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:
- 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.
Interleaving (multiplexing is the term in NetBackup) is optional in NetBackup. You can turn it off for any class.
NetBackup NDMP does NOT use multiplexing. Also note that for NDMP the tape format is determined by the NDMP server vendor.
__________________________________________________________________________ Steve Kappel steve.kappel@veritas.com VERITAS Software steve.kappel@iname.com (Personal)
Steve,
Are there any plans / ideas from Veritas on improving backup/restore times of filers ? It seems that the tape/backup s/w is not keeping up well with the filers' huge sizes ?
What is the best configuration that can give us best performance ?
Eyal, Motorola.
Steve Kappel 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:
- 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.
Interleaving (multiplexing is the term in NetBackup) is optional in NetBackup. You can turn it off for any class.
NetBackup NDMP does NOT use multiplexing. Also note that for NDMP the tape format is determined by the NDMP server vendor.
Steve Kappel steve.kappel@veritas.com VERITAS Software steve.kappel@iname.com (Personal)
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Eyal Traitel -
Steve Kappel