AIX

first one is

Code:

root@xxxxxxx:/# vmstat -vs
           3170325812 total address trans. faults
             36235360 page ins
             35688435 page outs
              1739324 paging space page ins
              1895190 paging space page outs
                    0 total reclaims
           1189812439 zero filled pages faults
                18908 executable filled pages faults
            813388649 pages examined by clock
                  108 revolutions of the clock hand
             42678807 pages freed by the clock
             28247297 backtracks
                14986 free frame waits
                    0 extend XPT waits
              3448731 pending I/O waits
             69164920 start I/Os
              9369907 iodones
           6968220332 cpu context switches
            576176947 device interrupts
            201759517 software interrupts
            447769341 decrementer interrupts
               123740 mpc-sent interrupts
               123723 mpc-receive interrupts
             49116489 phantom interrupts
                    0 traps
         103693191172 syscalls
              8388608 memory pages
              8024016 lruable pages
               151961 free pages
                    1 memory pools
              1528343 pinned pages
                 80.0 maxpin percentage
                  5.0 minperm percentage
                  8.0 maxperm percentage
                  6.9 numperm percentage
               555042 file pages
                  0.0 compressed percentage
                    0 compressed pages
                  6.9 numclient percentage
                  8.0 maxclient percentage
               555042 client pages
                    0 remote pageouts scheduled
                 4698 pending disk I/Os blocked with no pbuf
                  206 paging space I/Os blocked with no psbuf
                 2228 filesystem I/Os blocked with no fsbuf
                   22 client filesystem I/Os blocked with no fsbuf
                   15 external pager filesystem I/Os blocked with no fsbuf
                    0 Virtualized Partition Memory Page Faults
                 0.00 Time resolving virtualized partition memory page faults
root@xxxxxxx:/#

---------- Post updated at 11:23 AM ---------- Previous update was at 11:19 AM ----------

Code:

OSLEVEL

5300-12-01-1016


SVMON-g

               size       inuse        free         pin     virtual
memory      8388608     8221448      167160     1527125     7698356
pg space    1572864     1318543

               work        pers        clnt       other
pin         1245797           0           0      281328
in use      7621055           0      600393

PageSize   PoolSize      inuse       pgsp        pin    virtual
s   4 KB          -    8046712    1318543    1411765    7523620
m  64 KB          -      10921          0       7210      10921


lru_file_repage,1,1,1,0,1,boolean,D,
lru_poll_interval,10,10,10,0,60000,milliseconds,D,
maxclient%,8,80,8,1,100,% memory,D,maxperm% minperm%
maxperm,641921,,641921,,,,S,
maxperm%,8,80,8,1,100,% memory,D,minperm% maxclient%
minperm,401200,,401200,,,,S,
minperm%,5,20,5,1,100,% memory,D,maxperm% maxclient%
strict_maxclient,1,1,1,0,1,boolean,D,strict_maxperm
strict_maxperm,1,0,1,0,1,boolean,D,strict_maxclient

Thanks a lot for your help

Its running Database and application.

The Server is A VIRTUAL server,how to setup these settings on the server.

the below, which value do i need to change on server. is the default values or maximum value and after changing this what will happen.

Code:

  vmo -p -o maxclient%=90

Code:

 vmo -p -o maxperm%=90

Moderator's Comments:

I asked you 2 times already to use code tags, sent you a PM and after that sent you reminder and you still do not use them

Seems you simply ignore my requests for code tags of any kind. If you continue, you will gather infraction points until your account is banned.

I assume virtual server means LPAR. There is no difference to set the parameters to a single running box.

I have checked the output you have given of vmo. I have written what needs to be changed, and you just post 2 of 4 I have posted. Those 2 allone without the other 2 make no sense.

I have written how to change them, you can copy&paste it.

90% is neither the default nor the maximum. You should check the man page for vmo to see which parameter is the current, default and so on.
Or you can use another switch like -L when calling vmo to have a detailed table.

A crude description of what will happen is:
If your percentage of RAM used as file cache is above 90%, it will only kick out these, to free up RAM for processes and their working data.
If your RAM is between the 5% and 90%, then it will usually just kick out cached files too, as long as they have not been repaged more often than computational pages, ie. the files have not been more used than some process/processing data.
If cached files fall below 5% then everything will be stolen to free up RAM to guarantee the minimum of a file cache to have the system not being slowed down by disk access for important files.

Here is an official description about it:
http://publib.boulder.ibm.com/infoce...perm_param.htm

Read carefully again what I have posted and what you ask for. Everything you need is there. If you did not understand, you can ask, but please be as precise as possible and don't post half the commands that have been recommended.

I think it is time you understand some of the basics of AIX memory-housekeeping:

How swap/paging space and memory is related

Unix is a OS from times long ago and long ago memory was VERY precious. All Unix systems can use disk space to emulate memory (RAM). Every system has:

Unix does not (really) differentiate between virtual and physical memory as far as applications are concerned. If an application asks for memory, it gets some, but the application has no control (in fact no knowledge) about where this memory comes from. It can come from the paging area or the real memory. (There are ways to circumvent this, but more later.)

