EM0jC0 14320 1824k 1512k 1416k 96k -kshIXPUB技术博客 GD |#B^'R6VW6_ g
14102 1824k 1512k 1416k 96k -ksh
0e7\M {PL+k {0 27477 1832k 1512k 1416k 96k -kshIXPUB技术博客R'W&^g5B#r t!O W U
11150 1840k 1512k 1416k 96k -ksh
d;V P,MM0O3s-`0 6969 1832k 1512k 1416k 96k -kshIXPUB技术博客7h(m-Z2J K(d e
6220 1824k 1512k 1416k 96k -kshIXPUB技术博客"]P+W4NE:h v
--------------------------------------------------------------
*z\R3h9G;NV0 Total Anonymous = 848k
9B+{&} NCm.c7SS+FFA0 Max Shared Memory = 1416kIXPUB技术博客i `J Y&s PEz E
Memory Used Estimate = 2264kIXPUB技术博客 [[v4uj \E
;a%x4Z&Wh0 If you would like to dig deeper into an individual process, Memtool provides pmap which is equivalent to Solaris command “pmap”. Pmem shows the memory address space of an individual process. It basically shows a breakdown of the mapped files in memory for the process.IXPUB技术博客 F Ak$s9W }
5EH9B M Wxx O0
[]d R/W&tbP0 Finding Memory LeaksIXPUB技术博客3TMY'U"x S8kV `
$UZ'hzNu(n7p0 An application memory leak occurs when process memory continues to grow without bounds. This can be seen by looking at the private portion of resident memory with the pmem command. If it continually grows, there is likely a memory leak.
c0g1z T"Z0
Oy)L2e sav0 IXPUB技术博客gFD lL3lE+Hn
Memory Performance Tuning
2I8j [t hN0
&H'\+{ A!s4e0 The default configuration of many systems are usually not optimal settings given the range of memory requirements from diverse applications. There are system parameters that can be tweaked to provide better system performance in regards to memory utilization, especially for larger and faster systems available today. The following are general system parameters I tweak on new server systems to optimize memory performance in /etc/system:
"z0K m\\&KI0 IXPUB技术博客$nL-G:vB |@B
set priority_paging=1 ç Only if using Solaris 7 or 2.6
5S6W%M y0t,T(B^+X TO0 set fastscan=131072
%h/u1y | s0 set handspreadpages=131072IXPUB技术博客!N%N |!o}6s'w&k J.r9X-t+[
set maxpgio=65536
3]9q9us(D"v0
!jW7WM'x p f0 Enable priority paging if using Solaris 7 or Solaris 2.6 with patch 105181 applied. Priority paging ensures that file pages will be paged out before paging out application pages. Solaris 8 and above has a new third generation memory algorithm which handles this feature.
3D` ^*Iw0
:S](tBV+x0 Fastscan is maximum number of pages per second that the system looks at when memory pressure is highest. That is, it is the number of pages the scanner daemon tries to scan when invoked by free memory falling below lotsfree. The default is 8192. Handspreadpages should be set to the same size of fastscan. Keep in mind that fastscan and handspreadpages should be less than or equal to total physical memory / 4.IXPUB技术博客"|5f Q1n$e$c(m"J
IXPUB技术博客 _&{0Gx E&@+K.[4hc
Maxpgio is the maximum number of page I/O requests that can be queued by the paging system. This number is divided by 4 to get the actual maximum used by the paging system. It is used to throttle the number of requests as well as to control process swapping. There is really no harm in setting this value too large.
\bn(AT6a0 Author: John RichardsonIXPUB技术博客7U Q _i0}^ v B
Source: http://www.sunhelpdesk.com
O {.a/k2U0
(j@5JtCM y&J0 IXPUB技术博客Z y(I] I#@)]'T'{g
Before We Begin
0x'h@1Ay"U2R0
~R+C k?!E0 The first thing to be aware of is that Solaris utilizes almost all of physical memory on a system. The output of vmstat shows very little memory free no mater what is happening on the server. This is because it will cache portions of the file system in memory for quicker access. This makes sense because you would rather be using your memory than letting it collect dust if your applications/processes are not using it. For instance, if you continually open a file from an application, chances are it will be in memory the next time you access it. This greatly improves I/O performance because RAM access is many times faster than accessing the data from disk.
