New to use of Fedora LiveOS media to instantiate VMs using Virtualbox.
When doing this to “try” Fedora and NOT to “install”, when I display my block devices (lsblk)
I see devices 1) loop0, 2) loop1-live-rw, 3) loop1-live-base, & 4) loop2-live-rw.
Items 2), 3), & 4) are of type “dm” which I believe infer that they are LVM related.
In another related posting I read, the following statement was made:
The dm-0 device is one of the virtual block devices created and managed by the device mapper.
If this is true, as for when I type the command “lvdisplay” , why don’t I see these devices listed?
Actually, they are not LVM. The device mapper can be used for a lot of other things.
The setup of the live file system is a bit complicated with stacked mounts and a special setup for creating a file system on top of a read-only file system so you have a limited ability to create new files in this environment.
Thanks for the response. I had an idea that they weren’t LVMs since lvdisplay didn’t show them as such, and neither did the lsblk command. So, what are they? And why do they exist when I do a Fedora LiveOS media “try” and NOT when I do a Fedora LiveOS media “install”? The following link:
states that: The dm-0 device is one of the virtual block devices created and managed by the device mapper. It’s specifically associated with LVM and represents a logical volume within an LVM volume group.
So given this statement is made, maybe you can appreciate some why my confusion on this matter lol!.
Because the Live images were originally designed to work on read-only media such as DVDs. Those extra device mapper layers are necessary to create the writable overlay on top of the read-only base image. When you install the system on a writable device, you don’t need (or want) the extra overhead of the overlay.
Actually, the do. The only difference between “try” and “install” is that the install program (anaconda) is started automatically. The install process is basically copying file by file from the read-only root file system to the install target plus some setup such as creating the file system layout on the target and installing the boot loader. The install procedure works using the read-write overlay root file system created on top of the read-only root file system.