A Running Image

[BryanOB]

Hello all,
I'm new to your group, and this is my first post.
I have read the documentation, perused the forums and other places, but just couldn't get a definitive answer to my question.

I know that a FreeNAS installation takes control of the device, on which it is installed.
But, what exactly is a "Running Image"?

Thanks for the reply,
BryanOB

 

[peterh]

I don't know from which context you speak of "running image" but the traditional
interpretation is :
- image == a runnable executable,output from "ld", when saved in a file
in a file on some media called "program"
the name "image" refers to the fact that it's an image of the core when the program is loaded
- running image == same as above currently executing in core

 

[BryanOB]

Peterh,

Thanks for trying to provide an explanation.
It's probably just a matter of semantics, an the way I interpret the English language. That coupled with the fact that I'm learning more about how Linux works; having come from a Windows environment.

I understand the concept of an image file, being an exact copy of tracks as they were laid out on the media; a picture if you will.
Clarifying the context:

I read in the FreeNAS Community Spotlight page <http://www.freenas.org/community/spotlight/item/sharing-files-with-freenas-8>, and I quote:

"In the latest release, FreeNAS uses a running image, which takes over the entire target disk, regardless of its size. FreeNAS requires at least 2GB for installation, and during installation it creates two partitions. One partition holds the current installation, and the other is used to store newer FreeNAS releases, which are again running images. The availability of all running image makes it easier to upgrade..."

I didn't understand the context of a "running image" as was used in the article. I was trying to determine...

1) Is the image file that was written to the Compact Flash card, entirely loaded into RAM on boot up, and therefore, the OS never accesses the CF again, unless it does so for storing or reading configuration data?

2) Does "running image" mean that newer FreeNAS releases gets installed on the fly, thereby not requiring the system to be rebooted?

3) Is there a direct correlation between a running image, and FreeNAS taking over the entire target disk, or there was no correlation at all, and that was just how FreeNAS was design to work (i.e take over the target disk).