I am working in an Oracle environment on an 8 GB system running Redhat 4.0 U3 (32-bit) with the U4 kernel. I am using 1.4 GB of hugepages and I have a ramdisk /dev/shm that is 1.2 GB in size for Oracle indirect data buffers.

When I run free, it tells me that I am using 2053960 of RAM and I have 6265372 available.

total used free shared buffers cached
Mem: 8308332 8273268 35064 0 124632 6094676
-/+ buffers/cache: 2053960 6254372
Swap: 5245096 50304 5194792

I can see from ipcs -m that I am using 1.4 GB of shared memory (in hugepages).

------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0xae126214 196609 oracle 600 1461714944 25
0x00000000 229378 oracle 640 4096 0
0xb1faa338 98307 oracle 640 241172480 15

So, I have two questions.
1. Is there a bug in free? Why is shared showing up as 0 when ipcs clearly shows that I am using 1.4 GB of shared memory?
2. How do I really know how much memory I am using?

Any help is appreciated. Thanks.
Ed

what's the output of 'cat /proc/meminfo'? Also, did you compile a custom kernel, or use a pre-built one? If prebuilt, do you know how the hi-mem is configured in it?

regards,
...drkstr

I won't have access to the system until Wednesday, but I am using the Redhat hugemem kernel prebuilt. No specific parameters except to mount the ramdisk and I have set hugpages=744. The interesting thing is that I have seen examples of the "free" command all over the internet, but I have never seen an example where shared is not 0.

/poc/meminfo contains some good info about your memory, it will probably give you what you need.

regards,
...drkstr

you could also user $ free -m

thx