Originally posted by: SystemAdmin

Hello All,

Our 2 Lpar running with AIX 5.3 TL8 SP3. I noticed that the physical memory utilisation is always been high. Recently I have modified the tunable parameter setting as below. but no luck. Advice me if need furthur tuning require to fix this issue.
lru_file_repage = 0
maxperm = 90%
maxclient = 90%
minperm = 3%
strict_maxclient = 1 (default)
strict_maxperm = 0 (default)

Captured from nmon:

-----------|------------|-----------|------------ ¦
¦ Memory ---------------------------------------------------------------------------------------------------------------------------------¦
¦ Physical PageSpace | pages/sec In Out | FileSystemCache ¦
¦% Used 99.7% 0.4% | to Paging Space 0.0 0.0 | (numperm) 74.5% ¦
¦% Free 0.3% 99.6% | to File System 0.0 0.0 | Process 14.4% ¦
¦MB Used 7150.0MB 14.5MB | Page Scans 0.0 | System 10.8% ¦
¦MB Free 18.0MB 3569.5MB | Page Cycles 0.0 | Free 0.3% ¦
¦Total(MB) 7168.0MB 3584.0MB | Page Steals 0.0 |

---

¦
¦ | Page Faults 0.5 | Total 100.0% ¦
¦------------------------------------------------------------ | numclient 74.5% ¦
¦Min/Maxperm 1376MB( 19%) 5505MB( 77%) <--% of RAM | maxclient 76.8% ¦
¦Min/Maxfree 960 1088 Total Virtual 10.5GB | User 85.4% ¦

Captured vmstat -v outout :

root /:605 # vmstat -v
2097152 memory pages
2017009 lruable pages
4066 free pages
1 memory pools
183306 pinned pages
80.0 maxpin percentage
3.0 minperm percentage
90.0 maxperm percentage
87.8 numperm percentage
1771477 file pages
0.0 compressed percentage
0 compressed pages
87.8 numclient percentage
90.0 maxclient percentage
1771477 client pages
0 remote pageouts scheduled
0 pending disk I/Os blocked with no pbuf
0 paging space I/Os blocked with no psbuf
2228 filesystem I/Os blocked with no fsbuf
0 client filesystem I/Os blocked with no fsbuf
160538 external pager filesystem I/Os blocked with no fsbuf
0 Virtualized Partition Memory Page Faults
0.00 Time resolving virtualized partition memory page faults

Captured from vmo -a output:

root /usr/local/bin:603 # vmo -a
cpu_scale_memp = 8
data_stagger_interval = 161
defps = 1
force_relalias_lite = 0
framesets = 2
htabscale = n/a
kernel_heap_psize = 4096
kernel_psize = 4096
large_page_heap_size = 0
lgpg_regions = 0
lgpg_size = 0
low_ps_handling = 1
lru_file_repage = 0
lru_poll_interval = 10
lrubucket = 131072
maxclient% = 90
maxfree = 1088
maxperm = 1815308
maxperm% = 90
maxpin = 1692045
maxpin% = 80
mbuf_heap_psize = 65536
memory_affinity = 1
memory_frames = 2097152
memplace_data = 2
memplace_mapped_file = 2
memplace_shm_anonymous = 2
memplace_shm_named = 2
memplace_stack = 2
memplace_text = 2
memplace_unmapped_file = 2
mempools = 1
minfree = 960
minperm = 60510
minperm% = 3
nokilluid = 0
npskill = 2048
npsrpgmax = 16384
npsrpgmin = 12288
npsscrubmax = 16384
npsscrubmin = 12288
npswarn = 8192
num_spec_dataseg = 0
numpsblks = 262144
page_steal_method = 0
pagecoloring = n/a
pinnable_frames = 1913850
psm_timeout_interval = 5000
pta_balance_threshold = n/a
relalias_percentage = 0
rpgclean = 0
rpgcontrol = 2
scrub = 0
scrubclean = 0
soft_min_lgpgs_vmpool = 0
spec_dataseg_int = 512
strict_maxclient = 1
strict_maxperm = 0
v_pinshm = 0
vm_modlist_threshold = -1
vmm_fork_policy = 1
vmm_mpsize_support = 1
wlm_memlimit_nonpg = 1
#AIX-Forum

Originally posted by: unixgrl

Your memory utilization should always be high. AIX will use available memory for filesystem cache etc.
This way, you get to use the memory you purchased. As long as your system is not paging excessively or you are having some specific problem, don't worry about memory utilization. Now, if you can't "fork" or you are getting slow response time, investigate what is using the memory and make sure there isn't a runaway application.
#AIX-Forum

Originally posted by: hwyguy

Hi There,

As unixgrl pointed out, whatever is not being used by system (root) or non-system, (non-root application) processes , AIX s set out of the box to use between 20% and 80% of it's free memory as filesystem cache.

In your case, your maxclient% and maxperm% are set to 90, so AIX can use up to 90% of available memory for FS Caching.

If you look at the numclient% and numperm% numbers from the vmstat -v output, they are at 87.8 each, meaning AIX is using 87.8% of free memory for FS Caching.

Generally, you don't want to play around with these percentages unless you're running a DB server. But then you'd need to toss out FS caching altogether with either Raw LV's, CIO or DIO filesystems.

As unixgrl also pointed out, as long as you're not paging and you paging space utilization isn't growing - you're fine

Hope this helps.
#AIX-Forum

Originally posted by: SystemAdmin

Dear All,

Iam also facing the same problem do u have any tips to tune the AIX OS for Oracle Database

Regards,
Ravi
#AIX-Forum

Originally posted by: unixgrl

As posted yesterday, high memory utilization is not an issue. AIX is doing that on purpose. Be happy you are using all of the memory you purchased.

Now, if you think you have a memory issue because something is not running properly, start with a google search or a search at the IBM website. If you have a support contract with IBM, call them. If you just want some recommendations about running with Oracle, search for the documents. There are several and I have included a link to two below.

http://www.ibm.com/developerworks/aix/library/au-aixoracle/
https://www-304.ibm.com/jct09002c/partnerworld/wps/servlet/ContentHandler/VPAA-6V2C4E
#AIX-Forum

Originally posted by: hwyguy

One of the best Oracle on AIX Tuning guides I've found was written by Tomaz Vincek, located here:

http://abug.uaex.edu/ABUG_presentations/Tomaz%20Vincek%20-%20Oracle%2010g%20Performance%20Tuning%20v%20UNIX%20okolju.pdf
#AIX-Forum

Originally posted by: SystemAdmin

Hi all,

Does anybody know if there is any command in AIX 5L which shows memory usage in percentage other than svmon -F.

Also is changing these kernel parameters (maxclient% and maxperm%) enough to reduce memory usage to certain limit say below 80% or so to prevent unnecessary monitoring alerts..?

Thanks in advance
#AIX-Forum

Originally posted by: SystemAdmin

Is it also possible to see the memory usage by processes and memory usage by FS cache seperately?

Thanks
#AIX-Forum

Originally posted by: hwyguy

You might be interested in a new svmon option introduced in AIX 5.3 TL 09 and AIX 6.1 TL2.

It will show a new column known as "available memory" which includes file cache memory.

More info available here:
http://www.ibm.com/developerworks/blogs/page/aixpert?entry=new_svmon_option_for_available
#AIX-Forum