---
lastproofread: '2026-02-02'
---

(vyosonvmware)=

# Running on VMware ESXi

## ESXi 5.5 or later

`.ova` files are available for supporting users. You can also set up VyOS
using a generic Linux instance by attaching the bootable ISO file and
installing using the `install image` command.

:::{note}
Previous issues have been documented with GRE/IPSEC tunneling
using the E1000 adapter on VyOS guests. Use the VMXNET3 adapter instead.
:::

### Memory Contention Considerations

When the underlying ESXi host reaches approximately 92% memory utilization,
it begins the balloon process to reclaim memory from guest operating systems.
This creates artificial memory pressure through the `vmmemctl` driver. Because
VyOS does not have a swap file by default, this pressure cannot move memory
data to a paging file. Instead, it consumes memory and forces the guest into
a low memory state with no recovery option. The balloon can expand to 65% of
guest allocated memory, so a VyOS guest using more than 35% of memory can
encounter an out-of-memory situation and trigger the kernel `oom_kill`
process. The `oom_kill` process then terminates memory-hungry processes.

To prevent ballooning, configure VyOS routers in a resource group with
adequate memory reservations.

### References

<https://muralidba.blogspot.com/2018/03/how-does-linux-out-of-memory-oom-killer.html>