Ways to Improve IO Speed

• Put redo on dedicated disk 
• Use Raw Device or Direct IO  
• Consider Ram Disks 
• Alternate disks for redo and archiving of redo  

Procedure to reset an account on Aix

When this message is received you'll have to reset the account:

3004-303 There have been too many unsuccessful login attempts; please see
the system administrator.

Procedure to reset the account:

chsec -f /etc/security/lastlog -a "unsuccessful_login_count=0" -s <username>

chuser "account_locked=false" <username>

Chsec is the command needed to change an user's security attributes.

How to determine the physical RAM size on Aix

lsattr -E -l sys0 -a realmem

vmstat relevant columns with descriptions

Column	Description
kthr	Kernel thread state changes per second over the sampling interval.
r	Number of kernel threads placed in run queue.
b	Number of kernel threads placed in the Virtual Memory Manager (VMM) wait queue (awaiting resource, awaiting input/output).
p	The number of threads waiting on raw I/Os (bypassing journaled file system (JFS)) to complete.
fi/fo	Number of file pages paged in/out per second.
cpu	Breakdown of percentage usage of CPU time. For multiprocessor systems, CPU values are global averages among all processors. Also, the I/O wait state is defined system-wide and not per processor.
us	Average percentage of CPU time executing in the user mode.
sy	Average percentage of CPU time executing in the system mode.
id	Average percentage of time that CPUs were idle and the system did not have an outstanding disk I/O request.
wa	CPU idle time during which the system had outstanding disk/NFS I/O request(s). If there is at least one outstanding I/O to a disk when wait is running, the time is classified as waiting for I/O. Unless asynchronous I/O is being used by the process, an I/O request to disk causes the calling process to block (or sleep) until the request has been completed. Once an I/O request for a process completes, it is placed on the run queue. If the I/Os were completing faster, more CPU time could be used.
pc	Number of physical processors consumed. Displayed only if the partition is running with shared processor.
ec	The percentage of entitled capacity consumed. Displayed only if the partition is running with the shared processor.

Aix Virtual Memory Management internals

Aix CPU/Kernel monitoring and tuning tools

Tool	Function
topas	Reports selected local and remote system statistics
vmstat	Reports virtual memory statistics
sar	Collects, reports, or saves system activity information
wlmstat	Shows Workload Manager (WLM) per class resource utilization statistics
wlmmon	The wlmmon and wlmperf commands provide graphical views of Workload Manager (WLM) resource activities by class
xmperf
tprof	Reports processor usage
pprof	Reports CPU usage of all kernel threads over a period of time
nmon	Displays local system statistics in interactive mode and records system statistics in recording mode
schedo	Manages processor scheduler tunable parameters

Aix Disk I/O monitoring and tuning tools

Tool	Function
filemon	Monitors the performance of the file system, and reports the I/O activity on behalf of logical files, virtual memory segments, logical volumes, and physical volumes
fileplace	Displays the placement of file blocks within logical or physical volumes
lvmstat	Reports input/output statistics for logical partitions, logical volumes and volume groups. Also reports pbuf and blocked I/O statistics and allows pbuf allocation changes to volume groups
iostat	Reports Central Processing Unit (CPU) statistics, asynchronous input/output (AIO) and input/output statistics for the entire system, adapters, TTY devices, disks CD-ROMs, tapes and file systems
wlmstat	Shows Workload Manager (WLM) per class resource utilization statistics
wlmmon	The wlmmon and wlmperf commands provide graphical views of Workload Manager (WLM) resource activities by class
ioo	Manages Input/Output tunable parameters