I need help, I recently had to reinstall Pi-Hole on my Pi due to a critical SD failure.
It turns out that since I started with Home Assistant and Proxmox as well, I created users and passwords with an easy-to-remember trend.
But although I have access to the Pi-Hole Web UI console, when I go to open the SSH console, it turns out that either the username or the password, or both, are written down wrong or I don't understand what I'm doing wrong.
Can someone tell me which user is governing access through the command console so I can be sure that the note is correct and perhaps reset the password (something I can't do either).
There is no specific user designated for Pi-hole. Any user with sudo privileges can interact with the pihole command and other related system components. You can use an approach like this to attempt a recovery if you're locked out.
I'm in one of those days when nothing comes out of what you touch in computing and I was left blank until I realized that if you start Raspberry OS with HDMI, the visual interface appears. Solved by resetting the password.
I take this opportunity to ask (with these tests I have verified it), if the Raspberry hangs or is turned off, I will be left without internet, is the solution for this to set up a secondary DNS like Google's? Because what will stop the requests from showing ads if I do that? Or in order first does everything go through the DNS configured for Pi-Hole?
No.
This is not how DNS works. There is no real order between "primary" and "secondary".
If you set another DNS server, your devices will use both IPs (devices will choose one between both IPs in every query).
The result would be frustating, because some queries will be sent to Google, bypassing Pi-hole.
EDIT:
If you want an alternative DNS server, the best solution would be to install a second Pi-hole, like chrislph recommends below.
If you already have another "always on" device on your network (another Raspberry Pi, a server, a NAS, etc.), you can install Pi-hole on that device (bare metal or in a docker container).
Pi-hole is very stable in and of itself, so it's very much install and forget. However if something else running on the OS might cause stability problems, or the Pi could be turned off, I'd be inclined to solve that by having a dedicated Pi-hole device.
As the network's DNS server it's too important to be considered something that might be okay or hopefully won't be turned off. A wifi-connected Pi Zero W works well for a low-cost dedicated Pi-hole, and you can get ethernet adapters for them if desired.
Very interesting proposal. But what advantage does it offer over a Pi3b that I use now? In the end the "corrupt SD" factor could still happen, right? which only leaves me the window of acquiring a very good quality SD like those used in photography to dedicate to this (absurd waste of storage), and I don't know if I connect it via Wi-Fi, if the reaction speed when resolving requests It's a little worse.
You mentioned other services, so I'm assuming that other things are running on your 3B alongside Pi-hole, and it's those that you're worried might impact Pi-hole. A dedicated Pi just means you can separate the environments so that Pi-hole has its own one, if that's the concern.
As jfb says, it also means you have a spare Pi, so even if one fails (card, PSU, software) you can manually bring up the same services on the other.
I'm sorry, I guess it was a translation error. The only problem was being manipulating the PI for some reason and trying to consult from the PC some documentation, so as not to have to restart the router when changing the DNS I was left without internet.
But it is not a matter of failures or that something else runs on the PI3b, it is only pi-hole running on Raspberry OS.
But of course I will take into account all these tips, I also have Chuwi Larkbox running Proxmox and Home Assistant and a QNAP NAS, so both options would give the possibility to perform a second alternative Pi-Hole as secondary DNS.
