Oracle警告日志WARNING : Parameter _linux_prepage_large_pages Is Explicitly Disabled

 

在集群上创建了6个实例后，启动实例警告日志有如下警告信息：

Starting ORACLE instance (normal)
************************ Large Pages Information *******************
Per process system memlock (soft) limit = UNLIMITED

Large page usage restricted to processor group "system.slice/ohasd.service"

Total Shared Global Region in Large Pages = 13 GB (100%)

WARNING:
  The parameter _linux_prepage_large_pages is explicitly disabled.
  Oracle strongly recommends setting the _linux_prepage_large_pages
  parameter since the instance  is running in a Processor Group. If there is
  insufficient large page memory, instance may encounter SIGBUS error
  and may terminate abnormally.

Large Pages used by this instance: 6561 (13 GB)
Large Pages unused in Processor Group system.slice/ohasd.service = 16439 (32 GB)
Large Pages configured in Processor Group system.slice/ohasd.service = 23000 (45 GB)
Large Page size = 2048 KB
********************************************************************

之前只有1个实例的时候并不会提示这类信息，包括以前经验配置那么多数据库也是没见过。

猜测这是因为集群注册多个实例以上才会发生，第二就是不是集群可能多个实例也不会提示。找个机会验证下。

 

当我6个实例全部打开后，查看大页使用情况发现并没有的大页内存被使用上。

[oracle@dev-testdb ~]$ grep -i hugepage /proc/meminfo 
AnonHugePages:         0 kB
ShmemHugePages:        0 kB
FileHugePages:         0 kB
HugePages_Total:   23000
HugePages_Free:    18392
HugePages_Rsvd:    18358
HugePages_Surp:        0
Hugepagesize:       2048 kB

当根据建议设置"_linux_prepage_large_pages"=TRUE后，重启全部实例，则为：

grep -i hugepage /proc/meminfo 
AnonHugePages:         0 kB
ShmemHugePages:        0 kB
FileHugePages:         0 kB
HugePages_Total:   23000
HugePages_Free:       34
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB

 

参考文档

WARNING : Parameter _linux_prepage_large_pages Is Explicitly Disabled (文档 ID 2414778.1)