Can Oracle on Windows replicate to Linux for a near-zero down-time server move?

Jon Cowling 07-Mar-2016 10:11:11

Can Oracle on Windows replicate to Linux for a near-zero down-time server move?

The answer; Yeah, probably…..

I have often thought that there is no good reason why Linux and Windows could not share a database of the same version because after-all they are the same endian type.

And so, when a DSP customer posed the question to the DBA team, i decided it was time to prove (or disprove) the possibility.

I took a Windows 7 Ultimate! edition 64-bit VM, and loaded SE with grid infrastructure for stand-alone server and a single ASM disk (+DATA), and then knocked up an Oracle Enterprise Linux 6.7 VM, and loaded it with GI & RDBMS and got to work!

I used RMAN to backup the MS Win database to a normal NTFS filesystem, got a backup of the SPFILE, created a standby control file, and then loaded the lot onto my NAS before SCP’ing the files across to the waiting OEL 7.

I edited the PFILE for path changes (F:\app\ turned into /u01/app), recreated the password file, and inserted a line into /etc/oratab.

Exported my ORACLE_HOME, ORACLE_SID and PATH variables in my .bash_profile, jumped into SQLPlus, and startup nomount pfile=‘/u01/app/backup/test.pfile’

Create spfile from pfile=‘/u01/app/backup/test.pfile’;

Restarted with no mount, and then switched to RMAN for the moment of truth.

Once in RMAN, I restored the controlfile from ‘/u01/backup/test.ctl’;

alter database mount;

catalog start with ‘/u01/backup/‘ noprompt;

and then performed a crosscheck to get rid of those pesky windows paths out of the control file.

After that, it was a simple matter of restoring and recovering the database, I switched logs a few times on the source (shipped them using the same method - I couldn’t be bothered installing Cygwin).

I only restored one of the logs to the FRA on the new host, and rolled that single new log into the database (SQLPlus> recover standby database) and ….. POINT PROVEN!!!!!!!

After ‘alter database activate standby database;’ and ‘alter database open;’, it was time to start gloating :)