Drive snapshot backup script portable#

Perhaps the most significant difference is how difference is computed. So copy btrfs tree to plain ext4 volume -> you get the same layout as in btrfs without subvolumes.Ĭonversion of btrfs tree to linked lvm volumes, is possible but I dont know a tool that does it.

Drive snapshot backup script portable#

To port plain to lvm you need to bringup lvm there if it doesnt autodetect your vgs.Īll that stuff is autogenerated by bootloader rebuild if you have fstab and crypttab populated.īTRFS Snapshots trees arent directly (integrated to some preinstalled copying solution) portable to other schemes. So any fs that has the feature can contain your system files + metadata.īringup of logical devices is managed by the kernel cmdline. If you forget to copy with preserve then you lose file permissions and dates…īut this whiles it uses filesystem features, doesnt depend on a particular filesystem. If you forget to copy extended attributes (selinux labels) then you need to relabel. It doesnt really matter which filesystem the files are on as long as you dont change the mount tree.

The following command will take a snapshot of the /home subvolume. In order to use the send and the receive commands, it is important to create the snapshot as read-only, and snapshots are writeable by default. To do this, the commands btrfs send and btrfs receive are used. The snapshot can be sent to an external hard drive or to a remote system via SSH (the destination filesystems need to be formatted as Btrfs as well). An interesting feature of snapshots is the ability to send them to another location. By the way, a snapshot on the same disk of the snapshotted subvolume is not an ideal backup strategy: if the hard disk broke, snapshots will be lost as well. You can browse it like a regular directory and recover a copy of a file as it was when the snapshot was performed.

Using snapshots for backupsĪ snapshot resides on the same disk where the subvolume is located. This is a convenient way to perform backups. Added/modified files, and deleted files in the subvolume still reside in the snapshots. Occupied space will increase alongside the data changes in the original subvolume or in the snapshot itself, if it is writeable. However, taking a snapshot is not like performing a rsync or a cp, and a snapshot doesn’t occupy space as soon as it is created.Įditors note: From the BTRFS Wiki – A snapshot is simply a subvolume that shares its data (and metadata) with some other subvolume, using Btrfs’s COW capabilities. Snapshots are an interesting feature of Btrfs.