Many commercial Unix vendors have enhanced backup tools with decent error recovery built in. AIX has the aptly named backup and restore, while HP-UX has fbackup and frecover. Those, too, unfortunately, lack speed and user-friendliness, although, in the case of these vendors, menu-driven backup tools are provided through system administration menus.
To address this problem, many commercial vendors have entered partnerships with third-party tools to be delivered as part of their OS. Sometimes these tools are trial versions that require full licensing for continued use. Freeware tools are also available, particularly in the case of Linux. In fact, for the administrators running Linux, the field of choice is increasing at an incredible pace. Keep in mind, however, that many GNU tools will compile and run just fine on commercial Unixes.
What are the options and how do you decide what to use? Why pay for a package when others are available for the cost of a download?
I'll tell you a secret. Some pretty slick commercial packages are also available free of charge, provided that you use them in non-profit, non-commercial environments. For example, Enhanced Software Technologies makes BRU (stands for "Backup and Restore Utility), an incredibly easy-to-use, yet powerful and reliable backup utility. The difference is that the personal (or free) edition will not back up remotely mounted drives or Samba shares, or allow the use of remote tape drives. If you are running a single server at home, this is still a pretty good deal. Another contender for slick and powerful, Arkeia from Knox Software, will let you back up two Windows 9x clients. Another free backup utility that provides great commercial features like indexes stored at the beginning of the tape and graphical search tools is taper, which is designed specifically for Linux.
Free tools offer the hard-to-beat argument of low price while still providing reliability. Commercial tools generally provide maturity and easy to use interfaces. Multiplatform support is another issue. If you need to work with a variety of operating systems and you want to maintain a common backup strategy and set of tools across your enterprise, you will likely have to spend the money. For instance, imagine a network of several Windows workstations, a Solaris Web server, an AIX machine, a DGUX server, a couple of NT boxes, and a Novell server. This kind of mixed environment is not unusual, so many commercial vendors will take this into account. For instance, Legato provides software that works in precisely this kind of environment with a central server that backs up remote clients across the network. So does Arkeia, mentioned earlier. Furthermore, some of these advanced tools enforce good tape rotation practices with strict, built-in rule sets.
Even in this complex environment, it's not so cut and dry. Enter AMANDA, the "Advanced Maryland Automated Network Disk Archiver," a freeware tool developed at the University of Maryland. With AMANDA, you set up a central server with a high-capacity tape drive to back up multiple network connected hosts. With Samba, AMANDA can also back up Windows 9x workstations. This is a powerful, multiplatform, network backup solution that costs nothing other than the time to download, compile, and learn.
Some of these network packages use multiple network streams so that several machines back up at the same time. Sure, it sounds great, but there are costs. In the case of a commercial package, there are the obvious software costs of per-client licensing, but that's only one consideration. What about the drain on your network? If you back up during the day or use multiple network streams to do the backup, you may find network applications to be quite slow. Does your network backup solution suddenly require that you invest in a fibre network to take up the slack? What about data recovery, the very reason for backups in the first place? When the inevitable happens and you must recover from a crash, you will likely need to rebuild a working, networked system before you can even consider getting at your data. Many large-scale network backup solutions are better at providing access to individual files than completely restoring a crashed server. You may still need to do regular OS backups and maintain snapshot configurations of your system so that you can re-create filesystems, devices, network addressing, and so on.