Performance Issues with VMs and Host During Compilation on Proxmox – Possible SSD Bottleneck?

[oblinez]

Hello Proxmox community,

I’m experiencing performance issues on my Proxmox VE setup and would appreciate some guidance. I’m running a Proxmox host with dual processors (88 threads total, with less than half allocated to VMs), plenty of spare RAM, and all VMs stored on a single Kingston SSDNow UV400 480 GB SSD. The issue occurs when I compile programs in one of the VMs: the other VMs and even the host become slow and unresponsive, with noticeable lag and occasional freezes.

Here are the details of my setup and observations:

• Hardware: Dual-processor zeon server with 88 threads, ample RAM (not fully allocated), and a Kingston UV400 480 GB (SATA) as the storage for all VMs.
• Proxmox Version: Virtual Environment 8.2.7.
• Issue: When compiling software (e.g., large programs or with many dependencies) in one VM, the other VMs and the host experience significant slowdowns or freezes. CPU and RAM usage are well within limits (I have plenty of spare capacity), so I suspect a disk-related bottleneck.
• Background: I previously ran these same VMs on Hyper-V, where I didn’t experience any issues with slowdowns or freezes, even under similar high workloads like compiling programs. This makes me suspect there might be a configuration or performance difference in how Proxmox handles disk I/O compared to Hyper-V.

I’m wondering if this could be related to the SSD’s performance, such as its IOPS or throughput being insufficient for multiple VMs under heavy I/O load (e.g., compilation generating many small, random I/O operations). Could this be a Proxmox-specific issue, such as I/O scheduler configuration, SATA controller contention, or another factor I’m overlooking?

Any insights or suggestions would be greatly appreciated.

Thanks in advance