Observation: SAP uses swap space even when OS has available unused memory

Hi Folks,
It is my understanding that any memory not used by the Linux OS itself or the SAP application is available for Linux to use for I/O buffers and file caching. When the SAP application requires more memory I would expect Linux to take memory away from itself (release I/O buffer and/or file caching memory).
We have observed that SAP uses swap space even when there is memory available. Is there some feature in SAP kernel or some ABAP construct that causes SAP to prefer swap space over available memory? Or maybe there is a Linux kernel setting that influences SAP's use of swapping.
Regards,
Zaz

Hi Mike
You did not mention which distribution you have. Under SLES there is is a parameter called SWAPPINESS, which controls the buffering/swapping.
cat /proc/sys/vm/swappiness
If you don't already know, you can see the memory usage with the free command.
root # free -m
             total       used       free     shared    buffers     cached
Mem:          7987       7901         85          0        364       4262
-/+ buffers/cache:       3274       4712
Swap:        15999          0      15999
As far as i know, in this example 3274 is memory used by SAP and other processes and 4712 is cache. Please correct me if i am wrong.
Regards
Michael
Edit: a low swappines, for example 10 means to reduce cache first, a high swappiness (example 100) means page out processes first
Edited by: mho on Jun 20, 2008 11:21 AM

Similar Messages

Database Instance Using Swap Space even When There is Plenty of Free RAM

Hi,
I am facinga strange issue in oracle on solaris 5.10
Platform:solaris 5.10
Database version:11.2.0.1.0
Our database Instance Using Swap Space even When There is Plenty of Free RAM.
We have 80GB of physical RAM, 32GB is set to oracle SGA_MAX_SIZE
memory parameters:
memory_max_target big integer 32G
memory_target big integer 32G
sga_max_size big integer 32G
sga_target big integer 32G
but still oracle is taking memory from swap even though we have enough physical memory.
please find the top output
load averages: 0.09, 0.18, 0.84 01:07:49
134 processes: 133 sleeping, 1 on cpu
CPU states: 99.4% idle, 0.4% user, 0.3% kernel, 0.0% iowait, 0.0% swap
Memory: 80G real, 69G free, 35G swap in use, 49G swap free
PID USERNAME LWP PRI NICE SIZE RES STATE TIME CPU COMMAND
1052 oracle 13 59 0 95M 66M sleep 13:16 0.07% oraagent.bin
10256 oracle 1 59 0 32G 835M sleep 0:00 0.03% oracle
1227 oracle 15 59 0 78M 56M sleep 4:27 0.02% ocssd.bin
9524 vector1 112 59 0 1704M 776M sleep 45:04 0.02% java
988 oracle 38 59 0 119M 92M sleep 3:00 0.02% ohasd.bin
1297 oracle 1 101 -20 453M 390M sleep 2:47 0.02% oracle
1765 oracle 1 101 -20 32G 329M sleep 2:45 0.02% oracle
10258 oracle 1 59 0 32G 345M sleep 0:00 0.02% oracle
10259 oracle 1 59 0 3400K 2024K cpu/20 0:00 0.01% top
1777 oracle 1 59 0 32G 342M sleep 1:14 0.01% oracle
1246 oracle 6 59 0 56M 44M sleep 1:22 0.01% diskmon.bin
1803 oracle 1 59 0 32G 514M sleep 0:30 0.01% oracle
1215 oracle 15 59 0 71M 46M sleep 1:12 0.00% cssdagent
1307 oracle 1 59 0 453M 390M sleep 0:45 0.00% oracle
1217 oracle 11 59 0 81M 49M sleep 0:35 0.00% orarootagent.bi
Vmstat output:
$vmstat 5 5
kthr memory page disk faults cpu
r b w swap free re mf pi po fr de sr s3 s3 s3 s3 in sy cs us sy id
0 0 0 53698448 73900568 20 81 32 6 5 0 1 -0 0 1 -0 2235 1447 1984 1 0 99
0 0 0 51196160 72037552 1 13 0 0 0 0 0 0 0 0 0 2505 1403 2204 0 0 100
0 0 0 51193488 72035864 55 380 0 0 0 0 0 0 0 0 0 2487 2143 2203 0 1 99
0 0 0 51183856 72030176 0 0 0 3 3 0 0 0 0 0 0 2496 1370 2182 0 0 99
0 0 0 51182648 72029112 22 117 0 0 0 0 0 0 0 0 0 2503 1408 2193 1 0 99
$cat /etc/release
Solaris 10 10/09 s10s_u8wos_08a SPARC
Copyright 2009 Sun Microsystems, Inc. All Rights Reserved.
Use is subject to license terms.
Assembled 16 September 2009
I refered the metalink document id: [ID 761960.1]
Database Instance Using Swap Space When There is Plenty of Free RAM metalink note [ID 761960.1]
and tried the disabling the sga_max_size and memory_max_target and memory target with all different combination but no use.
We have one more box where same setup was configured in solaris platform but there the above memory parameters are not disabled but it is not using swap space it takes memry only from physical RAM
Can any one throw some lights on this issue. It wopuld be great if I come to know where the exact problem
Thanks in advance
With Regards,
Boobathi P

