I have multiple Macs and I want to update all those macs using a dmg file. From where I can get the dmg file.
And how to update if the minor version difference is more than one. i.e. from 10.10.1 to 10.10.5?
You can get the dmg file from here: https://support.apple.com/downloads/macos
While downloading the dmg please check the system requirement. Because you will need a combo dmg file if you are upgrading from say
On detail page of the dmg there is a
System Requirements button at the bottom, please check the system requirement from there.