Submitted 2 days ago by ml@mitexleo.one to selfhosted@lemmy.world
High Memory Usage in Proxmox
I have only one vm and I just ran "htop" in it. It's using less than 3 GB RAM. But proxmox shows 11 GB. Why?
https://www.linuxatemyram.com/
tl;dr: Proxmox shows the RAM used by the VM, which includes memory the VM considers buffer/cache.
How much of that is being used by cache? Also, certain file systems consume 1GB for every TB of storage
Proxmox thick provisions virtual machines. If you give the VM 4GB of ram the host will use at least 4GB of ram.
If you are running ZFS you also probably have an ARC cache
@ml @selfhosted in zfs? Then it's the ZFS Cache. #zfs #proxmox
@danielsalcher @selfhosted No, it's lvm.
rtxn@lemmy.world 2 days ago
Linux has two different kinds of “used” memory. One is memory allocated for/by running processes that cannot be reclaimed or reallocated to another process. This memory is unavailable. The other kind is memory used for caching (ZFS, write-back cache, etc) that can be reclaimed and allocated for other things as needed. Memory that is not allocated in any way is free. Memory that is either free or allocated to cache is available.
It looks like
htoponly shows unavailable memory as “used”, while proxmox shows the sum of unavailable and cached memory. Proxmox “uses” 11 GB, but it’s not running out of memory because most of it is “available”.