[Veritas-bu] What if differential doesn't have a full backup?
2001-10-18 11:43:47
Subject: |
[Veritas-bu] What if differential doesn't have a full backup? |
From: |
larry.kingery AT veritas DOT com (Larry Kingery) |
Date: |
Thu, 18 Oct 2001 11:43:47 -0400 (EDT) |
On unix, the differential backup is based on the beginning of the last
backup in the same class. So if there's no full, then everything will
"have changed" and you'll effectively get a full backup. That is to
say that everything will be backed up, it's not really a full backup
(I make the clarification mostly because not having a full may affect
subsequent cumulative backups).
On windows, I don't know how or when the archive bit is used, but I
think it was just discussed thoroughly.
Sixbury, Dan writes:
> I just ran across two classes that run on the same server. One class has
> one schedule that does a full backup of multiple file systems that contain
> oracle data in them. This is used for a cold oracle backup.
>
> Another class is for the same server but is doing all of the file systems
> that are not included in the first class. However, this backup is a
> differential incremental.
>
> 1. Doesn't a full backup have to be associated with the class, or will
> NetBackup realize that another class is performing a full backup?
>
> 2. Since the differential incremental has different file systems from the
> full backup, I would assume that the first time the differential incremental
> is run that it would perform a full backup of all of its selected file
> systems and then the rest of the week pick up only the changes. Is that the
> correct assumption?
>
> My only concern would be that something is not getting backed up with these
> two classes even though all file systems are selected between the two
> classes and schedules. I guess one of the questions here would be if you
> run a differential incremental backup and haven't run a full backup, does
> that mean the first differential is equivalent to a full backup or does it
> mean that you have put yourself into an unrecoverable situation? And how
> does having different files selected for your full backup and for your
> differential incremental backup affect your backup/recovery?
>
> My only disclaimer is that I didn't set these two classes up. ;-)
>
> thanks,
> Dan
> _______________________________________________
> Veritas-bu maillist - Veritas-bu AT mailman.eng.auburn DOT edu
> http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
--
Larry Kingery
Don't anthropomorphize computers -- they don't like it.
|
|
|