On Mon, 14 Feb 2000, mark wrote:
supported. I liked the fact that both QR and Veritas used an ISO standard tar format for the backup. This ruled Legato out early, since they use
Hmmm, I suspect from what I've learned from Veritas and others, that you don't see tar format on the tapes used for the basic backups. The reasoning being that the backup software usually interleaves several streams of data from clients to ensure streaming onto tapes (to extend tape lifetimes as well as reduce the overall backup window). Cloning the tapes in some manner allows the backup software to reduce the chance of data loss AND also to rationalize the interleaving so you do get tape files with coherent tar format inside.. but some folks don't clone tapes, so they may well never get tar-readable tapes.
My understanding of Budtool and Quick Restore was that you could pull tar files off of the tape directly. Generally, the desire for this ability is:
1) if the machine with the backup software goes down, you can still do recoveries, and 2) you can restore to differing systems.
I will grant that the Veritas solution of interleaving streams does sound well thought out and probably more efficient, but from an admin's perspective, you have to figure some day the worst will happen.
I'd be happy to hear otherwise, but I wouldn't place too much value in that ISO standard tar formatting. I have to say that when I first heard, from Veritas Reps trying to sell their product to me, that the guys at CDC had nobbled gnu tar into an enterprise-class backup product (GPL notwithstanding) I just chuckled.
Reminds me of Microsoft's argument against solaris : "Sun is trying to resurrect the 1960s-era mainframe paradigm and return computing to old-style timesharing." (www.dot-truth.com) Amazing how marketing appeals to feelings, not empirical data.
an enterprise-class backup product that manages every detail for you, the value of personally being able to grub through a tape using tar begins to pale a bit.
Until the system with the backup-product fails....
But that all said, your comments are appreciated and gives me food for thought. I guess it weighs in as one of the older Unix paradoxes - ease vs. utility (can't think of a better way to phrase that). Sure, who wouldn't want the easiest to use backup software? But from an admin perspective, we have to be able to pick up the pieces if it all explodes and put it back together ASAP.
----------- Jay Orr Systems Administrator Fujitsu Nexion Inc. St. Louis, MO