can someone explain the svmon output so I understand

[nomad1945]

Hi:

I am suspecting a memory issue with an Aix5.3 system, however I cant seem to understand how to truely see free memory, as I like to have the Database person add memory to his database but I need to know what I have free:
is the Free reported in some type of block?
I keep reading many fourums and all seem to indicate it difficult to show free memory in AIX.
An Nmon Report shows me having 15.6 of real free memory, but I am not sure if this is actual ?

thanks


svmon is

svmon -G
size inuse free pin virtual
memory 1003520 1000965 2555 234328 542205
pg space 2228224 265651

work pers clnt other
pin 198257 0 0 36071
in use 292641 0 708324

PageSize PoolSize inuse pgsp pin virtual
s 4 KB - 942149 258371 194808 476701
m 64 KB - 3676 455 2470 4094

 

[p5wizard]

AIX uses almost any memory you throw at it. If not for process images, then for file I/O buffering.

[tt]topas[/tt] may give you the info you want:

see on righthand side of topas output:
[tt]
PAGING MEMORY
Faults 85 Real,MB 4096
Steals 0 % Comp 54.2
PgspIn 0 % Noncomp 6.1
PgspOut 0 % Client 6.1
PageIn 0
PageOut 57 PAGING SPACE
Sios 57 Size,MB 20480
% Used 0.5
% Free 99.4
[/tt]

On this server (small DB2 database) 2.2GB is used as computational memory, 246MB as file I/O (tuned way down! default tuning parameters would allow filling memory with file I/O pages)

Most database software implements its own form of file I/O caching, so there's no problem in tuning this feature down.


HTH,

p5wizard

 

[nomad1945]

Thanks, I been reading on this all day, and checking my vmstats adn such, I am seeing or now understanding better how aix is using or uses memory...

This leads me to ask a question as to what would I see or expect to see, to have me think about adding more
physical memory, since it seems AIX will use anything you put in to the fullest extent.

 

[p5wizard]

Clarification:
(short explanation)
AIX will use memory for file I/O buffering if it is not used for anything else.


HTH,

p5wizard