[CentOS] LVM and thin snapshots

Fri Sep 27 09:39:24 UTC 2019
Georgios <gpdsbe+centos at mailbox.org>

Hi there!

Im new here.

Im trying to install Centos 8 on my laptop. I also want to have a
contingency plan in case something brakes.

My first thoughts were to use LVM.

The idea is that i would take multiple snapshots of the system during
the day/week and will keep them for a short time.

I read RHEL documentation about how lvm works and pretty much understand
how to manage the above scenario with LVM snapshots and encryption.
If i understood lvm snapshots will cause delay the system after multiple
snapshots.  The best way to avoid it is using thin snapshots.

At rhel documentation it says that is possible for a non thin volume to
get a thin snapshots.

[Correct me if my above assumptions are wrong or if there is a better
solution for my purpose.]

So i created a group with 3 volumes groups and one thin pool.

Im trying to take a snapshot and i get the message.

"Cannot use writable LV as the external origin."

I read somewhere that i should change it to read only and then take a
snapshot. Although that would be a problem i just try it to see if it
works. Then i got the message

"Cannot use active LV for the external origin"

Any ideas???

Thanks in advance