[CentOS] LVM and Backups

Hey there, I'm testing LVM snapshot to make backups and I've some questions about snapshot lvm.

In my test case I have httpd, postgresql db and a dataset on a VM.

Running a backup I follow this steps:

1) Stop httpd 2) Create lvm snapshot on the dataset 3) Backup database 4) restart httpd (to avoid more downtime) 5) mount the snapshot and execute backup 6) umount and remove the snapshot

I think that this could be fine (if not please correct me)

Now when bacula performs the backup what happen if bacula are copying a specified file and this specified file is modified?

Bacula will copy the right file using inode (this will copy the wrong file?) or copy entire file located in the snapshot?

Thanks in advance.