Re: archivelog backup and its files

Chris,

Were you sure about which file to be copied at the :
"(from the os copy the file somewhere)"
stage ?

When you do an ALTER TABLESPACE <tablespace_name> BEGIN BACKUP you can backup the datafiles belonging to that tablespace. Issue an ALTER TABLESPACE <tablespace_name> END BACKUP after you have copied _all_ the files in that tablespace.

The Archived Redo Logs will be continually generated in the log_archive_dest --- one archive file for each "filled" redo log. You should always do an ALTER SYSTEM SWITCH LOGFILE at the end of the backup to ensure that you have all the redo generated since the backup began.

Hemant K Chitale

"Fraser McCallum" <fmcc_at_NOSPAModbaguru.com> wrote in message news:q4c68.79499$ru2.917130_at_NewsReader...
> Chris,
>
> You are doing nothing wrong.
>
> The archivelog files are created as copies of the old online log files
once
> oracle is finished with them. No archivelog files will be created until
> after a log file is switched, either automatically by oracle or manually
be
> you. During an online backup additional information that is needed by
Oracle
> during a restore is written to the log files, without this information you
> will not be able to recover. However you can't backup an online logfile
> while the database is open and depending on how busy your system is some
of
> the information may have been archived while your backup was in progress.
> That's why HJR's procedure has an "alter system switch logfile;" at the
end
> to move the last lot of required information into an archivelog file. Thus
> your very last step should be to back up all the needed archive log files,
> starting with the most recent one that existed prior to the backup
starting
> and ending with the last one you created with your switch logfile command.
>
> Kind Regards
>
> Fraser McCallum
> MVP Oracle Administration
> www.brainbench.com
>
> "obakesan" <cjundieseastwd_at_powerup.com.au> wrote in message
> news:tq968.6782$T4.65733_at_nnrp.gol.com...
> > HiYa folks
> >
> > I am having some trouble with the basics of back up and recovery
> > and since this is the first time I have done any of this I thought
> > that I would ask a simple question.
> >
> > I have been following the guidance of the document by HJR
> > who suggests that a hot backup sequence be something like this
> > (from SQLPlus)
> > alter tablespace mydata begin backup;
> >
> > (from the os copy the file somewhere)
> >
> > (from SQLPlus)
> > alter tablespace mydata end backup;
> > alter system switch logfile;
> >
> >
> >
> >
> > now, my problem is this, I have just changed a new database to be in
> > archivelog mode by using the following
> > sqlplus /nolog
> > SQL>
> > SQL>startup nomount
> > SQL>alter database mount
> > SQL>alter database archivelog
> > SQL>alter database open
> > SQL>alter system arvhive log start
> >
> > and of course edit the file init$ORACLE_SID.ora to add the lines
> >
> > log_archive_start = true
> > log_archive_dest = "/u01/app/oracle/admin/DEV/arch"
> > log_archive_format = arch_%t_%s.arc
> >
> > now my problem is, that there is no file in the log archive dest after
> > I have done this procedure, have I done something wrong?
> >
> > I wasnt sure, so I tried issuing the command
> > alter tablespace mydata begin backup;
> >
> > which didn't make any file either
> >
> > I then took the next step of
> > alter tablespace mydata end backup;
> >
> > and then
> > alter system switch logfile;
> >
> > and lo and behold a file appears in the location.
> >
> > so my question is "is his order right or am I doing something wrong?"
> >
> > do I have to change file first, then backup that changed file??
> >
> >
> > Thanks folks
> >
> >
> > See Ya
> >
> > --
> > (when bandwidth gets better ;-)
> >
> > Chris Eastwood
> > Photographer, Programmer, Motorcyclist and dingbat
> >
> > please remove u n d i e s for reply
>
>
Received on Thu Jan 31 2002 - 08:33:01 CST