Exploring Linux Backup Utilities

Edit: I still really like Storix. Relax and Recover is pretty popular as well.

Originally posted April 2005 by IBM Systems Magazine

I’ve been an AIX administrator for a while now, and the mksysb and sysback utilities, which allow me to do bare-metal restores and return my machines to the state they were in when I last performed a backup, have spoiled me. As I’ve worked more with Linux machines, I’ve been bothered that they lack the equivalent utilities.

This is not to say that backup options don’t exist at all for Linux machines. Some use the dd command to copy the entire disk. Many have written scripts that use the UNIX shell command tape archive (tar) to run the open-source utility rsync, which duplicates data across directories, file systems or networked computers.

Others use the Advanced Maryland Automatic Network Disk Archiver (AMANDA) or dump. According to the University of Maryland’s AMANDA Web site, AMANDA lets a LAN administrator, “set up a single master backup server to back up multiple hosts to a single, large capacity tape drive.” AMANDA can use native dump facilities to do this.

Dump itself creates an archive directory and an access interface across whole file systems. It lets you build in specifications for when to run the dump, but it isn’t for everyone because it might not support all the file systems you need.

Two more advanced archive tactics are the cpio and afio utilities, both of which are considered to have better consistency and integrity than tar, with which they’re backward compatible. However, they may require a lot of time reading the man page and other resources to use them effectively.

In my Google search, I also came across “Linux Complete Backup and Recovery HOWTO”, run by software engineer Charles Curley, a 25-year veteran of the computing industry. This site provides instructions for using a backup and restore methods for several Linux products.

The solutions I’ve talked about can be more attractive to Linux users because they’re free. Each of them also makes you build a minimal system before you can restore the rest of your system. When I argue AIX versus Linux, bare-metal restores is usually something I can bring up that Linux advocates can’t address. So I started wondering if there was a tool that was exactly like mksysb or sysback, where you could boot up and restore your machine in one step. The only tool I found–Storix–offers a free personal edition and a free demo edition that you can use to test it with, but if you want the full benefits of this software, you’ll need to buy a license. It isn’t free software, and that may deter some in the Linux community.

Storix offers functionality similar to tools such as tar and secure shell (SSH) for backing up a machine over the network to a remote machine or tape drive, a local file, a tape drive or a USB disk drive. The restore is where Storix has a different functionality, working as a true bare-metal restore. While other tools require you to reload the OS before running the restore process, Storix reloads the entire machine from the bootable CD, eliminating time spent configuring user IDs, groups, permissions, file systems, applications etc. There are far too many places to inadvertently leave out something that has already been fixed when you rely on people to go around rebuilding machines when the hard drive dies. Bare-metal restores may help users feel more comfortable about making changes to the existing system because they can return the machine directly to its previous state.

There are as many methods to back up your machine as there are reasons to choose them. So go ahead and destroy your machine. Just make sure you have a good backup plan before you do so, no matter which tool you choose.