Swap usage 0%

[Marco A.]

Hello !!

Someone knows why my glance shows the swap dev = 0% usage, and why the pseudo-swap is 90% ...?



Thank you,

Marco

[James R. Ferguson · Accepted solution]

Hi Marco:

You have memory and so process swap reservation can be satisfied with it. Turning on psuedoswap ('swapmem_on=1') is quite desirable. You have not actually begun swapping. In fact, the page-outs reported by 'vmstat' are the best indicator of actually swapping (doing I/O). Page-outs in the range 1-10 are OK but anything higher indicates performance degradation.

Regards!

...JRF...

[Marco A.]

Thank you James, mine is set 0 ..., I'll change it and see the results after doing that!! .., I believe that I need to reboot to change this value.

Regards,


Marco

[James George_1]

Yes, it needs a reboot.

James

[A. Clay Stephenson]

This is somewhat confusing:

Hello !!

Someone knows why my glance shows the swap dev = 0% usage, and why the pseudo-swap is 90% ...?

... and yet you indicate that swapmem_on=0 so what do you mean when you say pseudo-swap is 90%?

In any event, enabling pseudoswap only really makes sense on systems which have less device/filesystem swap than physical memory. On those systems which have more swap than RAM, it does nothing for you.

[Marco A.]

James..., now it is set to 1 ..., but it is showing the same..!!! .., the swap usage is 0 ..!

=( ..

Any suggestion!?!

[A. Clay Stephenson]

Swap usage of 0% is a very good thing; don't "fix" it.

[James R. Ferguson]

Hi (again) Marco:

You can always tell when you have 'swapmem_on=1' if you simply do:

# swapinfo -tam

The presence of a line beginning with "memory" indicates that pseudoswap is enabled. The absence of that line says it's disabled.

As Clay says, if swap utilization is zero, that's a good thing!

Regards!

...JRF...

[Marco A.]

Thank you James and Clay !!! ...


Regards,


Marco