> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Brian O'Neill > Sent: Sunday, January 06, 2008 8:41 AM > I've seen conflicting definitions of what "Incremental" and > "Differential" are.
Perhaps Legato Networker is different from other commercial products that I've seen, but until I hear otherwise, I'm assuming Legato uses the same terms the same way as the others. I understand that according to the dictionary and layperson understanding of those terms, it's not clear what exactly they mean. They're used a lot (and loosely) in layperson conversation, and that makes it still more confusing. What I'm considering to be the "right" way of thinking, in the context of filesystem backups, is the way of thinking that will help system administrators avoid backup problems. I believe all "official" uses of those terms are consistent with each other. For example, in NTBackup, BackupExec, ARC Brightstor, and Yosemite. All commercial products that I know use the terms "Normal," "Incremental," and "Differential" consistently, and all the documentation describes it consistently and accurately. "Normal" backups copy everything. "Incremental" backups copy everything since the most recent Normal. "Differential" backups copy everything since the most recent Normal or Incremental. Implementations may vary. Some systems use the archive bit. Some systems use "file modified" timestamp. People argue in favor of one implementation or the other, and they all have valid points, but the core idea Normal vs Incremental vs Differential remains the same. _______________________________________________ bblisa mailing list [email protected] http://www.bblisa.org/mailman/listinfo/bblisa
