Fundamental questions on backup

[-fun-]

I searched the forum for backup topics but I was a bit lost. There is a lot of discussion on backup setup but I'm still missing some fundamental information: What to backup at all and why. The FreeNAS Guide didn't elaborate on backup that much either.

Can anyone point me to some good reading / forum entries on the following topics:

1st: boot device. I have a USB thumbdrive as a boot medium. I understood that this gets updated with boot menu entries so it gets changes. What else is written to the boot medium? Does it make sense at all to have a backup of this? If it got lost what would be required to get the system running again? Is a copy of the original boot medium sufficient?

2nd: The FreeNAS system itself without any "payload storage". I can download / backup the system configuration and store it in cool dry place. In case I would have to rebuild the system: What is required for this apart from the system configuration database? Is there any backup of a dataset required for this? In the menu within System / System dataset I can select a dataset pool and whether syslog and / or reporting database should be stored there. Is there anything else which gets stored in this way? Can this be backuped and how? Can the system be rebuilt if the syslog and reporting database data would get lost in an emergency?

 

[danb35]

1. On the boot device, there's no reason to back up anything other than the config file. The system will make other changes to files there based on what's in the config file, but you shouldn't manually be doing anything else to the boot device.

2. There isn't really a good way to back up the system logs and the reporting database, but loss of those will not get in the way of bringing the system back up.

 

[CaptainSensible]

Don’t worry about the boot thing, ZFS stays stable.

Always do a backup!

Rsync works.

 

[depasseg]

2. There isn't really a good way to back up the system logs and the reporting database, but loss of those will not get in the way of bringing the system back up.

If you move the system dataset to a pool that is being replicated at the root level, the system dataset will get backed up. I'm not sure what happens in the case of an OS reinstall and backup though (if the system dataset gets overwritten or not). But as you mentioned, it's not really a big deal unless you are really interested in viewing your historical reporting data.

 

[Bidule0hm]

I did reinstall the OS (dying USB stick...) and the .system dataset on the data pool has survived, no problem at all ;)

 

[-fun-]

Things start to get clearer for me, thank you all!

In case of desaster (scenario: all disks and boot media have complete data loss), after repairing any HW damage / recreating an identical HW configuration I can setup the system by preparing a fresh boot medium from a distribution, boot the system from that and restore the system configuration from backup. After that I should have the pool and datasets configured as before, however empty. Historical reporting data as well as logs would have been lost. From this point I would be able to restore backups of the datasets as needed.

Right?

If I would really have to setup a fresh boot medium there is one further question: Let's say the system is running FreeNAS version FreeNAS-9.3-STABLE-201512121950. Can I safely assume that the system configuration backup is compatible with any (earlier or later) FreeNAS-9.3-stable-version? Or would I have to have the exact same version of the distribution ready in the above scenario?

(Sorry if I bother the forum with these questions. Isn't all of this documented somewhere? I find it hard to believe that anyone would use a NAS in a datacenter without complete case-driven step-by-step restore procedures. Well, I don't work in a datacenter and I may as well be paranoid. :-D)

 

[Ericloewe]

Can I safely assume that the system configuration backup is compatible with any (earlier or later

Earlier? No, don't expect it to work. It should work on newer versions, though.