【翻译自mos文章】11.2.0.4及更高版本号的asm实例中MEMORY_TARGET 和 MEMORY_MAX_TARGET的默认值和最小值
来源于：
Default and Minimum MEMORY_TARGET & MEMORY_MAX_TARGET Value for ASM 11.2.0.4 and Onwards (文档 ID 1982132.1)

APPLIES TO:

SYMPTOMS

1) ASM MEMORY_TARGET & MEMORY_MAX_TARGET cannot be set less than 1GB on 11.2.0.4 release and onwards.

2) If ASM MEMORY_TARGET  & MEMORY_MAX_TARGET is set to a lower value < 1GB, then MEMORY_TARGET & MEMORY_MAX_TARGET are automatically reset back to its default value MEMORY_TARGET= 1GB:

$>  sqlplus / as sysdbaSQL*Plus: Release 11.2.0.4.0 Production on Sun Feb 8 19:17:32 2015Copyright (c) 1982, 2013, Oracle. All rights reserved.Connected to:Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit ProductionWith the Real Application Clusters and Automatic Storage Management optionsSQL> show parameter memory_targetNAME TYPE VALUE------------------------------------ ----------- ------------------------------memory_target big integer 1GSQL> show parameter memory_max_targetNAME TYPE VALUE------------------------------------ ----------- ------------------------------memory_max_target big integer 1G 

3) Also, ASM will report in the ASM alert.log the following banner (during the ASM instance startup):

MEMORY_TARGET defaulting to 1128267776.

CAUSE

1) The following enhancement requests stated that the default & minimum value for MEMORY_MAX_TARGET & MEMORY_TARGET is now 1GB starting on 11.2.0.4 release andonwards:

<-o-> Bug 13563723 - INCREASE THE DEFAULT MEMORY_TARGET FOR ASM<-o-> Bug 17460037 - MEMORY_TARGET DEFAULTING TO 1128267776

2) And if you attempt to set a value lower, that value is automatically reset back to 1GB.

SOLUTION

Starting on 11.2.0.4 release and onwards ASM MEMORY_MAX_TARGET & MEMORY_TARGET need to be set = 1GB or higher.