Hi,
I didn't say I am not using 11gr2 memory parameters I am using all the automatic memory parameters but the thinks is as per the metalink note I tried by disabling the automatic memory parameters. but that didn't help me in preventing unnecessary swap usage. So I reverted. now it is using automatic memory parameters.
so What is the solution for this?
With Regards,
Boo

I want to use only edge even when 3G is available ...

I want 2 stay online most of the time with IM apps but 3G all day is killing the battery can I only allow the edge 2 connect on 5800?
Solved!
Go to Solution.

mariodouh wrote:
I want 2 stay online most of the time with IM apps but 3G all day is killing the battery can I only allow the edge 2 connect on 5800?
If you go to Menu > Settings > Connectivity > Network > Network mode - you can change from default "Dual mode" to "GSM" if you want.
Happy to have helped forum with a Support Ratio = 42.5

IPhone 4S uses 3G data even with WiFi network available

I've been trying to figure out why the iPhone still uses 3G data even when it has a WiFi network available. It's usually just a few MBs per day, and as such - I attributed to niotifications, location services, etc.
But today, I got a really nasty surprise...
As I woke up, my iPhone showed the WiFi indicator as usual, but internet was slow... as if it was using cellular data. Something i quickly confirmed by trying to access stuff on my internal LAN and not being able to.
Worst of all, my iPhone went through over 600MB of cellular data overnight - that's my entire data limit for a month! - meaning I'll have to pay for neary 400MB of excess data usage paid at overly inflated prices (I'll be paying nearly 3x my monthly bill just for the excess data!!!)
As if all the bugs I've been facing weren't enough: Invalid SIM, showing full strength 3G signal when it's actually "offline"... Now I have to face stupidly wasted mobile data when I'm at home within WiFi range?
I've been an iPhone use for years, and have upgraded every year to the new models... but this iPhone 4S has been my worst experience ever with a mobile device, and ruined all the trust I had in Apple devices...
I sincerely don't know what to do next... if I'll still wait for a 5.1 update that may/may not fix all the issues I (and thousands others, as seen by the discussions here) have been having... or if I cut my losses and try my luck elsewhere...
Tired of serving as a guinea pig and doing all this debug work for Apple...

The WiFi data is recorded separately - and the mobile data use was verified using the operator "reporting" service (and later sending me the warning SMS of the data use).
The iPhone was in the home screen, locked, and "sleeping" when the data was used, so the only option would be the iCloud backup - which, in any case, should never ever use the 3G data (and never has until today).
If the WiFi was not working, then it should either: not have internet access; not show the WiFi connected signal in the status bar. As it was, it was showing WiFi access, but using the mobile data just the same.
Which, from what I understand, could have "tricked" iCloud into doing its regular backup thinking it was over WiFi... but in reality doing it over cellular data.

