5.4. Backing up ext2/3/4 File Systems
Procedure 5.1. An Example of ext2/3/4 File System Backup
- All data must be backed up before attempting any kind of restore operation. Data backups should be made on a regular basis. In addition to data, there is configuration information that should be saved, including
/etc/fstaband the output of
fdisk -l. Running an sosreport/sysreport will capture this information and is strongly recommended.
cat /etc/fstabLABEL=/ / ext3 defaults 1 1 LABEL=/boot1 /boot ext3 defaults 1 2 LABEL=/data /data ext3 defaults 0 0 tmpfs /dev/shm tmpfs defaults 0 0 devpts /dev/pts devpts gid=5,mode=620 0 0 sysfs /sys sysfs defaults 0 0 proc /proc proc defaults 0 0 LABEL=SWAP-sda5 swap swap defaults 0 0 /dev/sda6 /backup-files ext3 defaults 0 0
fdisk -lDevice Boot Start End Blocks Id System /dev/sda1 * 1 13 104391 83 Linux /dev/sda2 14 1925 15358140 83 Linux /dev/sda3 1926 3200 10241437+ 83 Linux /dev/sda4 3201 4864 13366080 5 Extended /dev/sda5 3201 3391 1534176 82 Linux swap / Solaris /dev/sda6 3392 4864 11831841 83 LinuxIn this example, we will use the
/dev/sda6partition to save backup files, and we assume that
/dev/sda6is mounted on
- If the partition being backed up is an operating system partition, bootup your system into Single User Mode. This step is not necessary for normal data partitions.
dumpto back up the contents of the partitions:
dump -0uf /backup-files/sda1.dump /dev/sda1
dump -0uf /backup-files/sda2.dump /dev/sda2
dump -0uf /backup-files/sda3.dump /dev/sda3
NoteIf the system has been running for a long time, it is advisable to run
e2fsckon the partitions before backup.
ImportantWhen backing up operating system partitions, the partition must be unmounted.While it is possible to back up an ordinary data partition while it is mounted, it is advisable to unmount it where possible. The results of attempting to back up a mounted data partition can be unpredictable.If you need to back up a mounted file system using
dump, do so when the file system is not under a heavy load. The more activity is happening on the file system when backing up, the higher the risk of backup corruption is.If you want to do a remote backup, you can use both ssh or configure a non-password login:
dump -0u -f - /dev/sda1 | ssh firstname.lastname@example.org dd of=/tmp/sda1.dump
NoteIf using standard redirection, the
-foption must be passed separately.