On 8 20 , 10 56 , LarryBoy <larry.tay...@co.travis.tx.us> wrote:
> ok when a page out wether its a pageout or a paging space page pout
> occurs the LRUD daemon finds
> a page in memory not least recently use so it frees it!! what do you
> mean 'frees it' ? Well, if the page was a computational page
> then LRUD forces it to be written to paging space so this is a paging
> space pageout. If the page is a file that has been read into memory
> then it writes it to disk IF the file changed otherwise it just gives
> the page to another process to overwrite.
> A paging space page in indicates that a computational page (part of a
> process) has been requested by another process and is read off of
> paging space into memory. The other page in indicates a file was
> requested from a process so it was read from a filesystem into memory.
> That vmstat -s data might be 'normal' but only you as a system admin
> of that particular system can answer that question.
> On AIX systems that run databases you do wantto do virtual memory
> tuning so that very little paging space is used.
> But on the same well-tuned Database system ytou might see many page in
> and page outs because different files are being accessed all the
> time.
> hope that this helps a little .....
Thank.
Base on below information, why tends to set pi and po to zero value ?
http://www-03.ibm.com/servers/enable...66/page_4.html
It is seem that our machine is not memory-bound, It seem that is cpu-
bound(cpu id time is small)
vmstat -t 1 10
System Configuration: lcpu=3 mem=6689MB
kthr memory page faults cpu
time
----- ----------- ------------------------ ------------ -----------
--------
r b avm fre re pi po fr sr cy in sy cs us sy id wa hr
mi se
3 3 1032198 371 0 0 0 628 569 0 1216 13997 1447 45 7 38
10 09:00:46
14 8 1032255 370 0 0 0 1592 4349 0 2803 25605 4391 65 17 1
17 09:00:47
13 5 1032380 381 0 0 0 1657 4453 0 2751 26284 4350 49 20 1
30 09:00:48
0 12 1032562 486 0 0 0 1915 5115 0 2975 25642 4895 56 19 0
25 09:00:49
12 5 1032585 366 0 0 0 1416 3799 0 2731 22188 4359 51 18 2
29 09:00:50
6 12 1032576 376 0 0 0 1607 5128 0 3049 20635 4449 61 15 0
24 09:00:51
11 12 1033033 385 0 0 0 1926 25340 1 2760 55272 4007 59 23
4 14 09:00:52
8 13 1032485 554 0 0 0 1045 8906 0 2766 24047 3997 68 19 0
13 09:00:53
10 6 1032544 366 0 0 0 1398 115324 0 2759 23395 4178 71 15
0 14 09:00:54
4 15 1032518 450 0 0 0 1667 7211 0 2821 22323 4386 68 19 1
11 09:00:55
Check by "ps -e -o pid,ppid,pcpu,cpu,etime,time,vsz,user,rssize,comm" .
One of process take about 22% CPU.
PID PPID %CPU CP ELAPSED TIME VSZ
USER RSS COMMAND
1753166 1 22.0 78 05:22:40 03:33:04 24280
root 24412 _sqlsrv2
2785318 1 12.6 30 32:46 00:12:22 1368 phx
6300 _progres
3121200 1 7.1 19 02:27:45 00:31:28 2232 phx
7164 _progres