Skip to Main Content

Oracle Database Discussions

Announcement

For appeals, questions and feedback about Oracle Forums, please email oracle-forums-moderators_us@oracle.com. Technical questions should be asked in the appropriate category. Thank you!

How to reduce the blocksize of redo log files

Bernd W.Oct 18 2017 — edited Oct 18 2017

Hello,

We are running an Oracle Enterprise Database (11.2.0.4.170718) and use redo log files with 4k blocksize. Now we want to change the hardware and use a storage system with 512 bytes logical sector size. Therefore we shut down the database, backup all files and restore the files on the new hardware.

While trying to startup the database we got errors like

Errors in file ..\tr41e3v_j000_5556.trc:

ORA-00313: Member von Log-Gruppe 2 (Thread 1) konnten nicht geöffnet werden

ORA-00312: Online-Log 2, Thread 1: 'F:\ORADATA\TR41E3V\DB_REDO\REDO02.LOG'

ORA-01382: Thread 1 konnte Log-Datei ..\REDO02.LOG nicht öffnen. Die Blockgröße der Log-Datei (4096) ist größer als die Datenträgersektorgröße (512).

What may be the best way to reduce the blocksize from 4k to 512 byte?

One possible way to start the database may be:

a) Mount the Databasse

b) Add new redo log files with 512 byte blocksize

c) ALTER SYSTEM SET "_DISK_SECTOR_SIZE_OVERRIDE"=TRUE;

d) Open Database and switch to the new log files (ALTER SYSTEM SWITCH LOGFILE, ALTER SYSTEM CHECKPOINT)

e) ALTER SYSTEM SET "_DISK_SECTOR_SIZE_OVERRIDE"=FALSE;

f) Restart the database

  I have read that using the parameter "_DISK_SECTOR_SIZE_OVERRIDE" requires permission from Oracle Support. Is that true?

Comments
Locked Post
New comments cannot be posted to this locked post.
Post Details
Locked on Nov 15 2017
Added on Oct 18 2017
9 comments
2,273 views