Performance problem.

Hi partners,

We have upgraded one Ebusiness environment from 11.0.3 to 11.5.10.2, also
we moved from HPUX to AIX, after that we are having some performance
issues on this new platform.

We have gathered statistics for "ALL" the schemas and the main problem is
due to I/O, all the disks reach 100% of their usage.

I haven't analyzed the "huge" queries causing a lot of I/O's, the main
waits events in my Statpack report are next ones:

Top 5 Timed Events
~~~~~~~~~~~~~~~~~~ % Total
Event Waits Time (s) Ela Time
-------------------------------------------- ------------ -----------
--------
db file sequential read 426,010 9,678 60.75
db file scattered read 98,033 2,469 15.49
latch free 31,605 1,800 11.30
buffer busy waits 19,365 566 3.55
direct path read 6,879 458 2.88

I have read Note:257338.1 "Direct I/O (DIO) and Concurrent I/O (CIO) on
AIX 5L", unfortunately Oracle's file systems were created like "JFS" (due
snapshot utility for Operating System) and they are mounted with big files
support, so we are going to change them according to above document to
support "cio" option.

Also, I have read another note regarding to "rwrb" option when mounting
filesystems to avoid Operating System buffer cache.

Also I have heard that minservers and maxservers need to be increased, we
have next default configuration:

oraprod@p5501:/admin/oraprod$ lsattr -El aio0
autoconfig available STATE to be configured at system restart True
fastpath   enable    State of fast path                       True
kprocprio  39        Server PRIORITY                          True
maxreqs    4096      Maximum number of REQUESTS               True
maxservers 10        MAXIMUM number of servers per cpu        True
minservers 1         MINIMUM number of servers                True

Has anybody had the same performance problems on AIX?

In this server we have "virtualization" configuration, we are going to
eliminate this to avoid "memory" and "cpu" consumption.

Any advice or comment will be really appreciated.

Kind regards,

Francisco Mtz.

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