From b88565f31b0a7874e62a1dc9e97b9c944c11e41f Mon Sep 17 00:00:00 2001
From: Andre Noll
LVM snapshots are based on the CoW optimization -strategy described earlier in the chapter on Unix -Concepts. Creating a snapshot means to create a CoW table of -the given size. Just before a LE of a snapshotted LV is about to be -written to, its contents are copied to a free slot in the CoW -table. This preserves an old version of the LV, the snapshot, which -can later be reconstructed by overlaying the CoW table atop the LV. +
LVM snapshots are based on the CoW optimization strategy described +earlier in the chapter on Unix +Concepts. Creating a snapshot means to create a CoW table of the +given size. Just before a LE of a snapshotted LV is about to be written +to, its contents are copied to a free slot in the CoW table. This +preserves an old version of the LV, the snapshot, which can later be +reconstructed by overlaying the CoW table atop the LV.
Snapshots can be taken from a LV which contains a mounted file system, while applications are actively modifying files. Without coordination -- 2.39.5