[linux-lvm] how to copy a snapshot, or restore snapshot without deleting it

[Davis, Matthew]

Hi,

I want to restore a snapshot without deleting the snapshot.

My use case is that I'm experimenting with a lot of different drivers, kernel modules, and file modifications all over my machine.
I want to 
1. take a snapshot of the working system
2. make changes
3. restore the snapshot (` sudo lvconvert --merge /dev/ubuntu-vg/$SNAPSHOT` then reboot)
4. make new changes
5. restore to the snapshot again

The problem is that step 3 deletes the snapshot, so step 5 fails.

My current workaround is:
1. take a snapshot of the working system
2. make changes
3. restore the snapshot (` sudo lvconvert --merge /dev/ubuntu-vg/$SNAPSHOT` then reboot)
4. Wait 1.5 hours, without making any changes to the machine
5. Take a new snapshot, with the same name as the original
6. make new changes
7. restore to the snapshot

This is not great because:
* I sometimes forget to do step 5
* I can't take a snapshot of the volume while it is still merging. This takes 1.5 hours. I want to be able to restore my snapshots multiple times per day


Is there a flag I can add to `lvconvert` to make it not delete the snapshot?
Alternatively, is there a way I can make a copy of the snapshot before I restore it?

It looks like someone else asked this question 10 years ago. 
https://www.redhat.com/archives/linux-lvm/2008-November/msg00000.html
Has this problem been solved since then?

Thanks,
Matt Davis

Technical Specialist
Telstra | Product Strategy & Innovation - Telstra Labs | Programmable Infrastructure
E  Matthew.Davis.2 at team.telstra.com