Can I force my phone to make calls using WiFi, even when wireless is available?

When I was in the UK a couple years ago I could make calls back to USA using WiFi, because the wireless service was incompatible with my phone.
When I was in the Dominican Republic last year, even though I used GrooveIP and Google Voice, I came home to a $400+ wireless roaming bill, I think because the wireless service there IS compatible. So how do I force my phone to make calls using WiFi, even when wireless is available?

Hey there FredW,
A $400 bill would certainly cause my jaw to drop so I absolutely want to provide you steps to prevent this from happening going forward.
To avoid data charges you are going to want to make sure that Data roaming is turned off,http://vz.to/18oRFuS.
You'll also want to disable mobile data,http://vz.to/1hCPg4Q.
When using services such as GrooveIP, Google Voice, Skype you are going to want to make sure that you are connected to WiFi. Here is how to set up a WiFi connection,http://vz.to/II1jP6.
Let us know if you have any additional questions.
NicholasB_VZW
Follow us on Twitter @VZWSupport

Allocated heap memory goes up even when there is enough free memory

Hi,
Our Java application's memory usage keep growing. Further analysis of the heap memory using JProbe shows that the allocated heap memory goes up even when there is enough free memory available in the heap.
When the process started, allocated heap memory was around 50MB and the memory used was around 8MB. After few hours, the inuse memory remains at 8MB (slight increase in KBs), but the allocated memory went upto 70MB.
We are using JVM 1.5_10. What could be the reason for heap allocation going up even when there is enough free memory available in heap?
-Rajesh.

Hi Eric,
Please check if there is any error or warning in the Event Viewer based on the data time?
If there is any error, please post the event ID to help us to troubleshoot.
Best Regards,
Anna

Using Swap space

Hi All
I have an application consisting of lots of processes. When ever I start my applicaiton, I seem to be running out of swap space. I see that there is a lot of reserved space. Means the applications are attaching shm and/or requesting mallocs. Is there any way to fix this, either by debug by some mem tool or by any compiler options? I am running this on Solaris 10 with binaries compiled in sun studio 11 compiler set.
Thanks in advance.

Hi All
I have an application consisting of lots of
processes. When ever I start my applicaiton, I seem
to be running out of swap space.How are you viewing this?
I see that there is
a lot of reserved space. Means the applications are
attaching shm and/or requesting mallocs.Also, just the forking will need to reserve space as well.
Is there any
way to fix this,I don't see that anything is broken. What are you trying to fix? You need memory to run lots of programs. Have you tried increasing the swapfiles on the machine? That will handle increased reservation requirements.
Darren

TC 3TB shows 434MB of used drive space even after full erase

Hello! Purchased a pre-owned TC 3TB MD033.
Device shows 2.7TB drive capacity and 2,7TB available. (And that is normal as the TC shows binary size, not decimal).
BUT! In the same time it reports that 434GB are USED! See the picture.
Is it normal for a pre-owend TC?
(I've heard it's normal because TC backup files are encrypted and behave not like ordinary files.)

Just use erase in the airport utility.. even if it was erased before do it again.. It can use some space .. 180MB. If I remember but certainly not 434GB.. the previous owner has left a backup or files on it..
If you do an erase and still have 434GB used something is wrong.. report back..
Your picture is not showing.

I can not move my apps around like I use to. Even when connected to ITunes.

Since using the new IOS 7.02 and ITunes I can not move one app from one home page to another. Even when hooked up to the PC.

Try logging out of your account on the iPad by tapping on your id in Settings > Store and then log back in and see if it then works.
If that doesn't solve it then I've also seen suggested going into Settings > General > Date & Time and change the date to a few months in the future and then re-trying

How to find Oracle is using swap space or not?

