Thank you @lindy65 . Sorry if I didn’t explain correctly.
I’ve already searched in those documents.
But they talk about upgrading mattermost, or they talk about installing on ubuntu 14 or ubuntu 16.
I didn’t find any doc even with this search: “ubuntu upgrading”
So the question is: does anybody upgraded linux from 14.x to 16.x and had problems ?
Thank you in advance.
(ps here Ubuntu 16.04 support they talk about docs, not effects on upgrading o.s.)