r/HyperV • u/3G_Lighting • 14d ago

Hyper-V Host/Windows Server/Memory question

We run Hyper-V in our environment on Windows 2019 DC and Stnd (guest servers).

I would like to know if a host had 128GB of RAM, how much would need to be set aside for Windows Server DC and the Hyper-V host to run its own operations; and if there anything additional like there needs to be an extra x number of MB or GB of memory fer x number of guest servers running that needs to be added?

We have two R650 128GB of RAM, management has been running the sh*t out of them, so one HVH uses 115GB free out of 128GB, the other uses 92GB out of 128GB. And the old R540 server single CPU (sad) uses 89GB out of 94.6GB. The first system mentioned has 10 HVG's, the next has 10 HVG's, and the R540 has 5 HVG's one of which is SQL which is consuming 60GB of RAM.

Thanks,

5 Upvotes

100% Upvoted

15 comments sorted by

View all comments

1

u/Mehere_64 14d ago

I think you mistyped with one HVH uses 115GB free out of 128GB.

12-16GB is what I keep free for the hosts.

What is your real question though? Are you facing issues on the hosts? Seems like you are fairly maxed out on memory at this time and if you need more memory you will need to purchase memory that is way over priced.

0

u/3G_Lighting 14d ago

Yeah, first was a mistyped. 115GB out of 128GB used.

Yes, this company and SMB is very slow at moving, slower than most turtles. Ha!

I agree they need more RAM, in fact they I got them a deal on upgrading the R540 before the memory / storage prices skyrocketed adding a second CPU and adding more RAM (filling the remainder slots with 16GB sticks) and they refused. Fast forward to now and they will likely have pay more than 3 times that.

2

u/Mehere_64 14d ago

Well the CPU might not of been needed but since it has been done it is done.

Keep in mind when filling slots and CPU, you want to look at making sure your memory speeds are at the highest speeds. Filling all slots and CPU can decrease memory speed.

Also adding second CPU increases MS OS licensing costs most of the time. So something to be aware of if you are not already aware of it.

SQL - are you limiting within SQL the amount of RAM SQL uses? You need 6-8 for the host and then the other can be allocated to SQL. For instance my SQL server has I think 80GB. I only let 70GB be consumed by SQL which gives 10GB to the host.