On 1/6/21 5:51 PM, Bernhard M. Wiedemann wrote:
On 06/01/2021 14.47, Michael Ströder wrote:
Does this count as factory-reset? And in which situation do you need such a factory-reset (for whatever definition of factory-reset)?
Before I joined SUSE, I built video-player hardware appliances based on Debian and they had such a factory reset implemented with aufs to allow people to get a system back into a defined config state. Comes handy for all kind of hardware that is rented out.
So IMHO this was a rather constrained setup, much under control of the vendor and not subject to change by the average sys admin.
If one needs automation one should implement real automation and not rely on admin changes in /etc being restored.
I have used chef and salt a lot over the last years and there is always one shortcoming: They are great at setting up things, but if you update your state descriptions to no more install + configure + run foo, it will just leave foo on the systems.
Yes, that's a real deficiency of most config management *code*.
Starting from scratch is one way out, but can be rather slow.
In case of your video-player hardware appliance example users will probably expect a factory reset to go really quickly (up to a minute or so). But when talking about server service setups 15 to 30 min. is acceptable. The most important thing in this case is that you don't need to do something manually.
Also not so easy, if you have relevant data on the machine. But cleaning /var would also remove database files or video files in your example. How to deal with that?
In case of HA for databases or file storage you need to setup instant replication to backup instances anyway. Ciao, Michael.