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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Hot Backup Theory Revisited:
Because the control file, like Oracle DataFiles, is larger than 1 OS
FileSystem Block.
An OS copy can result in a fragmented copy of the ControlFile. AND since
you have multiple
controlfiles, do NOT attempt to copy all the copies -- OS reads will
certainly be inconsistent.
Oracle DataFiles are protected by the ArchiveLogs after you issue an ALTER
TABLESPACE BEGIN BACKUP
but there is no such protection. The only way to get a consistent copy of
the ControlFile
is to use the ALTER DATABASE BACKUP CONTROLFILE command which actually
"locks" the file {ie Oracle does not write to it while it is copying it
out} and also which is
copied out by Oracle itself .
Hemant
At 01:03 AM Saturday, you wrote:
>Why OS copy of control file won't work?
>
>Guang
>
> > -----Original Message-----
>Guang,
>Under normal circumstances yes, but the control file has to be a "alter
>database backup controlfile . . .", not a OS copy.
>
>Mike
>
>-----Original Message-----
>From: Guang Mei [mailto:gmei_at_incyte.com]
>Sent: Friday, June 25, 2004 11:17 AM
>To: oracle-l_at_freelists.org
>Subject: RE: Hot Backup Theory Revisited:
>
>
>I am trying to understand:
>
>Is it true that if the copy of control file (just an OS copy) is done AFTER
>issuing
>
>ALTER SYSTEM ARCHIVE LOG CURRENT;
>
>then no earlier (than the log switch) archive log is needed? We still need
>the archive logs generated during tablespace backup process.
>
>Guang
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Hemant K Chitale
Oracle 9i Database Administrator Certified Professional
http://web.singnet.com.sg/~hkchital
All the suffering in the world arises out of wanting happiness for self. All happiness in the world arises out of wanting happiness for others. - Shantideva
Hemant K Chitale
Oracle 9i Database Administrator Certified Professional
http://web.singnet.com.sg/~hkchital
-- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------Received on Sun Jun 27 2004 - 08:07:14 CDT
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