Red Hat Summit Red Hat SummitSupportConsoleDevelopersStart a trialContact

10.4.6. Is Your RAM Not Being Recognized?

Sometimes, the kernel does not recognize all of your memory (RAM). You can check this with the cat /proc/meminfo command.
Verify that the displayed quantity is the same as the known amount of RAM in your system. If they are not equal, add the following line to the /boot/grub/grub.conf: 
mem=xxM
Copy to Clipboard Toggle word wrap
Replace xx with the amount of RAM you have in megabytes.
In /boot/grub/grub.conf, the above example would look similar to the following: 
# NOTICE: You have a /boot partition. This means that 
#  all kernel paths are relative to /boot/ 
default=0 
timeout=30 
splashimage=(hd0,0)/grub/splash.xpm.gz 
 title Red Hat Enterprise Linux Client (2.6.32.130.el6.i686)
root (hd0,1)
kernel /vmlinuz-(2.6.32.130.el6.i686 ro root=UUID=04a07c13-e6bf-6d5a-b207-002689545705 mem=1024M
initrd /initrd-(2.6.32.130.el6.i686.img
Copy to Clipboard Toggle word wrap
Once you reboot, the changes made to grub.conf are reflected on your system.
Once you have loaded the GRUB boot screen, type e for edit. You are presented with a list of items in the configuration file for the boot label you have selected.
Choose the line that starts with kernel and type e to edit this boot entry.
At the end of the kernel line, add 
mem=xxM
Copy to Clipboard Toggle word wrap
where xx equals the amount of RAM in your system.
Press Enter to exit edit mode.
Once the boot loader screen has returned, type b to boot the system.
Remember to replace xx with the amount of RAM in your system. Press Enter to boot.
Back to top
Red Hat logoGithubredditYoutubeTwitter

Learn

Try, buy, & sell

Communities

About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust. Explore our recent updates.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

Theme

© 2025 Red Hat