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shmmax limitation

Occasional Contributor

shmmax limitation

I have the OS version 11.31.
I only need to Know, the recommended value for the shmmax parameter is 0x40000000000.
Also some time, on application level trace I get the error message like
shmget() of 17179869184 bytes failed. errno = 12(Not enough space)
Can I set it with the 8 GB RAM and 20 GB SWAP?


Re: shmmax limitation

This hex value is way too big, two extra zeros?

Your colleague's thread?

While you can get 17 Gb, only if you have enough swap configured. What is "swapinfo -tam" when it fails?
Trusted Contributor

Re: shmmax limitation

For database servers, ideal shmmax value is equal to physical memory.

find out the physical memory.
#dmesg |grep -i phy
or glance

calculate shmmax in bytes.
phy mem * 1024 *1024

tune the parameter.
#kctune shmmax=value