On Dec 17, 2010, at 8:10 AM, Mark Woodward wrote: > > My question for you guys is what do you *want* in a backup. We've all > used these feature laden things that are out there, 99% of which is > pointless. What are "must haves?" What is something you've wanted but > can't find? What are features that are most pointless and why?
Backups must be simple to make and simple to maintain, and they must be easily automated. Disaster recovery must be simple. I need to be able to put a tape in the drive, type a command or three, and undump the backup to the file system. In particular, I need to be able to do this from a live disc or netboot. Individual file restores must be as simple as a full system restore. Anything that facilitates these requirements is good. Time Machine is an example of a "rich" backup system that meets these requirements. Creating backups is simple: plug in a drive, click "yes" when OS X asks to use it for Time Machine. Automation is automatic: Time Machine makes an incremental backup every hour. Disaster recovery is simple: boot the OS X installation media, tell it to restore from a Time Machine backup, sit back and let it go. Individual restores are equally simple, and Time Machine offers two nearly identical methods. For files, open the containing directory (folder) in Finder, Enter Time Machine from the Time Machine menulet, browse for when, select your files, and restore. For applications that are aware of Time Machine, such as Mail and Address Book, repeat the same process but from the applications themselves rather than Finder. Anything that can get in the way of these requirements is bad. Anything that complicates restoration or makes disaster recovery take longer than booting a disc and undumping a tape is bad. Examples include Legato Networker and Windows Backup. The former requires catalog files to do any data restores, and these catalogs are not stored with the backup data in an accessible form. If you lose a catalog or a catalog is corrupted then you have to scan the entire dump set to rebuild the catalog, which takes as long as a restore would, and only then can it be restored (caveat: this is 15 year old data; Legato could have fixed this glaring flaw). The latter requires a full OS installation on the hardware being restored before a backup can be restored onto it, and the result is not a perfect 1:1 restoration of the original. Everything else is nice to have. Some nice to have things, such as incremental backups, data compression and encryption, are mandatory for specific environments. I do not consider them to be universally required in a backup system. --Rich P. _______________________________________________ Discuss mailing list [email protected] http://lists.blu.org/mailman/listinfo/discuss
