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samjojos
Enthusiast
Enthusiast

vcsa with no VMS eating up all 16 GB ram

1 vcsa  and 1 esxi servers running in vmare workstation for lab purposes.

Without a single VM installed or running, my desktop installed RAM is chewed up at the get go.

Does the concept of dynamic memory not apply here?

When i log in with the vsphere web client monitor performance both servers show the exact usage. 1.41GB RAM.
Where does the other 15 Gigabytes go? Is it locked by the vcsa. Not very dynamic like behavior.

Also since the ESXI and the VCSA work towards the same goal of supporting the VMs, does the memory count double.
Like russian dolls. If Esxi host is running a VM needing 2GB, and VCSA manages the ESXI then do we tack on another 2GB to the VCSA as well.

Meaning do we add the VM ram needs to both servers , the vcsa and the esxi?

thanks

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5 Replies
jburen
Expert
Expert

During the installation of the VCSA you can choose a size. The smallest is Tiny with 2 CPUs and 10 GB memory. If you have chosen Small it's 4 CPU and 16 GB memory. When you have a host with 16 GB memory and a running VCSA (tiny) you would have 6 GB left for your VM's.

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samjojos
Enthusiast
Enthusiast

OK, that makes sense.

However 2 questions remain

Where does all that memory go if its not running anything?

After all the VCSA appliance is a VM like all other VMs it shoud play nice and use dynamic memory as needed no?

Having read all this theory on dynamic memory (even in Hyper-V) and how important it is,  the vcsa comes in and gobs up all of the ram.
Does one usually run a separate esxi host with only the VCSA appliance and separate esxi hosts for all the VMs?

Also if the ESXI host minimum requirements are 8 GB and we put the VCSA (needing 10 at least) on there, it would be like squeezing in elephant into a volkswagen. (isnt that the recommended approach). Plus whats left for all the VMs on the ESXi?

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depping
Leadership
Leadership

"Dynamic memory" has nothing to do with the behavior of the application running within the VM. If the app and it's services need to have a specific amount of memory based on your selected inventory size (buffers/heaps need to be sized accordingly) then the memory usage will also go up.

Having said that, which metric are you looking at? As Consumed Memory of a VM doesn't say much, it shows the pages touched, which with any modern OS typically is close to 100% of the pages.

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samjojos
Enthusiast
Enthusiast

Hello, thanks for the reply.

So the VM memory sizes are given in a table with the corresponding line of hosts and VMs it can support.
Tiny 10 Hosts 100VMs.  etc.

As written I assumed that memory resources applied to those said hosts and VMs.
Wasn't aware that the vcsa would need all those gigs of ram only to run is services.
Working with servers and heavy graphics programs I have never seen services gobble up such huge amounts of ram to basically just be alive.

Photoshop for instance needs alot of RAM. But with no layers or projects loaded it doesnt chew anything really.
I assumed the VMs and hosts would chew up those resources, and not the server itself.

I am running vcsa on esxi on vmware workstation on my desktop.
My desktop task manager shows all my ram basically gone and my PC is thrashing.

thanks

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samjojos
Enthusiast
Enthusiast

wow it seems it really does need the 10GB at least.

Here is  the breakdown

https://www.virten.net/2017/02/homelab-downsizing-vcenter-server-appliance-6-5/

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