The kernel itself manages where the memory is in fact taken from: first it gives out all the memory it has, because memory is very fast compared to disks. Only when real memory is exhausted it shovels the least-used memory pages to the swap ("swapping out") and makes room for more memory demands. At some point, even the least-used memory page is used again and then, the kernel looks for the least-used memory page(s) again, puts them in the swap, making room this way ("swapping out" again) and shovels the used pages back in ("swapping in"). The application will not notice all this, but the user will, because this swapping out/swapping in takes noticeable time. The more often it happens the slower the system will appear.

There is the command "vmstat" to see this happening. The columns "pi" (page in) and "po" (page out) are the number of memory pages swapped in and out in the sampling interval. Issue

Code:

vmstat -tw 1

to set the sampling interval to 1 second. (I don't know about you but my inner clock is counting in seconds, so this is a good starting point for me. Use longer intervals like 300 [=5 min] for long-term monitoring.) A "memory page" in AIX is usually 4k, so multiply with 4096 to get the sizes in bytes.

Do you need a bigger swap space?
Yes and no. No, because memory is already very cheap and you might want not to have to swap at all anyway. You might need to increase the RAM, use AME (a sort of RAM compression done transparently), use shared RAM (AMS) or whatever to make the paging space unnecessary. If you have a small unused paging space or a large unused paging space does not matter at all.

Yes, because paging space is your "plan B" if memory is exhausted. You have 32GB physical memory installed, so if you exhaust that at some time in the future you will do so probably by more than the mere 6GB you now have in contingency. Be aware, though, that this is pure conjecture. It might be that under very certain circumstances the 6GB might be optimal. Increasing the paging space adds nothing to the systems resources, it just pushes the point at which the system becomes absolutely unusable a bit farther back. To compare with a car: this is not a better working brake or a bigger motor, it is a bigger safety belt.

Notice the difference between swapping and swap usage
Notice that swap usage does not hurt, only the activity of swapping in or out memory pages does. What does that mean? Some process would be ready to run, but its memory pages are in the swap. In this case the process is stopped, its pages are swapped in by the kernel (and probably some other pages are swapped out instead) and only then it can start to run. In the meantime other processes could use the system (its processors, or whatever), but if all processes otherwise ready to run would be affected by swapping activity he machine effectively does nothing but wait. This is what makes it appear to be slow.

Now suppose there is a huge (in terms of memory) process, which only runs once a day: it might lurk in the swap, will be swapped in once a day then run for some time and be swapped out again. It would allocate a big amount of swap, but the actual swapping activity taking place would be minimal. This would not hurt at all in terms of perceptible performance.

With databases involved everything is different, of course
I said above that applications have no say where the memory they request comes from. This is in principle true, but there are exceptions to this rule. It is possible to explicitly ask for memory coming from RAM and should never be swapped out (so-called "pinned memory"), though this should not be done lightly (if everybody asks for physical memory it will be exhausted soon AND the swapping feature of Unix would effectively be disabled). Database software, though, often use memory to cache often-used contents of the database and it would make no sense whatsoever to have that swapped out. Therefore database software allocates "pinned memory" for some vital parts. In Oracle this is called "SGA" (System Global Area) and its size can be customized.

Talk with your DBA about how big it is and how big it needs to be (they always go for "as big as possible and bigger is better" ;-)). As Oracle does its own cache on dedicated Oracle servers you might want to cut back on so-called "file memory" (all the physical memory not immediately used is dedicated to file caching by the AIX kernel) and give the room made free this way to the database software.

I hope this helps.

bakunin

Zaxxon - is well ahead of me in terms of what needs to be said.

Before 1999 there were recommendations for having paging space at @X installed memory, and before 1996 (AIX v3) there were cases where 3X was recommended (i.e., when installed memory was <128 MByte - Mega, not Giga Byte).

Starting with AIX 4.3.3 - ML3 I believe, AIX introduced a new algorthim - differed paging space. From that time, the amount of paging space needed is drastically less.

On my main (personal) system, with 9G of memory I have 512M Byte of memory.

Code:

michael@x054:[/data/prj/linux/debian]lsps -s
Total Paging Space   Percent Used
      512MB               3%

There will always be some paging space used - this occurs "during boot" as far as I can tell.

The difference between before AIX 4.3.3 ML3 and now is that paging space is only allocated when it is actually needed - NOW - while BEFORE, it was allocated (but not written!) when memory got malloc()ed (PSALLOC=early), or when the page was initially touched in physical memory (PSALLOC=late).

So, seeing paging space is 81% consumed - yes, increase it - make it a an additional space that is not automatically restarted. This is to prevent a "panic" like crash - avoid happenings like this whenever you can.

HOWEVER - the real problem is not your "lack of paging space" (although 9G (~= 25% of physical memory) does have a nice feel to it.) - your problem is that applications are needing it - as bakkin talks about.

You need to spend time figuring out WHY applications are needing the support of paging space. This is NOW - not 1988-1997 time frame when paging space was common - and actually needed because of the economics of purchasing memory.

In short, you need additional paging space because it will prevent a "panic crash" - but your problem is that your system needs paging space to prevent a crash. Find out why your system does not fit in 32G of memory. If there are valid reasons - increase the memory rather than the paging space.

My two cents - and hope it helps!

Michael