(c{H{Z0 IXPUB技术博客&~ ] \0y9u
As with is the case most often, you need the right tools to effectively solve problems. I prefer to use “memtool” as my primary tool to solve memory problems. Memtool functions are being integrated into Solaris 8 and 9. However, currently I suggest utilizing memtool as it provides a wide range of useful tools compatible with most Solaris versions. You can download the latest version from:IXPUB技术博客 ^"j&zn&?#Es@
;Q,Ur i3]5y0 • http://www.solarisinternals.com/si/downloads/_memtool/
+O(D?7P)mTI0 IXPUB技术博客ZH!UtJ
)FGi0|TJP-M3s T0 Identifying a Memory Problem
G[;s o.d `0 IXPUB技术博客3I5g"o,nN;y+B)[ g
The following methods can be used to identify a memory problem:
%p0~"a T mo7Z0 IXPUB技术博客i:h O u2Hl;z)l
Check scan rate(sr) using vmstat:
i:Q t#O5[ F"UX0 IXPUB技术博客 yH6k#p,p(g
• Look at the “sr” column of vmstat over a 30 second period to get an average scan rate. If values are consistently non-zero, then there is a possibility of a memory shortage problem. IXPUB技术博客)W"]2y!N$v
B*XW2b to`go1~0 Important: A common misconception is that an average non-zero scan rate (especially above 200) indicates a memory shortage. There is the same probability that a non-zero scan rate indicates file system paging instead of application paging. Unfortunately, the Solaris memory system (vmstat) counts paging activity generated by both file system paging and application paging. So, if your system is paging in and out file I/O, then the (pi) and (po) columns of vmstat will show this activity along with an increasing scan rate (if number of free pages falls below lotsfree). An important fact to point out here is that the system will not use swap space to handle unmodified file pages as it does with application paging. File pages are not required to be in memory at all times as is the case with application memory. Therefore, if you run out of application memory, the system is forced to page in and out to the swap device causing horrible performance. For instance, consider a system with plenty of physical memory with a large portion being utilized for file system buffer cache (Think of the buffer cache as a portion of memory being utilized to store data reads from disk so that it can be processed). The data is left in RAM in hopes that the process will need this data again in the future and not have to access the slow disk again. If there is a lot of random I/O (not sequential because of the “free behind and read ahead” memory policy), the scanner daemon may be invoked to find available memory pages in the file system buffer cache, thus increasing the scan rate (I have witnessed scan rates over 10000 on Solaris 7 due to high random file i/o). Note that in this case, application memory is not low, rather the file buffer cache has used all of the free pages. Therefore, the scan rates may be high only because it is looking for free pages for file system buffer cache, and not due to swapping pages in and out of virtual memory. You can verify this by looking at the results of “prtmem” (will discuss prtmem later) to see if file system buffer cache is still high (above 10% of total memory), as well as checking there is no disk i/o activity on the swap device. IXPUB技术博客\{3Rf ZU
IXPUB技术博客5W+J*Ddxg7g#d*n
Therefore, you cannot use vmstat in isolation to determine a memory shortage. Although vmstat will indeed show that the system is not low on memory (no paging or scanning), it does not definitively indicate a memory shortage. You should combine vmstat with the use one of the following two methods.
4l9@:l:R&B0C0X"F)p#R X&A0
S~7Z'sciNq2a0 Monitor the disk activity of the swap partition (device):IXPUB技术博客1?(x'bA D%h+[
"|h zz e0 • Take a look at the output of “iostat -xPnc 5” to determine if there is any significant I/O on the swap device. This is a true indication of swapping (memory shortage). The following example output of the swap partition indicates there is no memory problem (notice all zeros):
/` Ap7C-J s4lY N0
J ?$`{v d W(M yt.ku0 r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b deviceIXPUB技术博客 T e p'q I$}5uKUf
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c0t0d0s2 IXPUB技术博客&H d+Syp_s
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c0t0d0s2
[!v r*qmp wU.Vg0 …
l tO-?*Nw Q8? M0 IXPUB技术博客Z6X-B M e b+Mf
A quick command check if you know the swap device (usually slice 2 of the boot disk) is “iostat -xPnc 5 | grep c0t0d0s2”. Watch the output to see if there is any activity.IXPUB技术博客6b%X&}-b|&Z;H7l
IXPUB技术博客7lNw^9hd? Y#K
Use memtool (this is my favorite option as it provides a lot of detail):IXPUB技术博客M&aRv ? ]i
IXPUB技术博客Tz:^kJ L3Y `s
• Memtool is a great resource to show memory distribution in a system. In particular, if the file system buffer cache is less than 10% of total memory, then there is a memory shortage.
