under LVM2, once the file in the snapshot has been modified, an entry to that effect is made in the exception table, and when the (modified, in-snapshot) file is accessed, the blocks read are the modified snapshot blocks, not those from the original volume ("block ... never gets copied from the original volume") LVM-HOWTO 感谢MadHatter
under LVM2, once the file in the snapshot has been modified, an entry to that effect is made in the exception table, and when the (modified, in-snapshot) file is accessed, the blocks read are the modified snapshot blocks, not those from the original volume ("block ... never gets copied from the original volume")LVM-HOWTO
感谢MadHatter