Why is Open Media Vault (OMV) so slow when connecting to it via Open VPN (OVPN)
A couple of tests you can perform to determine which side of the network - Client (Your laptop/computer) or Server (Your OMV install).
On the Server side, you can run some simple benchmarks to determine a ballmark estimated "upper" speed OpenVPN will perform at on your RPI. I've just done the following on a RPI 3b.
openvpn --genkey --secret /tmp/secret
This creates a temporary key that you can then get openVPN to run a bunch of benchmark tests with against different ciphers.
time openvpn --test-crypto --secret /tmp/secret --verb 0 --tun-mtu 20000 --cipher aes-256-gcm
The results should be outputted in seconds. I ran the above on my RPI 3b and got the following:
real 0m17.093s user 0m17.079s sys 0m0.012s
Take either the real or user result, and use the following calculation:
3200 / <time in seconds> 3200 / 17.09 = 187.24 (Or 187.23Mbps)
You can also run it with a bunch of different ciphers:
time openvpn --test-crypto --secret /tmp/secret --verb 0 --tun-mtu 20000 --cipher aes-128-cbc time openvpn --test-crypto --secret /tmp/secret --verb 0 --tun-mtu 20000 --cipher aes-256-cbc time openvpn --test-crypto --secret /tmp/secret --verb 0 --tun-mtu 20000 --cipher aes-128-gcm time openvpn --test-crypto --secret /tmp/secret --verb 0 --tun-mtu 20000 --cipher aes-256-gcm
This just helps to narrow down if it's an encryption bottleneck (CPU limitations, or resource availability). If it's hardware limitations, then it'll be a bit more complicated to figure out.
After that, i'd review OpenVPN's settings. Compression is often a culprit. In /etc/config/openvpn (or /etc/openvpn depending how it's installed) and look for the line that says comp-lzo.
comp-lzo should be set to no. You might need to check the ovpn file settings on the client side to make sure compression isnt enabled.
Just some things to start with first. It's always a process of elimination.
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now