-H F G?-v&^0
v(qa w#EQ:?0
^|;yzrc+tPc0 Using Memtool to Investigate Memory
-Q3d"U4UN mDX?0 IXPUB技术博客G x*F$T!P
Memtool is excellent resource in determining memory distribution of a system. Here is an example of the prtmem command provided with memtool:
R)cc X M i9B @]4i] V0 IXPUB技术博客6t e L!nX7a3Vi
# prtmem
:\8K-k B s"f"E0 IXPUB技术博客}_(f0b3{XY
Total memory: 5875 Megabytes
k5?:[%ci0 Kernel Memory: 485 Megabytes
+u rTg,h+a[0T0 Application: 2007 MegabytesIXPUB技术博客!feb[.g-VM,Sk9d
Executable & libs: 154 Megabytes
Q v j(M_&Y{ F0 File Cache: 3043 MegabytesIXPUB技术博客,Pje&i7Ee z'C
Free, file cache: 172 Megabytes
4z's5c(Cv;}U;M0 Free, free: 12 Megabytes
0XBM8T%Q7@C%N ?0 IXPUB技术博客!b,G SN1Ic
Pay close attention to File Cache, Free file cache, and Free output lines. This indicates how much memory is being used by file system cache and how much memory is not being used by the system at all. The total of these three lines should be more than 10% of the total memory of a system. If it drops below 10% of total memory, the scanner daemon will likely be invoked to find free pages in memory for applications. This will cause the system to swap and cause poor performance. This will be indicated by high (pi), (po), and (sr) columns in vmstat output as well as queued disk activity on the swap device. Note that prtmem includes shared memory in the Application output line above. As you can see, a quick look at the memory distribution of a system using prtmem can quickly determine if there is a memory problem on a system.
xJnlO/y Gg I0 IXPUB技术博客;N:P6@.d$Y.y
If application memory is causing a memory shortage, you may be interested in finding the application that is using the most memory. The memps command shows how much memory processes (as well as file system with -m argument) are using.
/Ey'mw4lvh S!U(t0
&e t5vjCRC,N8V0 # memps
)D*yof!^H|_0
%Ed\.p#r8Vz0 PID Size Resident Shared Anon Process
r6Hk1iE$m9ma4K8q D0 873 14144k 7224k 1728k 5496k /opt/VRTSvmsa/jre/bin/../bin/sparc/native_threads/jre
? WTgZ4Q0 933 16160k 4872k 2096k 2776k /opt/perf/bin/scopeuxIXPUB技术博客OprZDG{U(DU
865 10152k 3480k 1552k 1928k /opt/VRTSvmsa/jre/bin/../bin/sparc/native_threads/jre IXPUB技术博客U w$mu7Z x/E
1605 13344k 5816k 4808k 1008k opcmsga
6\'p2D?Pc0 1608 11512k 5600k 4720k 880k opcmonaIXPUB技术博客p(nZS5M| J
1607 10832k 5528k 4656k 872k opcleIXPUB技术博客 aA`8l ?|
26545 3952k 2232k 1456k 776k /usr/sbin/nscd
C-J*XqW0h0 Notice that processes have anonymous and shared memory. The sum of this memory equals the resident size (total memory inclusive of shared memory and private memory) in memory. The size column displays the total virtual (physical and swap) memory assigned to this process. To estimate the total memory used by a group of the same processes, some calculation is required. Simply sum the anonymous memory of each process and add the largest shared memory size of the individual processes. We are only adding the shared memory size once because each process is using the same shared memory, so we don’t want to include this multiple times. If you want to know how much memory different processes are using, you will need to sum the shared memory of each process because the shared memory for each process is a different portion of physical ram and needs to be included.