Hi,
I have a SuSe Linux database server on which 2 Oracle 10g databases and one MySQL server is running.
I can see a very little swap space is being used in the server while there is almost 100% RAM utlization.
I want to know if my Oracle databases are using swap or not. If it is using, how much of swap being used currently by each Oracle database?
Can someone please guide me on how to do that?
Thanks in advance for your help.
Regards,
Murali Mohan

I did "vmstat 1 10" and here is the output.
What I want to know how much swap space is used by each of my oracle database while the below output is for total swap usage
procs -----------memory---------- ---swap-- -----io---- system ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
0 0 2366860 36996 81660 9458664 67 44 4160 356 9 13 5 3 82 9
0 0 2366860 38224 81748 9458576 0 0 0 512 1041 369 0 0 99 1
1 0 2366860 38224 81748 9458576 0 0 4 80 1053 293 6 0 93 0
2 0 2366860 38224 81752 9458572 0 0 80 40 1467 956 22 7 70 1
2 1 2366860 38248 81760 9458564 0 0 0 580 1150 444 32 17 50 1
1 1 2366860 38124 81808 9458516 0 0 360 1040 1672 1158 28 13 51 8
2 0 2366860 38124 81832 9458492 0 0 84 288 1380 931 33 10 57 1
2 0 2366860 36596 81884 9458388 52 0 52 4088 1098 475 36 16 46 1
2 0 2366860 38188 81916 9458356 0 0 144 1096 1251 570 36 12 49 2
2 0 2366860 38180 81916 9458356 0 0 68 136 1595 1134 28 9 63 1

Is useing swap space and hibernation secure?

As I understand it when you hibernate your system the ram is written to the swap space and the computer powers down. Is this secure and encrypted?

seniorsassycat wrote:As I understand it when you hibernate your system the ram is written to the swap space and the computer powers down. Is this secure and encrypted?
No, it is not. But are ypou running arch from an encrypted filesystem? Otherwise it would be pojntless. Anyway the normal swap is not encrypted either, at least by default.
Last edited by olive (2012-06-18 13:53:22)

LR uses 10% cpu even when idle

I noticed that LR 3.3 consumes 10% cpu all the time even when it sits in the background (and I'm working within an other application and I have NOT started any batch)?!
After putting LR in the foreground (as active application) it consumes less then 5%?!
What is it doing??
Are there some settings to reduce/switch of background tasks?
(I already switched off memorycard detection for import, and XMP autosave)

hherbos wrote:
Thank's - it was the RC_ChangeManager Plugin! - I removed it and there's now no notaceable CPU consumption of LR when sitting in the background.
It's really annoying that LR misses a lot of really tiny things that Adobe developers could implement them alltogether in only a some days. But no - you have to install lots of plugins, which lack of the poor LR api.
Well, the SDK is actually pretty complete, and quite powerful. Lr is a heavily threaded application, and this is exposed to some extent by the SDK. For plugin authors, this is really nice. It offers a way to make very powerful additions to Lr that don't belong in the core product, but behave as if they are.
But it means that a poorly written plugin can soak up a fair amount of resources. Note, however, that a plugin cannot totally steal all resources. There is a governor on that, so the worst you will see is this sort of problem -- annoying, maybe, but not disasterous.
And remember that the vast majority of plugins will use the tasks and threads handed to it from the application, and will never exhibit these symptoms. It is only some sorts of plugins written in a specific manner that would ever impact overall application execution profile. So, you could install many plugins and never see a change in behaviour whether 1 or 10 were enabled. But install and run one that cycles hard on blocking activity and you will see this problem.
There is always a trade-off. Plugins make the application very flexible, but with this flexibility comes some risk. There is no perfect solution and there never will be. (Adobe could never implement all plugin behaviour everyone would want as first-class features in the core product -- this is impossible.)

Z3 Compact using mobile data even when disabled.

