LinuxQuestions.org

- Linux - Virtualization and Cloud (https://www.linuxquestions.org/questions/linux-virtualization-and-cloud-90/)

- - resource (https://www.linuxquestions.org/questions/linux-virtualization-and-cloud-90/resource-4175643451/)

hi,
i like to know when i configure a virtual machine what are the things that impose how much cpu memory i must give to the vm.

the OS + application requirement dictate the resources.right?
memory -> os -4 gb ram + recommended ram (application).
vcpu ->if application require 4 vcpu then i take 5 vcpu.right?
tnx

I don't follow your reasoning. All other things being equal, if the optimal RAM for the OS is 4GB, that should take into account any applications that are expected to be run on that OS under normal usage.

As a rule of thumb, you can look at the minimum requirements for the OS (usually available on their website) and double the amount of recommended RAM. But that's only a rule of thumb.

In my experience, any mainstream Linux distro will be functional in a VM with 3GB RAM and will be very happy with 4GB RAM.

Quote:

Originally Posted by niculelu (Post 5932141)

vcpu ->if application require 4 vcpu then i take 5 vcpu.right?

I would say 4 CPUs are sufficient. The operating system' resource needs should be very low.

See it this way: Not so long ago, computers used to have a single CPU, but they were still able to run applications.

Quote:

Originally Posted by frankbell (Post 5932378)

In my experience, any mainstream Linux distro will be functional in a VM with 3GB RAM and will be very happy with 4GB RAM.

For teaching purposes, I run Centos 7, Fedora and the like in 2GB VMs, and Cirros in 512MB VMs. My home server with Samba, DNS, DHCP etc used to be a 512MB Raspberry Pi, now a 1GB Odroid. This is its current memory usage and its load average:

Code:

$ free

              total        used        free      shared  buff/cache  available

Mem:        823428      209036      129192      20320      485200      557323

Swap:            0          0          0

$ uptime

 12:40:54 up 2 days, 54 min,  1 user,  load average: 0.09, 0.04, 0.05

Lubuntu's minimum requirements used to be stated as

Quote:

Pentium II or Celeron system with 128 MB of RAM

This shows that the operating system portion of your resource requirements is practically negligible.

Kind of depends on what the host is doing. If it just serves as a host then assign all the real processors and all the ram you have available is my opinion.

What os is your host? Is your host a server? What VM are you using?

https://www.virtualbox.org/manual/

if you want to fine tune your resources you will need to monitor the system (VM) and find the bottleneck or unused resources.

Quote:

Originally Posted by linuly (Post 5934024)

i like to close it.

how does this statement relate to the original question?
what do you want to close?

if you have a problem, open a separate thread where you explain your problem.

Quote:

Originally Posted by linuly (Post 5934024)

i like to close it.

What exactly is 'it' that you want to close?

the thread is answered.

Quote:

Originally Posted by linuly (Post 5935371)

the thread is answered.

Since you didn't start the thread, you can't close it.