Please follow the below template, it will help us to help you!
*If you are Experiencing issues with a Pi-hole install that has non-standard elements (e.g you are using nginx instead of lighttpd, or there is some other aspect of your install that is customised) -
I've installed Pihole using a Virtualized Server.
Installed OS in this instance is Ubuntu 22.04
4 Vcores / 2 GB Ram / 20 Gb SSD
I've also installed Unboud and set an exception for some T-Mobile domains, needed for Wifi calling
Expected Behaviour:
DNS resultion should be working "normal" - So if asking for a website it should open.
Actual Behaviour:
Sometimes when i open a new web page - I get an DNS Error. If I open the page some seconds later - everythinf is working dine
Also i see some strange things happen with my RAM
The command "free -h" shows the follwing:
total used free shared buff/cache available
Mem: 2.0Gi 63Mi 1.9Gi 9.0Mi 20Mi 1.9Gi
Swap: 2.0Gi 0.0Ki 2.0Gi
=> This tells me, that there should no bottelneck with my RAM
but if i use "htop"
the Ram Usage is nearly 100%
-> It is written " MEM : 16.0Z / 2.00G"
But there is no task, which is taking so much ram.
There is nothing in your debug log that would hint at memory being an issue.
In particular, there is no warning message under Pi-hole diagnosis messages.
Pi-hole would notice and log when your system was nearing RAM exhaustion.
Your debug log shows your system is lacking upstream IPv6 connectivity, though your network seems aware of a public IPv6 prefix.
That could have had an impact on your observation of sporadic slow DNS queries if Pi-hole would be configured for an IPv6 upstream - but your Pi-hole is using only IPv4 (which is perfectly fine).
I also note that you are using unbound as one of Pi-hole's upstreams:
(Likely unrelated, there also seems to be a spelling error for the Conditional Forwarding local domain (it's missing the final 'g').)
That is unusual, as it would leak your DNS requests to DNS_1 and DNS_2.
If you'd want to benefit from using unbound as a recursive resolver, then unbound should be Pi-hole's only upstream.
As an initial full recursion can be expected to take longer than just querying a public resolver, this may affect your resolution speed at times when unbound is picked as an upstream every now and then.
Usually, unbound would cache DNS replies, so subsequent DNS requests could be answered instantaneously. However, as your unbound only sees a farction of the DNS requests, it probably would struggle to apply the best caching strategy for yor network.
You should opt to either use unbound or public DNS resolvers.
I believe @Bucking_Horn is referring to the addresses you have set up under Settings/DNS. For a typical Unbound setup, you want to have none of the the DNS servers listed on the left column checked and only your loopback IP with Unbound port listed under the right column.
But based on your final statement, you may have already figured that out. Setting the options as above will correct the setup variables mentioned before.
