Redo Log Block Size on IBM: Linux on System z (Doc ID 1605309.1)

Last updated on APRIL 24, 2017

Applies to:

Oracle Database - Enterprise Edition - Version 11.2.0.3 and later
IBM: Linux on System z

Goal

To create redo logs with a block size of 512 on block devices with a 512byte sector size on the IBM: Linux on System z platform to avoid wasting redo log space.

 

A block device "/dev/sda1" which has an ext3 filesystem with a default blocksize of 4K have redo log files with a default block size of 4k despite having a sector size of 512bytes.

The sector size is 512:-

# blockdev --getpbsz /dev/sda1
512

When adding redo logs they are created with a default block size of 4K:-

SQL>select blocksize from v$log


BLOCKSIZE
----------
     4096

 

When attempting to override the default blocksize e.g. as per http://docs.oracle.com/cd/E18283_01/server.112/e17120/onlineredo002.htm#CHDFBDJC

SQL>  alter database add logfile group 10 '/oracle/redo/redo10-tmp.log' size 10m blocksize 512 reuse;
alter database add logfile group 10 '/oracle//redo/redo10-tmp.log' size 10m blocksize 512 reuse
                                                                                                  *
ERROR at line 1:
ORA-01377: Invalid log file block size

 

Solution

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