#}M2r_Jw2daFK0 IXPUB技术博客Kb E;i C0[D4P+P/}/k
Here is an example of calculating the memory utilized by the same ksh processes:IXPUB技术博客 N[ Gx+|6p*L2I"G
Sfu!J'Zv;qX&Y6UGv0 # memps | grep kshIXPUB技术博客8?#Ys[~-r:l
14466 1824k 1552k 1376k 176k -kshIXPUB技术博客(J.}.[(EN
784 1816k 1504k 1408k 96k /bin/ksh /opt/VRTSvmsa/bin/vmsa_server
C;rqPo"EM0jC0 14320 1824k 1512k 1416k 96k -kshIXPUB技术博客 GD |#B^'R6VW6_ g
14102 1824k 1512k 1416k 96k -ksh
0e7\M {PL+k {0 27477 1832k 1512k 1416k 96k -kshIXPUB技术博客R'W&^g5B#r t!O W U
11150 1840k 1512k 1416k 96k -ksh
d;V P,MM0O3s-`0 6969 1832k 1512k 1416k 96k -kshIXPUB技术博客7h(m-Z2J K(d e
6220 1824k 1512k 1416k 96k -kshIXPUB技术博客"]P+W4NE:h v
--------------------------------------------------------------
*z\R3h9G;NV0 Total Anonymous = 848k
9B+{&} NCm.c7SS+FFA0 Max Shared Memory = 1416kIXPUB技术博客i `J Y&s PEz E
Memory Used Estimate = 2264kIXPUB技术博客 [[v4uj \E
;a%x4Z&Wh0 If you would like to dig deeper into an individual process, Memtool provides pmap which is equivalent to Solaris command “pmap”. Pmem shows the memory address space of an individual process. It basically shows a breakdown of the mapped files in memory for the process.IXPUB技术博客 F Ak$s9W }
5EH9B M Wxx O0
[]d R/W&tbP0 Finding Memory LeaksIXPUB技术博客3TMY'U"x S8kV `
$UZ'hzNu(n7p0 An application memory leak occurs when process memory continues to grow without bounds. This can be seen by looking at the private portion of resident memory with the pmem command. If it continually grows, there is likely a memory leak.
c0g1z T"Z0
Oy)L2e sav0 IXPUB技术博客gFD lL3lE+Hn
Memory Performance Tuning
2I8j [t hN0
&H'\+{ A!s4e0 The default configuration of many systems are usually not optimal settings given the range of memory requirements from diverse applications. There are system parameters that can be tweaked to provide better system performance in regards to memory utilization, especially for larger and faster systems available today. The following are general system parameters I tweak on new server systems to optimize memory performance in /etc/system:
"z0K m\\&KI0 IXPUB技术博客$nL-G:vB |@B
set priority_paging=1 ç Only if using Solaris 7 or 2.6
5S6W%M y0t,T(B^+X TO0 set fastscan=131072
%h/u1y | s0 set handspreadpages=131072IXPUB技术博客!N%N |!o}6s'w&k J.r9X-t+[
set maxpgio=65536
3]9q9us(D"v0
!jW7WM'x p f0 Enable priority paging if using Solaris 7 or Solaris 2.6 with patch 105181 applied. Priority paging ensures that file pages will be paged out before paging out application pages. Solaris 8 and above has a new third generation memory algorithm which handles this feature.
3D` ^*Iw0
:S](tBV+x0 Fastscan is maximum number of pages per second that the system looks at when memory pressure is highest. That is, it is the number of pages the scanner daemon tries to scan when invoked by free memory falling below lotsfree. The default is 8192. Handspreadpages should be set to the same size of fastscan. Keep in mind that fastscan and handspreadpages should be less than or equal to total physical memory / 4.IXPUB技术博客"|5f Q1n$e$c(m"J
IXPUB技术博客 _&{0Gx E&@+K.[4hc
Maxpgio is the maximum number of page I/O requests that can be queued by the paging system. This number is divided by 4 to get the actual maximum used by the paging system. It is used to throttle the number of requests as well as to control process swapping. There is really no harm in setting this value too large.
TAG:
-
云杉上的蝴蝶
发布于2007-09-05 16:30:37
-
此帖已收集到主题列表
