How to analyze an unknown Linux(?) machine from scratch?

Question

I am in charge of an office, and want to fix the existing NAS. I have access via SSH and the admin pw. The thing is storing all the office data, so I do not want to change anything on the data side. I googled the model and make (QNAP TS-220) but that does not tell me much about what is running on there today and what versions.

A QNAP forum member calls it QTS and sees is as yet another distribution, which is supposedly widely compatible to Linux but not entirely.

In my SSH console it behaves so far like a linux, the help command gives GNU bash, version 3.2.57, but I never had this weird situation where I do not know what is running - normally it is me who installs the distros on our machines. And my good ole Kofler it not written for such a scenario either.

Since the pretty web-interface of that NAS is partly broken (especially the network setup and totally the DNS setup), I want to have a look and see wheather I can configure some good defaults from my trusted documentation to get the DNS working again.

But for looking up settings or googling help, I need to know what distro this "QTS" is based on, what version I have got, etc. Where do I start on this unknown system please? How can I get some initial "system information" to then look up more specific commands?

Edit: I am thankful for the first helpful answers. I will look into it asap (our NAS is not turned on 25/7 for "Africa reasons"). We cannot assume that the machine is in its original state. So looking up specs etc. is another good first step, but I do not know its entire history and need to know its present condition.

Edit2: You can see below in which answer I found my solution. Now spoiler because the answer is only a link: Our NAS is a very slim or reduced flavour of Linux. This is what I found so far, those are the commands I am/was looking for:

uname -a
Linux Dagobert 3.4.6 #1 Wed Dec 13 01:19:22 CST 2017 armv5tel unknown

lsb_release -idrc
lsb_release: command not found

lscpu
lscpu: command not found

hostname
Dagobert

hostname -I
hostname: invalid option -- I

dmidecode -t system
dmidecode: command not found

Answer 1

I need to know what distro this "QTS" is based on?

What OS does the NAS use?

We have our own software, based off of Linux. All processes are controlled through our web administration management page. Standard Linux 2.6, on the way to migrate to latest stable release.

Source Product information :: NAS :: QNAP

---

How can I get some initial "system information" to then look up more specific commands?

In addition to uname -a, which gives you the kernel version, you can try:

lsb_release -idrc  # distro, version, codename, long release name

Source https://unix.stackexchange.com/questions/1150/how-to-find-information-about-the-system-machine-in-unix

See also this answer.

Answer 2

I own a Synology NAS. It has some ARM processor and its Linux is some embedded Linux variant adapted by Synology which fits that processor.

I found this out by going through the Synology support forum articles, mostly looking for information how to develop and deploy my own applications on that NAS Linux.

The situation for QNAP should be similar. The specs for your model are e.g. here.

Marvell 1.6GHz

This is an ARM cpu as well. There is an Debian Linux available (link), which is probably different from your QNAP's default Linux.

Since the pretty web-interface of that NAS is partly broken (especially the network setup and totally the DNS setup), I want to have a look and see wheather I can configure some good defaults from my trusted documentation to get the DNS working again.

I would consider contacting QNAP's support.

DNS configuration might be standard, but installing software might pose challenges, in case they have their own system to prevent users from fooling around too much with the system.