Why does the kernel parameter SHMMAX appear to be 0 even after seting it to a higher value on Red Hat Enterprise Linux 32-bit?

Solution Verified - Updated -


  • After setting kernel parameter SHMMAX to a value larger than 4GB on a 32-bit Red Hat Enterprise Linux system, this value appears to be reset to 0.

For example, to check the value of SHMMAX:

# cat /proc/sys/kernel/shmmax
  • This is the default value of SHMMAX.

Then set a new value to SHMMAX, one byte higher:

# echo 4294967296 > /proc/sys/kernel/shmmax
  • Check the value and find that it is 0:
# cat /proc/sys/kernel/shmmax


  • Red Hat Enterprise Linux, all 32-bit versoins

Subscriber exclusive content

A Red Hat subscription provides unlimited access to our knowledgebase of over 48,000 articles and solutions.

Current Customers and Partners

Log in for full access

Log In

Welcome! Check out the Getting Started with Red Hat page for quick tours and guides for common tasks.