SQL*Plus: Release 10.2.0.4.0 - Production on Mon Jun 9 14:32:37 2008

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SQL> conn /as sysdba
Connected to an idle instance.
SQL> STARTUP
ORA-27126: unable to lock shared memory segment in core
IBM AIX RISC System/6000 Error: 1: Not owner

Changes

The Oracle Home binaries have been patched to 10.2.0.4.0.

Cause

"oracle" user does not have the required OS capabilities. When LOCK_SGA is set to TRUE in 10.2.0.4, "oracle" user must have OS large pages capabilities.

Following command can be used to check "oracle" user capabilities
$ lsuser -a capabilities oracle

Solution

1. Add the CAP_BYPASS_RAC_VMM and CAP_PROPAGATE capabilities to "oracle" user
# chuser capabilities=CAP_BYPASS_RAC_VMM,CAP_PROPAGATE oracle

2. Configure the AIX large page pool by calculating the number of large pages required for the SGA:
num_of_large_pages = INT((total_SGA_size-1)/16MB)+1

3. Configure the number and size of large pages:
# vmo -p -o lgpg_regions=num_of_large_pages -o lgpg_size=16777216

这里根据我设置SGA为4000M，进行

# vmo -p -o lgpg_regions=300 -o lgpg_size=16777216

调整后数据库可以正常启动

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