Mount the file system that holds your temporary tablespace in Direct mode
(non-buffered mode) and try to find if AIX has something similar to the
priority paging in Solaris.

Also Raw partitions are good  at least (in your case) for temporary
tablespace.

Also check if your tablespace is defined as temporary.

Regards,

Waleed

-----Original Message-----
Sent: Thursday, December 20, 2001 6:10 PM
To: Multiple recipients of list ORACLE-L


I am resolved that the trouble is not enough swap and not enough aio
processes.  I think this will significantly improve the system.  Spreading
swap will be my next push if I still have trouble.  vmtune will be last
which is basically what I wanted to confirm.

AIX vmstat shows

kthr     memory             page              faults        cpu
----- ----------- ------------------------ ------------ -----------
 r  b   avm   fre  re  pi  po  fr   sr  cy  in   sy  cs us sy id wa
 0  0 522715  4737   0   1   1  39  115   0 147  440 151  3  1 92  3
 0  2 522715  4646   0   0   0   0    0   0 522 1169 133  3  4 91  2
 0  2 522715  4646   0   0   0   0    0   0 472  564  60  0  0 99  0

However topas shows more info about where the pageing is occuring i.e.
good/normal paging as oposed to bad paging as seen below.  PgspIn and
PgspOut are the bad kind.

Topas Monitor for host:    FOO                  EVENTS/QUEUES    FILE/TTY
Thu Dec 20 18:10:02 2001   Interval:  2         Cswitch    2625  Readch
11505467
                                                Syscall   40623  Writech
883896
Kernel   42.7   |############                |  Reads      5506  Rawin
0
User     13.1   |####                        |  Writes      514  Ttyout
318
Wait      9.3   |###                         |  Forks       179  Igets
9
Idle     34.7   |##########                  |  Execs       177  Namei
6369
                                                Runqueue    7.5  Dirblk
49
Interf   KBPS   I-Pack  O-Pack   KB-In  KB-Out  Waitqueue   2.0
en1        9.4    25.9    16.9     3.1     6.3
en0        1.4    10.9     3.9     0.9     0.5  PAGING           MEMORY
                                                Faults    30366  Real,MB
4095
Disk    Busy%     KBPS     TPS KB-Read KB-Writ  Steals        0  % Comp
39.2
hdisk0   47.4    574.7    92.3     9.9   564.8  PgspIn        2  % Noncomp
61.4
hdisk1   41.9    572.8    89.8     0.0   572.8  PgspOut       0  % Client
348
hdisk3    1.4    337.3    10.4     0.0   337.3  PageIn     66 2
0992
hdisk10   0.0      0.0     0.0     0.0     0.0  PageOut     229  PAGING
SPACE
hdisk4    0.0      3.9     0.4     0.0     3.9  Sios        118  Size,MB
2992
                                                                 % Used
22.3
dm_ep_eng(11094) 12.5% PgSp: 1.0mb root                          % Free
77.6
init     (1)      6.0% PgSp: 0.6mb root
ksh      (35124)  5.0% PgSp: 0.3mb oracle
ksh      (15854)  4.00    10.0.4mb oracle    4     Press "h" for help
screen.
ksh      (68298)  4.05 PgSp: 0.3mb oracle    5     Press "q" to quit
program.
sadc     (59690)  3.0% PgSp: 0.1mb root
ksh      (53722)  3.0% PgSp: 0.3mb oracle
ksh      (63038)  2.0% PgSp: 0.3mb oracle
ksh      (27478)  2.0% PgSp: 0.3mb oracle
ksh      (61336)  2.0% PgSp: 0.3mb oracle

-----Original Message-----
Sent: Thursday, December 20, 2001 3:40 PM
To: Multiple recipients of list ORACLE-L


Ethan,

AIX performs all file i/o via the OS's virtual memory. In other words, the
VM (which is a combination of both the RAM and the Swap) is used for both
executable (OS/user code) and user's memory area as well as for I/O buffers.
This allocation is dynamic and certain upper and lower limits are set by the
parameters in vmtune. At times of high i/o, you will find that the 'fre' mem
(seen in vmstat' goes down drastically and the po/fr/sr goes up drastically
as a result of old memory pages that served file i/o buffers are paged out.
This is normal and in line with what you are observing and is similar to
Solaris. 

What you *should* be concerned about is excessive values in 'pi' as this
indicates excessive paging-*in*, probably due to earlier pageouts of live
pages that are still required. You are probably seeing high I/o waits since
there is a lot of writes (paging out) to the swap area. 'iostat' will
probably indicate that disks that host your swap area are almost 100%
loaded. In this case, you should make sure that you (a) spread out swap on
multiple disks, making sure that they are NOT on RAID-5. (b) allocate
dedicated drives to swap areas if possible (no RAID5!).

FWIW, vmstat in Solaris is able to distinguish between pi/po values for
executable, file i/o and 'other' (?) types of paging. Can you find out for
us if AIX also provides this? (Don't have access to an AIX box).

Merry Christmas and a Blessed New Year!

John Kanagaraj
Oracle Applications DBA
DBSoft Inc
(W): 408-970-7002

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