Memory issue

[xyz786]

We have an LPAR running aix 5.2 with ML 8 and has 32Gig memory , 12 processors running on it. It has Oracle running on it. Recently we have some performance issues with the database. Here is vmstat, svmon out puts
System Configuration: lcpu=12 mem=31488MB
kthr memory page faults cpu
----- ----------- ------------------------ ------------ -----------
r b avm fre re pi po fr sr cy in sy cs us sy id wa
2 2 2457480 722 0 10 13 1650 3409 0 2330 26233 25673 10 4 81 5
1 4 2457487 736 0 47 8 10192 95424 0 3840 10713 34696 18 6 54 22
4 2 2457487 722 0 34 25 8831 45007 0 2910 12761 29062 19 6 56 20
2 2 2457487 748 0 46 67 8743 31472 0 3199 9848 30970 14 5 58 23
1 2 2457487 664 0 22 52 8165 21558 0 3395 4495 14020 10 4 63 23
5 2 2457487 738 0 49 29 6369 14303 0 2508 10283 30752 19 4 56 20


svmon -G
size inuse free pin virtual
memory 8060928 8060198 730 465240 2454721
pg space 8454144 672579

work pers clnt lpage
pin 465240 0 0 0
in use 2243729 0 5816469 0


This server has virtual memory parameters as
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
large_page_heap_size = 0
lgpg_regions = 0
lgpg_size = 0
low_ps_handling = 1
lru_file_repage = 1
lru_poll_interval = 0
lrubucket = 131072
maxclient% = 80
maxfree = 128
maxperm = 6219520
maxperm% = 80
maxpin = 6448743
maxpin% = 80
mbuf_heap_psize = 4096
memory_affinity = 1
memory_frames = 8060928
mempools = 1
minfree = 120
minperm = 1554878
minperm% = 20
nokilluid = 0
npskill = 66048
npswarn = 264192
num_spec_dataseg = 0
numpsblks = 8454144
pagecoloring = n/a
pinnable_frames = 7595939
pta_balance_threshold = n/a
relalias_percentage = 0
soft_min_lgpgs_vmpool = 0
spec_dataseg_int = 512
strict_maxclient = 1
strict_maxperm = 0
v_pinshm = 0
vmm_fork_policy = 0
I am sure that I need to change maxperm%, minperm%, maxclient, minclient values on this one. Does anybody have any ideas what values to do we need to use in VMO for this configuration?

Thanks

 

[hfaix]

out of curiousity. what does svmon -Put 5 |pg show as the top "inuse" ram user? Is this what you expect?

 

[xyz786]

hafix,
I want to know what values do I need modify in virtual memory so I can get min CPU wait adn po value to zero.Becuase this server has 32gig so I don't think memory is an issue. This must be related to tuning parameters like maxperm%, minperm% etc...in VMO.

 

[jstacey]

My base vmm starting point. (reccomended during an IBM course)

minfree = 120 x #of CPUs
maxfree = 128 x #of CPUs
minperm = 10%
maxperm = 20%
maxclient = 20%


See if that improves performance
Jeff

 

[mbourne2006]

Don't forget, if you tune VMM you must ensure that your "maxpgahead" (or JFS2 equivalent) must satisfy:

maxpgahead =< maxfree-minfree

HTH


Kind Regards,
Matthew Bourne
"Find a job you love and never do a day's work in your life.