How much RAM do you allocate your servers?

[Sonic007]

How much RAM do you allocate to your different servers?

 

I am running Windows Server 2025. Physical machine has 64GB RAM.

I currently have 10GB to the host machine, and then as virtual machines: 18GB to domain controller, and 36GB to a Sims Server running two Sims databases.

 

 

How about you? More? Less?

Edited December 18, 2024 by Sonic007

[mrbios]

Depends on the OS and service that's running. Generally as little as i can get away with without causing performance issues.

 

Hosts:

2-host HCA setup, both hosts have 256GB ram.

 

VMs start at 4GB for simple services. 8GB for servers that are a little more active. Things like papercut/print server has 12GB, SIMS has 42GB.

 

Only thing i would say is that 18GB for DC sounds like a lot? unless you have your DC doing more than just logins/DNS/DHCP?

[mavhc]

Monitor how fast it responds as you reduce the ram. Or monitor page swaps as you increase it

[Olliedawg]

Similar to above

 

Usually start at 4GB/8GB depending on what the VM will be doing.

 

If it needs more memory, then I allocate more.

 

a DC shouldn't need more than 8 unless it's doing other things.

 

Having excess memory never hurts, though.

[3s-gtech]

It really depends - one server has dynamic with a lower limit of 1GB, all the way up to 16GB for a web/DB server (that gets pretty loaded up at times). No SIMS so nothing that big needed. I just spec them based on usage and feedback.

[Koldov]

Also, regularly look in Hyper-V Manager at the memory demand throughout the day.

 

We're a small school, so I can get away with minimal allocation for each VM (and VMs have less overheads than physical machines).

 

HOST TOTAL = 32GB

 

VMs Dynamic Memory = Disabled

 

File server: Allocated = 6GB, Memory Demand = 3GB

 

SIMS server: Allocated = 12GB, Memory Demand = 8GB

 

DC server: Allocated = 4GB, Memory Demand = 1GB

Edited December 18, 2024 by Koldov

[Sonic007]

Similar to above

a DC shouldn't need more than 8 unless it's doing other things.

Having excess memory never hurts, though.

 

 

Domain Controller and File Server with a few printers.

[DavR]

4GB as a starter, then up to 8GB if that's struggling. I've not yet seen anything needing to go above that.

 

We're running a very basic setup here, though, just a couple of DCs, Print server, Legacy file server. Everything else is in the cloud.

[andy_nic]

Hosts are 256GB Ram, VMs are 8GB minimum, 16GB for SCCM,MDT,SQL & 24GB for old MIS server. Also i don't use dynamic RAM.

[Chris_Cook]

Current hosts are 128GB (x2). Most VMs on dynamic memory. Between 4 and 16 Gb depending on the application for windows servers. We don't use Sims.net anymore.

 

Modern windows is going to use spare memory for caching data, so if you have it, its probably worth it getting used.

[dmj]

Hosts have 16GB, 'servers' run in containers and use anywhere between 32MB and 1.5GB for RAM heavy apps. looking into scaling these vertically so the machine learning can work out and dynamically scale the size.

[dapaulio]

Hosts tend to cram in as much as it is compatible for.

 

Role based VMware server setup. generally 4gb upwards depending on role and importance and how much ram in the host to utilise roughly 50% - 60% of the total host memory. For failover purposes

 

Think the most one server has is either our sccm or sims server which have anywhere from 32gb to 52gb depending on the size of the school

 

Dynamic memory turned off

[Sonic007]

Do the host machines who just sit there running HyperV or whatever need much Ram or should we prioritise the Ram for the VM's?

[3s-gtech]

They need less than you may think, I tend to go with about 4GB but my hosts have usually got a bit more than that spare.

[FN-GM]

Very broad question. We have ESXi hosts with 2TB Ram each. SQL servers with 64GB but then phone systems servers with 2GB.

 

It really depends on what they are doing.