What are shadow copies?

[Jimjamesjimothy8]

I'm setting up freenas server and there's a checkbox that says "enable shadow copies" and it's checked by default. should I leave it checked?

[noodle with crab]

Leave it checked. This is basically enabling you to do the backup while using some files at the same time.

[AbsoluteFool]

Shadow copy is simple to understand.. At the most basic level you can think about it as many unfinished files. Maybe documents or other things that are backed up while in progress of being made.

 

If you split my answer into serval small files, where the last file is complete. You will see what shadow copy does.