How is this possible?

[ozgurerdogan]

I decided to upgrade ram from 4 GB to 8 GB as it was using %80 of ram. But after doubling it, it still uses %80 of ram. See screen shot please.

 

[mikesrus]

ram of what VM or PVE host?

 

[ozgurerdogan]

it is kvm's

 

[sg90]

Is the graph the ram display for the whole node or a particular VM?

If a VM which OS is running within the VM?
Do you have quest-agent installed?

 

[ozgurerdogan]

it is particular VM windows 2019 and agent is installed. cpu is kvm64

 

[ozgurerdogan]

btw this is a zfs node.

 

[mikesrus]

what show task manager inside VM, and may be some database software iside VM?

 

[ozgurerdogan]

could it be baloon driver related?

 

[sg90]

could it be baloon driver related?

Well how much ram does windows show using in the task manager?

 

[ozgurerdogan]

it is same as PVE shows. I am sure if I give more ram, vm will use it very interesting.

 

[sg90]

it is same as PVE shows. I am sure if I give more ram, vm will use it very interesting.

Then it is down to what your running within the Windows VM.

I am guessing your running something like SQL or some other software that will make use of any available ram as cache, if your assigning it ram it will use it to increase performance in general.

 

[ozgurerdogan]

You might be right. What do you suggest. It is sql maybe using it.

 

[sg90]

Nothing you need to do, SQL will always use the ram available to it.

If you can spare the extra RAM for the VM leave it as it is, if you can't then take some back.

The more RAM it has the more it can cache and perform better than always reading from disk.

 

[ozgurerdogan]

Ok I set a limit in sql and ram usage dropped. But it is slowly increasing. I have seen this slow increase before. What could be doing this? I am using zfs.
See ss please.

 

[sg90]

Your OS and SQL will still cache into RAM.

I’m not sure what your worrying about, ram is there to be used, no point forcing it not to cache in ram and lose performance.

If anything else needs ram the OS will take back the cache use and hand it over to another application that requires it.

Your best just leaving it along and letting SQL deal with its own ram use.

ZFS only has an effect on ram use on the node level not VM level.

 

[ozgurerdogan]

My worry is how much ever ram I give it, it will use to. It feels like vm is heavy loaded but in fact it must not be.

 

[sg90]

Correct because it will use ram to cache, you don’t need to worry. Give it as much ram as you can afford to.

It will use that to cache and remove the load on the disks directly. RAM is there to be used.

 

[jim.bond.9862]

In most modern OS RAM usage is not indicative of system being overloaded.
It used to be the case. But not anymore.
Nowadays an OS will use whatever ram is available to increase performance and will free up memory as needed for other apps and proceses on demand.