100% Swap

johnpoz

@scorpoin from what you posted I don't trust any of those.. I don't even have a swap file on my pfsense. I do not believe it creates one by default to be honest. Or it gives you an option during install..

what does swapinfo show you? What is the output of top?

top -o size

stephenw10

It does create a swap partition by default, nominally double the RAM size but......

There's no way you should ever be using the SWAP space for memory with 48GB of RAM. However the SWAP is also used for dumping crash reports. That would be a massive amount of crash data though. Have you seen any crashes?

Steve

johnpoz

@stephenw10 I doubt I would of gone with anything other than default - does ZFS not create swap, does it not show it. I see no swap with swapinfo, I see no swap in the system widget, I see no swap listed with top, etc.

Gertjan

Same thing here on a ZFS 22.05 :

no swap.

I didn't install, Netgate did that for me ;)

johnpoz

@gertjan yeah that is what I am running 22.05 zfs.. Im going to fire up my vms and check them they are running 2.6 and 2.7

edit: ok that is odd, my 2.6 vm which is running zfs does show swap.. None of it being used, but it has a 2G swap.. swapinfo shows it..

So why does my 22.05 not have one?

Gertjan

@johnpoz said in 100% Swap:

So why does my 22.05 not have one?

You installed yours from scratch ?
Mine is a SG4100 and when I opened it, it had still Texan air in it.

No, wait, it was 22.02 and I upgraded straight to 22.05.

@johnpoz said in 100% Swap:

why does my 22.05 not have one?

Because you're not needing it ? ;)

johnpoz

@gertjan said in 100% Swap:

Because you're not needing it ? ;)

hehehe - that is true.. But still curious, I doubt I would of clicked on no swap in setup. I don't recall if this was clean install of 22.05 or upgrade from 22.02...

Not something I am worried about, just more curious is all. I don't recall ever seeing swap ever be used in pfsense, as far back as I can remember even when I do recall swap being listed on the system widget, etc..

Gertjan

@johnpoz

This intrigues me :

@stephenw10 said in 100% Swap:

However the SWAP is also used for dumping crash reports.

and this is nice to know : swap is a scratch pad for crash dumps !
If the drive went bad, and the OS crashes, it will dumping the crash dump not on the head of a sick drive / root partition.

Not that I can not recall that the pfSense OS ( FreeBSD) crashed on me ...
I do see a lot of PHP errors, nearly daily these days.

stephenw10

Possibly because it's running from eMMC? The installer chooses different defaults depending on what it's installing to, the size of the install target.
Everything I've checked here has swap expect where I disabled it. Or on ARM devices where the image is written out directly.

Yes, not being able to retain crash dumps is a serious consideration when disabling SWAP:
https://docs.netgate.com/pfsense/en/latest/development/panic-information.html#install-without-swap-space

Steve

A Former User

@johnpoz said in 100% Swap:

as far back as I can remember even when I do recall swap being listed on the system widget, etc..

22.05 Swap.jpg

This is right but also if you need really much ram, it is not fully filled automatically.

scorpoin

swapinfo
Device 1K-blocks Used Avail Capacity
/dev/label/swap0 4194300 4194120 180 100%

Well it does create swap on installation it does not ask me how much space do you need during pfsense installtion.

scorpoin

well I did swapoff -a and then swapon -a

Swap become 0 :) .

Hope this will help some one else as well.

Gertjan

@stephenw10

For info : I've received my 4100 from .... not Netgate directly - from here, a reseller.
That is, from a reseller in France. It had 22.02 ( ? ) which I upgraded to 22.05 30 seconds after unwrapping it using the GUI.

It has an "128 GB NVMe M.2 SSD".
I have to try to re install from scratch, see what the "22.05" installer proposes me.
Maybe it was a 22.02 installer issue.

Or a plain human error, as these things can happen also ;)
Anyway, I real don't mind right now.

Anyway, @scorpoin :

with 25 Gb of memory .....

IMHO : when swap gets used, something must show up in the logs, with something called a 'reason'.

If no one comes up with some explanation , get ready to re install the system and ditch the config ...

stephenw10

Mmm, Unbound is using a HUGE amount of memory there.

serbus

Hello!

Try try the pcscd patch...?

John

stephenw10

That's not required in 22.05 and you should be able to see the pcscd process using the RAM if you hit that issue. But in versions before 22.01/2.6 you should certainly check that. Or upgrade!

Steve