Advanced storage and data integrity

One disk dies and the data is gone. One bit flips on a platter and a file quietly rots, and you find out six months later when you read it back. This chapter is about keeping data alive: flexible volumes on top of disks, redundancy through RAID, filesystems that catch corruption on their own.

First LVM, then RAID and its traps, then ZFS and Btrfs with their checksums, and at the end how to pick a filesystem plus a word about the network.

LVM: thin volumes and snapshots

LVM puts a layer of abstraction between disks and filesystems. Physical disks (PVs) join into a volume group (VG), and you carve logical volumes (LVs) out of it. A volume resizes on the fly, with no repartitioning of disks.

A thin pool hands volumes space as they write, not up front. You can crea