Re: os backup

Hi

Comments embedded

"utkanbir" <hopehope_123_at_yahoo.com> a écrit dans le message de news:f6c90ebe.0502151314.1a07fb6a_at_posting.google.com...
> Hi,
>
> Sorry for the confusion.Let me summarize what i do:
>
> this is my system:
>
> redhat linux 2.1 advanced server
> 4 itanium processors.
> oracle 9.2.0.5 rac with 2 nodes
> ocfs
> emc disk array raid 10
> and this is a datawarehouse system.
> data size is > 1.5TB.
>
>
> 1. stop the dbservers.(i use rac on redhat linux ia64 and have 2 nodes)
> 2. copy all the datafiles to tape.
> 3. start the dbserver.
>

You mean that you shutdown the instances on both nodes? Doing so you perform a cold backup. This is not necessary (although not mandatory either) since the db is in archivelog mode.

To perform an ONLINE backup, you need to do a few things (and the first being to keep the instance up and running) a) for each tablespace:

    alter tablespace xyz begin backup;
    $ backup its datafiles
    alter tablespace xyz end backup;
    alter system backup controlfile to trace; (a good thing to have)     alter system backup controlfile to \somewhere\somefile.xxx     alter system archive log current;
    $ backup the archived log files.
Resulting in no downtime at all. Of course that will take the same amount of time to perform.

> my redo logs are archived periodically and db is in archivelog mode.
>

What do you mean by this? Redo logs will be archved by Oracle (provided that LOG_ARCHIVE_START=TRUE) when they get full. Is something different happening at your site?

And to answer your original question, pls others correct me if I`m wrong, yes you can use the "oracle archived" redo logs to do a point-in-time, or complete, recovery of your database if you restore all the datafiles from one of your backups, mount the database and perform a recovery. You will be prompted for the archived redo logs needed for the recovery. Just don't startup OPEN if you plan on doing a recovery. In this regards using a cold backup is much the same as using an online backup, to recover.

HTH
>
> It takes 12 hours to copy all the data files.
>
> Kind Regards,
> hope
>

-- 
Syltrem

OpenVMS 7.3-1 + Oracle 8.1.7.4
http://pages.infinit.net/syltrem (OpenVMS related web site, en français)
---zulu is not in my email address---


>

> "Syltrem" <syltremzulu_at_videotron.ca> wrote in message

news:<bCnQd.2994$df.109470_at_tor-nn1.netcom.ca>...


> > Since not enough info was given by the OP, nobody here can provide

adequate


> > advice.

> >

> > If the OP is still following this thread, pls provide more info on what

you


> > exactly do.

> >

> > It's not clear if :

> > you use ALTER TABLESPACE BEGIN/END BACKUP

> > and that the db is in archivelog mode

> > and that the redo log files that you backup are the archived, or the

online


> > ones.

> >

> > And remember that while it's a good thing to have a backup strategy,

it's


> > much better to have a recovery strategy, and better again to have proven

> > that it works.

> >

> > Regards,

> >

> > -- 

> > Syltrem

> >

> > OpenVMS 7.3-1 + Oracle 8.1.7.4

> > http://pages.infinit.net/syltrem (OpenVMS related web site, en français)

> > ---zulu is not in my email address---

> > "Ed Stevens" <nospam_at_noway.nohow> a écrit dans le message de

> > news:102211daammhc3imvrpndl841cnu1oue6b_at_4ax.com...

> > > On 14 Feb 2005 05:00:49 -0800, hopehope_123_at_yahoo.com (utkanbir)

> > > wrote:

> > >

> > > >Hi ,

> > > >

> > > >I have a question related to the backup strageties. For some reasons

i


> > > >cant get rman backups but instead i backup data at os level , and

> > > >archive redo logs periodically. I wonder whether it is possible to

use


> > > >my redo log backups for recovery purpose. Is it possible to restore

> > > >some of the archived files from the backup set than apply redo logs ?

> > > >

> > > >Kind Regards,

> > > >tolga

> > >

> > > When you say you're backing up or data at the os level ... are you

> > > simply copying the files without telling Oracle?  Without ALTER

> > > TABLESPACE ... BEGIN BACKUP?  Because if so, your backups are pretty

> > > much worthless.  If I were in your boots, I'd be solving WHY I can't

> > > get rman backups . . . .

> > > Thanks.

> > >

> > > - Ed Stevens

> > >

> > > Cohn's Law: The more time you spend in reporting on what you are

doing,


> > the less time you have to do anything. Stability is achieved when you

spend


> > all your time doing nothing but reporting on the nothing you are doing.