In our RHEL5 monitoring station with 10 monitors, we’ve been having some problems with crashes. Turns out that the kernel we were using, which was the standard kernel, would not access all of the ram in our system. (Currently 4GB) By installing and running the PAE (Physical Address Extension) kernel, we are now able to get all the ram in our system.
Old kernel and ram:
[~]# more mem1.txt
Linux monstation 2.6.18-164.2.1.el5 #1 SMP Mon Sep 21 04:37:51 EDT 2009 i686 i686 i386 GNU/Linux
total used free shared buffers cached
Mem: 2265 938 1327 0 191 605
-/+ buffers/cache: 141 2124
Swap: 1027 0 1027
Total: 3293 938 2355
New kernel and ram:
[~]# more mem-PAE.txt
Linux monstation 2.6.18-164.2.1.el5PAE #1 SMP Mon Sep 21 04:45:05 EDT 2009 i686 i686 i386 GNU/Linux
total used free shared buffers cached
Mem: 4043 837 3205 0 65 569
-/+ buffers/cache: 202 3841
Swap: 1027 0 1027
Total: 5071 837 4233
I’ve ordered four more gb of ram for this system, so we’ll have it maxed out at 8gb.