Re: Block Level Incremental Backups

It's over a year since someone tried to
sell me BLIB, so I may be out of date,
but

1. BLIB is a Veritas thing, which you could set up to do any style of Veritas file-system incremental backup that you want to.
2. Rman is a pure Oracle thing that has a facility for generating incremental backup images, irrespective of the environment that Oracle is working in.
3. However - if you buy the appropriate licences from Veritas, they will include a module which allows rman to become BLIB aware, giving you the benefits of both systems at once.

The drawbacks are:

1. BLIB takes a lot of disk space - but this may not be a problem, since disks are too big these days, and you need some excuse to stop people from using too much of a disk for the database
2. rman does its incremental backup by checking the SCN on every single (read write) block of the database, so the read overhead is still there, even though the potential saving on writes is high.

--
Jonathan Lewis
http://www.jlcomp.demon.co.uk

Host to The Co-Operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html

Author of:
Practical Oracle 8i: Building Efficient Databases

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Use spare CPU to assist in cancer research.

Steve Mckee wrote in message
<7926e63f.0112030725.9c5297d_at_posting.google.com>...


>Hi,

>

>We are developing a backup solution for our database product.

>The product runs on Solars 8, Oracle 8.1.7, and uses

>the Veritas Database Edition for Oracle. All file systems

>are VXFS and we are using Quick I/O files for the database files.

>

>From what I understand, there seems to be 2 different

>ways of performing incremental backs:

>

>    o one using RMAN

>    o one using the Block Level Incremental Backup (BLIB)

>      from Veritas.

>

>

>Question 1:

>

>Am I correct when I say that these are 2 separate ways

>of performing incremental backups? Or does one somehow use the other.

>

>Question 2:

>

>Which is better?  What are the advantages/disadvantages of each.

>

>

>

>Thanks

>

>Steve