Re: [linux-lvm] Using LVM to snapshot Oracle

[Klaus Strebel <klaus.strebel@gmx.net>]

Luca Berra schrieb:
> On Mon, Feb 20, 2006 at 11:05:32PM +0100, Luca Berra wrote:
> to clarify:
>> you can do hot backup, but you will need to tell oracle you are doing
>> so:
>>
>> you will need to have oracle in archive log mode
>>
>> you will need to manually set all tablespaces in backup mode:
>> alter tablespace XXX begin backup; (for all tablespaces)
>> alter system switch logfile;
> the snapshot creation part goes here
> 
> NO >do your backup including the archive logs
> 
>> alter tablespace XXX end backup; (for all tablespaces)
> 
> do your backup here including the archive logs
> destroy the snapshot here.
> 
>> it is a simple sql script to code
>>
> 
Hi Mitchell, hi Luca,

well, despite i prefer using RMAN ( since 9iR2 it's once configured and 
then you can always do your backup with a simple 'backup database' ) but 
you need your database running in archived mode, which brings additional 
space and backup needs.

The way Luca describes for a online-backup is the usual way that's 
working since Oracle 7 ( or even 6, but just work with Oracle since 7.0 
;-) ), but i think, if all ( really all !) files are on the same 
snapshout and the snapshot is big enough( ;-) ), you should make a 
logswitch, create a readonly snapshot, copy all the files ( including 
control-files, and redo-logs ) and remove the snapshot. You can then 
carefully try to use these files to restore the database. If you have 
enough diskspace, you can shutdown your instance, rename all the files ( 
again incl. control-files and redo-logs ), restore the copies from the 
snapshot and start the database carefully ( startup nomount; alter 
database mount; select file#, name, status from v$datafile; -> all file 
should be in status system or online ; alter database open; -> up again ).
I have nither the time nor the resources to test this on my own. But you 
can share your results with us :-)

Ciao
Klaus


-- 
Mit freundlichen Gr�ssen / best regards

Klaus Strebel, Dipl.-Inform. (FH), mailto:klaus.strebel@gmx.net

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