linux上Oracle的sga(HugePages)分配问题

Yong Huang

You do need to actually use buffer cache and shared pool to use HugePages. If you were on Red Hat 5, you would have a line for reserved HugePages:

HugePages_Total:  1030
HugePages_Free:    696
HugePages_Rsvd:    691
Hugepagesize:     2048 kB

The above is from a RHEL5 box about 10 minutes after the box is rebooted and instance started. As long as HugePages_Free is only slightly larger than HugePages_Rsvd, it's good. In RHEL4, you just keep using SGA and the HugePages_Free number will decrease.

Yong Huang

wzcfine

我的os也是 REHL 5.2的 32bit，在meminfo里怎么没有
HugePages_Total:  1030
HugePages_Free:    696
HugePages_Rsvd:    691
Hugepagesize:     2048 kB
此类信息呢内核是2.18的。limits.cong 设置的值为：
oracle soft memlock 3145728
oracle hard memlock 3145728

Yong Huang

wzcfine,

Can you show this?

cat /etc/redhat-release
uname -a #you can mask the hostname part
grep Huge /proc/meminfo

Yong Huang

bee002

我认为，sga的大部分被linux看做是free内存了。