Hello All,
Thanks very much for your advice. It's appreciated very much. It looks as
if we will be putting forward RMAN with incremental backups and a weekly
full backup as the strategy.
>From Mark's comment, it seems we will have to spend some money on our tape
library as well to ensure we can back it up quickly enough.
Regards
Phil
-----Original Message-----
From: Mark.Donaldson AT cexp DOT com [mailto:Mark.Donaldson AT cexp DOT com]
Sent: 12 August 2004 06:23
To: jkennedy AT qualcomm DOT com; Phil.Stockton AT rs-components DOT com;
veritas-bu AT mailman.eng.auburn DOT edu
Subject: RE: [Veritas-bu] Large Oracle/SAP Database and Netbackup
the only way to split the DB and maintain consistency, at least in oracle,
is to put every tablespace in the DB in hot-backup mode simultaneously,
split the volumes/hypers/whatever, then take the tablespaces out of hot
backup mode.
When each tablespace is placed in HB mode, the associated dbf files are
touched. A unix-style incremental then against these touched files then
grabs the entire DB since every file has an updated timestamp.
An alternative we came up with once was to split the DB, mount the split
mirror on another server, open it with Oracle, then use RMAN to back it up.
When you're done with the backup, you abandone it and snap a new copy for
the next backup. The method offloaded the backup to another server but
still had RMAN and its associated limitations (and powers, FWIW). So - all
the power for incremental backups via RMAN and load moved to another server.
The cost, though, is enough disk for the mirror and the licenses to fire up
Oracle on a new server only for backups. Not worth it, in our opinion.
Might as well buy an off-host data moving appliance instead.
Basically, a unix style, mtime-based, incremental doesn't work on a
database. You still have the problem with consistency on a backed-up open
file, too.
There's a reason that Veritas sells database extensions.
-M
-----Original Message-----
From: Kennedy, Jeffrey [mailto:jkennedy AT qualcomm DOT com]
Sent: Wednesday, August 11, 2004 5:31 PM
To: Donaldson, Mark - Broomfield, CO; Phil.Stockton AT rs-components DOT com;
veritas-bu AT mailman.eng.auburn DOT edu
Subject: RE: [Veritas-bu] Large Oracle/SAP Database and Netbackup
Can't you do incremental backups nightly and use mirror as base? It's
like doing a cold backup and then re-applying logs no? Just send logs
to tape nightly and full mirror backup to tape weekly.
~JK
> -----Original Message-----
> From: Mark.Donaldson AT cexp DOT com [mailto:Mark.Donaldson AT cexp DOT com]
> Sent: Wednesday, August 11, 2004 1:45 PM
> To: Kennedy, Jeffrey; Phil.Stockton AT rs-components DOT com; veritas-
> bu AT mailman.eng.auburn DOT edu
> Subject: RE: [Veritas-bu] Large Oracle/SAP Database and Netbackup
>
> Two reasons for RMAN over split mirror:
>
> 1. Buying 40TB of disk was pretty much out of the question.
>
> 2. split mirrors don't give the opportunity for incremental backups so
you
> have to decide if you're going to backup 20TB every nightly or roll
> forward
> through multiple days.
>
> -M
>
> -----Original Message-----
> From: Kennedy, Jeffrey [mailto:jkennedy AT qualcomm DOT com]
> Sent: Wednesday, August 11, 2004 2:31 PM
> To: Donaldson, Mark - Broomfield, CO; Phil.Stockton AT rs-components DOT com;
> veritas-bu AT mailman.eng.auburn DOT edu
> Subject: RE: [Veritas-bu] Large Oracle/SAP Database and Netbackup
>
>
> With databases that size tape just doesn't seem to be much of an
option
> to me. Why not mirror the stuff and backup the mirror after a break?
>
> I know I know, 20tb is not a small chunk of disk. But if it's
important
> it's worth it. What is the recovery time on a 20tb Oracle db from
tape?
>
> ~JK
>
> > -----Original Message-----
> > From: veritas-bu-admin AT mailman.eng.auburn DOT edu [mailto:veritas-bu-
> > admin AT mailman.eng.auburn DOT edu] On Behalf Of Mark.Donaldson AT cexp
> > DOT com
> > Sent: Wednesday, August 11, 2004 11:24 AM
> > To: Phil.Stockton AT rs-components DOT com;
veritas-bu AT mailman.eng.auburn DOT edu
> > Subject: RE: [Veritas-bu] Large Oracle/SAP Database and Netbackup
> >
> > We did the RMAN thing on our 20TB Oracle DB at my last job.
Solaris,
> NB
> > 4.5, L700 w. LTO-1.
> >
> > There were lots of problems when we went to do our weekly fulls.
Last
> I
> > heard, my replacement is/was working a ticket through VOSS support.
> Turns
> > out that there was a core assumption in Netbackup that the whole DB
> could
> > be
> > backed up in 24 hours. The problem manifested when the RMAN &
> Netbackup
> > catalogs were sync'd - they wouldn't sync right & tracking info
would
> be
> > lost. Sorry - since I left I'm a big short on details.
> >
> > We did weekly full backups & daily incrementals via RMAN. We had to
> > implement restart code in the RMAN script because the smallest fault
> in
> > backups, and easy to get a fault over 20 TB of data transfer, would
> kill
> > the
> > whol backup.
> >
> > We used the RMAN keyword "NOT BACKED UP SINCE '<date>'" to implement
a
> > sort-of point-in-time restart of a failed RMAN backup.
> >
> > Store the start time of the backup script in a variable, capture the
> RMAN
> > return code and loop a restart using the "NOT BACKED UP SINCE"
command
> if
> > it's non-zero. Implement a counter so you don't loop forever in the
> event
> > of a persistent error state. It combats the tape errors, network
> hiccups,
> > etc. pretty well, though.
> >
> > HTH - M
> >
> >
> > -----Original Message-----
> > From: veritas-bu-admin AT mailman.eng.auburn DOT edu
> > [mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu]On Behalf Of Phil
> > Stockton
> > Sent: Wednesday, August 11, 2004 8:17 AM
> > To: 'veritas-bu AT mailman.eng.auburn DOT edu'
> > Subject: [Veritas-bu] Large Oracle/SAP Database and Netbackup
> >
> >
> > Hello Everyone,
> >
> > We are looking at having a 6 terabyte Oracle/SAP database in place.
> >
> > The environment is Solaris.
> >
> > The current tape library is a StorageTek L700.
> >
> > Does anybody have a similar environment? If so, how do you perform
> > backups?. We are a 24/7 business and are not allowed to bring down
> > Oracle/SAP for backups.
> >
> > We are thinking of RMAN and/or snapshot technology combined with
> whatever
> > is
> > SAP orientated.
> >
> > Any advice would be appreciated very much.
> >
> > Regards
> >
> > Phil Stockton and Oracle 9.
> >
> >
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