Make Backups using LVM snapshots

With Logical Volume Manager, backups can be taken using snapshots.

in this example the resources are:

Volume Group = vg1

Logical Volume1 = /dev/vg1/data 100M /data             //data disk

Logical Volume2 = /dev/vg1/backup 100M /backup    //backup disk

Snapshot Volume = /dev/vg1/snap 100M /snap          //snapshot disk

Disk Name = /dev/sdb                                            //physical disk

First we are going to create a partition.

# fdisk /dev/sdb

new partition: n

primary partition: p

partition number: 1

then the size of the disk will be specified.

Now we create physical volume and logical volumes.

# pvcreate /dev/sdb1

# vgcreate vg1 /dev/sdb1

# lvcreate -L 100M -n data vg1

# lvcreate -L 200M -n backup vg1

Logical volumes will be formatted with ext3 file system format.

# mkfs.ext3 /dev/vg1/data

# mkfs.ext3 /dev/vg1/backup

Logical volumes will be mounted.

# mkdir /data

# mkdir /backup

# mount /dev/vg1/data /data

# mount /dev/vg1/backup /backup

Create some test data.

# cd /data

# mkdir deneme

# touch test

Physical and logical volumes can be listed.

# pvdisplay

# lvdisplay

Now we can take a snapshot.

# lvcreate -L 100M -s -n snap /dev/vg1/data

To see the snapshot volume.

# lvdisplay

Mount the snapshot volume.

# mkdir /snap

# mount /dev/vg1/snap /snap

Copy and compress the snapshot volume.

# tar -czvf /backup/backup.tar.gz /snap

Backup is taken so snapshot is no longer needed.

# umount /snap

# lvremove /dev/vg1/snap