Hey there,
my new z3 compact is connecting to the mobile internet every 3 hours and causing costs! Mobile data is disabled in the setting and in the quick menu. WIFI is available all the time. In the settings it shows 0MB of volume for all apps. Besides the preinstalled apps and widgets I use only some apps wich are well known and can be trusted.
Now how can I see wich app/widget is connecting? And who pays my bills?? It seems I cannot trust my device and I dont like that idea.
Any advice? The Support didnt help much - told me to reset and wait for the next bill to see if it worked...
Gabriel

If you can't access some live statistics from your mobile operator at least you can try this.
Go into Settings / Power / Battery Usage.
There will be a graph showing battery discharge ratio and list of all apps using power below.
When you click on the app (yes, I know it will be annoying) for some of them there will be "Mobile data sent" and "Mobile data received".
For example in my phone under "Android OS" I have -
CPU total 1 hour 1 minute
CPU main - 16 seconds
Keep active - 9m 59s
Data received - 6,34kB
Data sent - 14,14 kB
Wifi received - 484 bytes
Wifi sent - 531 bytes.
Check every single app on the list. Maybe you will find it there. I suspect Google Play Services. Someone on the forum mentioned that they ignore disabling auto update. Maybe Google messed something with disabling mobile transmission?
There is a one, very hard way to disable accessing mobile network data if you don't need that.
Head over to Settings / More / Cellular Networks / Access points name (APNs).
There will be APN for your data transfers and for MMS. Leave MMS alone but delete data APN. You will be able to configure it again manually but as long as there will be no APN for data transmission your phone will not be able to connect to your operator and cause costs.
Best regards,
Sergio PL
Xperia Z1 / Nexus 7 (2012)

Firefox uses full internet even when no tab is active

Hello,
From the past few days I have seen a unusual activity in firefox 5. I have bit defender antivirus which has firewall included in it which shows the activity of each application and helps to create firewall rules for each and every application. Firefox behaves normal and uses the net speed for the webpages until I check any online videos. The firewall shows me that firefox is accessing my full net speed even after I close the online video streaming. When I block the firefox in firewall no net usage is seen. Then I have to restart firefox so that I can use it with out effecting the other tabs or else the other tabs never load after I watch the online video and even after closing that particular tab.
Please tell me what should I do?

All plugins disabled in safe mode, still no luck...

Safari Web Content - Constantly using CPU time even when no tabs

Hello,
I have a MacBook Pro Retina (2012), with 16GB of RAM. It is running OSX Mavericks (10.9.4). Recently, I have switched from using it with multiple external monitors, to using it on its own. Here, I have noticed unusually raised usage temperatures - even without any applications (other than Safari) running. Looking at Activity Monitor, it seems Safari Web Content (com.apple.WebKit.WebContent) is constantly using one of my CPUs. Whilst it does not affect the speed of the computer much, it does mean that "idle" temperatures are significantly raised, which is a pain when I am using it on the road.
I have done the following, all of which have not succeeded:
Disabled all Safari extensions
Cleared the cache
Closed all tabs
Sampled the process - unsure of what the output of this means, but if you require it, then I can post it here.
I am unsure what else to try. Currently, the only action that resolves the issue is completely quitting Safari - obviously, this isn't something I can really do for normal usage.
Has anybody come across this before? Is there anything more I can do to investigate the issue? Finally, is there a known fix for this problem?
Thank you in advance,
Richard

Do you have any of the following installed:
anti-virus/internet security software?
"Cleaning" or "tuning" software?
third-party backup software (not Apple's Time Machine) that came bundled with an external hard drive?
online backup software (Carbonite, OneDrive, GoogleDrive)?
Also please do "About Safari" from your Safari menu so we can verify your version. On July 11, Apple inadvertently posted a Seed release of a Safari version still under development for the next OSX version. People who had updates set to "automatic" got the "not ready for prime time" version. If you have Safari 7.1, you were "gifted" with that little bag of post-processed cattle feed.

Observation: SAP uses swap space even when OS has available unused memory

Similar Messages

Maybe you are looking for