Connection timeout between 2 VM's (proxmox 2.x)

[andrea68]

Hi, I have this strange behavior: in my proxmox I have 2 VM Linux, the first for Apache we sites and second for MySQL DB's.
From time to time apache give me error reaching databases.
If I restart the 2 VM's the situation goes normal and it seems working well.
But 3/4 days later the problem happened again.

I suspect that virtio cards does'n work well under heavy load...

How can I debug this particular problem?
Thanks in advance!

 

[ravib123]

I haven't experienced this problem before and I use virtio almost exclusively.

What does your network configuration look like? bonds? 100mb?1gb?10gb? Number of NICs? NIC model?

If you believe it is the virtio under load crashing there are alternatives to using virtio as the type of virtual NIC, you may also update to the newest version of the virtio if you haven't already.

The way to debug this issue is to disregard the virtualization layer until you have ruled out the guest software layer.

Treat it like a normal connectivity issue on two separate servers, ping, etc. Once you have definitively ruled out the guest layer then you can look at the virtualization layer, then the hardware layer.