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@xxxxxxxxxx] >Sent: Friday, June 25, 2004 11:17 AM >To: oracle-l@xxxxxxxxxxxxx >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 >---------------------------------------------------------------- >Please see the official ORACLE-L FAQ: http://www.orafaq.com >---------------------------------------------------------------- >To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx >put 'unsubscribe' in the subject line. >-- >Archives are at //www.freelists.org/archives/oracle-l/ >FAQ is at //www.freelists.org/help/fom-serve/cache/1.html >----------------------------------------------------------------- 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 ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------