Is there a way to tell memory usage

What’s up guys,
Is there a terminal CMD or a way to see how much “memory” qubes is is utilizing or using?

Kinda of like…
Memory installed > 128gb
Memory using > 80gb
Memory available > 48gb

Or do I have to kind of guess

Use xl top or xentop in dom0, as root or with sudo. Both commands are equivalent (xl top is an alias to xentop).
See man xentop in dom0.
You could also right click the Qubes manager tray icon ? ^^


@zithro thanks,

-so is xentop a software package I need to install in dom0?

-it never tried “right click” on qubes manager, but I will try

xentop (xl top) is part of the Xen toolstack, so it should be installed in your dom0, just try ^^

Which will tell you how much each qube is using. Then you add them all up and subtract them from the amount you have installed in the system? :slight_smile:

Yes, that was my guess ^^ Not as easy as a cmd but works.

But now I re-read the OP post (who mentions 128Gb), I’m wondering, are you asking about memory like RAM or memory like DISK usage ?

Does xentop show the allocated memory, or the actually used one?
And what is the task manager (Q → System Tools → Task Manager) showing, as it seems to under report used memory for me. Also the task manager and top also don’t seem to match.

xentop shows, among other stuff, the current memory attributed to dom0 and all domUs, and the max memory dom0 or domUs can use.
Those are the columns MEM (k) (= current usage) and MAXMEM (k).
It’s normal that MEM never reaches completely MAXMEM cause of memory handling.
I recommend using a wide terminal window for nice and easy display, otherwise it’s a mess (a bit more than 1080px is recommended).

I dunno how the Task manager counts memory, but you can compare top with free or vmstat.
Task managers, or programs like above will NEVER be able to see the memory used by domUs, it will only report dom0 usage !

To monitor real guest (domU) memory, either you open those programs from “inside” the domUs, or you use xentop !
Press d to change display update timing, default is 3 seconds. Or launch with xentop -d 1 for 1 sec updates.
Check man xentop for more.

I am asking about RAM installed on MOBO.
Just would like to know…
Qubes is See’s this much RAM installed
RAM in use
RWM left over.

That’s all my friend

Ok, so my answers above are correct.
If I’m not mistaken, by default on Qubes, dom0 will start with MEM=1024 and will go to MAXMEM=4096.
So between 1G and 4G.
The domUs usage depends on what is set in the Qubes manager, you can check in the “Advanced tab”.

If you want to see per host memory, read my posts above.
If you want to see the global usage memory, check the 3rd line of xentop, the one just above the header.
Example on my host :

Mem: 33505304k total, 33084400k used, 420904k free

Total : what you have in your host (here ~32G)
Used: what dom0+domUs are currently using (here ~31.5G)
Free: what’s available (here ~0.5G)

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That’s what I was looking for…

So in dom0 terminal, I would type…

sudo man xentop

No, man xentop is for the help file, like any help in *nixes (man COMMAND, where command is the command you want help for).
sudo xentop is for running the program.