Swap Space

[Whitehorse_1]

Hi Folks,

I got a doubt., Did the Device Swap has got more significant in CPU Utilizations.,???

[Alessandro Pilati]

Whitehorse,
I haven't exactly understood your question...
do you mean if an excessive swapping activity creates also a CPU overcharge, caused by the intensive I/O activity on the swap device?

[RAC_1]

Not much. The real problem is when swapping starts. File system swap is most utilization centric with respect to disk, cpuu, memeory.

[morganelan]

I think Device Swap is not much significant in CPU utilizations, this device relate with physical memory.We normally to have swap 2X our RAM, unless specified by our application.To see your swap info use:
#swapinfo -mat

[Raj D.]

Hi Whitehorse ,

Device Swap has got more significant in CPU Utilizations.,??? No.

When you add and use a device swap , you can check with glance no much cpu uses and its ignorable.
Rather you can check with # swapinfo -tm , how swap is being utilised.

Check also :
# vmstat 5 5 [ check pi/po values , if its non-zero value , excessive swaping is happening , if its zero its ok. ]

hope this will helps..

Cheers,
Raj.

[Whitehorse_1]

Hi all,

OK..fine.. Assume if i got 100% CPU utlization will a filesystem swap(taking space from the disk) and adding helps oozing out some CPU load...

Thxs a million ..!!

[Vibhor Kumar Agarwal]

I don't think so.

This condition happens when the process CPU picks to run, doesn't have its data in memory.
So it goes for the SWAP.
Now if you add more disk/swap area, there will be no effect.