Currently server have load while there is no heavy things running, just oracle database/ application server oracle. I don't understand why server have heavy load, 22GB is under buffer, how to clean buffer/memory in AIX
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Last edited by Scrutinizer; 05-02-2012 at 07:49 AM..
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I can't see what the load is from that either, just that it's there. Try running top to see what's eating so much CPU, it could be intermittent. Or it could be lots of I/O.
I suspect buf is okay since you're not using any swap -- why shouldn't an OS use free memory as buffer, as long as it's willing to give it up when needed?
I can't see what the load is from that either, just that it's there. Try running top to see what's eating so much CPU, it could be intermittent. Or it could be lots of I/O.
I suspect buf is okay since you're not using any swap -- why shouldn't an OS use free memory as buffer, as long as it's willing to give it up when needed?
Dear Sir,
I have few questions,
1. i already paste the output of top in my thread.
2. how to check on AIX that i/o is taking load
3. how to clean buffer, is there any command that can fix buffer and memory.
Buffer is to speed up things such as I/O. I don't think you need to worry about it. AIX manages Oracle loads very well. Are you experiencing any performance hit?
1. i already paste the output of top in my thread.
You only posted statistics, not anything relevant, i.e. the list of processes below it. We can see high load, but not which.
Quote:
2. how to check on AIX that i/o is taking load
I'm not sure how to measure I/O on AIX, sorry.
Quote:
3. how to clean buffer, is there any command that can fix buffer and memory.
Please consider what I said carefully. If your system was critically low on memory, wouldn't it be using swap? But it isn't. You've used no swap at all.
I'm not intimately familiar with AIX memory management, but we get a few posters a month panicking when Linux shows "0% free". Some of them also notice that 90% is in cache instead, and reboot their systems daily to "flush" it. But cache is as good as free -- the OS won't hoard it, it gives it away at need -- so their systems were perfectly fine all along, and there was nothing to panic about.
So I think 'buf' is as good as 'free', here. 22 gigabytes of good-as-free memory that your system can use at-will, but gets borrowed for cache when otherwise idle. Why not? It's wasted when sitting around doing nothing...
You can view the I/O and the toll it takes on the machine with several tools which show different angles of the issue.
a) basics
Start with a concise description of your system: OS level, patch level, and the kernel parameters you use. AIX's memory management changed over versions and it is not clear in which direction to search for problems unless we have this information.
b) even more basics
What is your system doing and how. OK, you said "Oracle DB", but: which version, are you using RAC? ASM? GPFS? Where are the filesystems from? (SAN? NAS? NFS? disks? rotating pancakes?) What else do we need to know to investigate? I might not have asked a complete questionaire but by now you should have gotten the gist of it.
c) collect data
Find out about the status of the asynchronous I/O (depending on OS level this is switched on - with different parameters - or not).
Post the output of (always as root):
In case of the last command: issue it, then wait for 1 hour and issue it again. Post both outputs. The reason is: the "# of I/O with no fbuf" could be significant. Still, it is not the absolute value (which could come from a singular system state) that counts, but if it is relatively constant or climbing.
You might want to read the following post for more explanations about tracing errors:
I am getting a out of memory issue while executing the perl program.
Per version : /opt/acc_perl/lib/site_perl/5.14.2
Read in 54973 total records
Read in 54973 table records from table.
Out of memory!
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Hi,
In our production box i can see the Swap space using the below command
free
total used free shared buffers cached
Mem: 65963232 41041084 24922148 0 877160 35936292
-/+ buffers/cache: 4227632 61735600
Swap: 4192880 ... (6 Replies)
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I have a server with 300Gb allocated to it. Some times I observed in topas
Comp% 73 and Non comp 35% and client is also 35% and my paging is showing 92%. If my physical memory utilized only 70% then why paging is so high.
And what is relation between Comp, noncomp and client? If the memory... (1 Reply)
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top - 07:44:24 up 172 days, 18:52, 1 user, load average: 0.01, 0.02, 0.00
Tasks: 44 total, 1 running, 43 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0%us, ... (1 Reply)
Hi,
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Povide min and max memory consumption.
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Hi All
Any idea? why am I having this memory issue?
perforce@ixca-pforce-bak:/home/p4-demo-root$ diff checkpoint_offline ../p4-demo-root2/checkpoint.1150
diff: memory exhausted
Thanks a lot
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