I posted a similar discussion in MAAS discourse at Setting Mellanox RX and TX ring sizes with MAAS - Features - MAAS | Discourse
I’m using MAAS and Juju to deploy OpenStack on top of servers that have Mellanox MT27710 ConnectX-4 Lx NICs. After some performance tests, I found that raising the RX and TX ring sizes of the Mellanox NICs offered better performance and less packet drops. I set the RX and TX sizes with:
sudo ethtool -G rx 8192 tx 8192
I was trying to find the best way to configure this so that it survives reboots and redeploys. I ended up adding a script to cloudinit-userdata in the Juju model defaults that adds a systemd service on each deployed node that runs those commands at each boot.
I’m thinking however that these settings should be configurable elsewhere in an easier manner.
I was wondering at first if MAAS would be the right place, just like we can configure MTU settings in MAAS. But I’d like to know what the Juju team thinks too about if Juju (or a Juju charm maybe?) could support this.
Do you think it makes sense to file a feature request for Juju to support setting Mellanox ring sizes?