BL465c - OS crash after upgrade to 16GB RAM

[Pavel Simsalek]

Hello,
I have upgraded BL465c from 8 to 16 GB RAM. All memory modules are the same and working in other blades. During the boot of W2K3 ENT 32bit some processes did not start and after log-in screen server freezes. Bios Diagnostic utility - RAM passed. Any ideas?
Many thanks

[Gary Benavides Meza]

What kind of Windows 2003 Enterprise do you have?. The following list shows the memory limits on windows server 2003 Enterprise, assuming you have the Physical Address Extension (PAE) Enabled. Just in case check document attached to know how to enable PAE on windows and get more info:

Windows Server 2003, Enterprise Edition SP2 = 64 GB

Windows Storage Server 2003, Enterprise Edition = 8 GB

Windows Server 2003, Enterprise Edition R2 = 64 GB

Windows Server 2003, Enterprise Edition SP1 = 16 GB

Windows Server 2003, Enterprise Edition = 32 GB

[Timur S Lukovkin]

Are all the memories HP branded? have you tried to isolate the issue working with 2 memories and then swapping sticks in order to find the defective one? Could be a slot issue...

[Ron Burke]

Is it a G1 or G5? The attached BIOS setting automatically enables PAE. G5s come with it disabled by default.

When we first received our G5s, we had to remove dimms a pair at a time, and found the server would not boot due to bad memory not detected. We ran the HP smart start, and maintenance mode to force memory checks. There was no indication of bad memory until pulling dimms. Nothing in the logs or anywhere.

[Gary Benavides Meza]

???Is it a G1 or G5? The attached BIOS setting automatically enables PAE. G5s come with it disabled by default???

PAE is something that you enable on the Operating System not on the BIOS. It doesn't matter what the BIOS version is, if they have a 32bit operating System they need to enable PAE. PAE is enabled by default on some Linux Operating Systems depending on the kernel version. 64bit Operating Systems don't have this problem.

[Ron Burke]

Check out this quoute from Microsoft:

"To use these processor features, the processor must be running in Physical Address Extension (PAE) mode. However, Windows will automatically enable PAE mode to support DEP. Users do not have to separately enable PAE by using the /PAE boot switch."

From: http://support.microsoft.com/kb/875352

Check out the BIOS setting, I spent a day with HP Onsite Engineers verifying it. I wasn't aware of it either.

[Pavel Simsalek]

Thank you all for replies.
The server is BL465c G5, Windows is 2003 Enterprise Edition SP2.
PAE is enabled in boot.ini.
We have tried to swap modules, but everytime with 8GB is running and with 16 not.
Memory modules came directly from HP and are produced by SAMSUNG.

[Ron Burke]

Try removing the original 8GB of memory, and replaced those with the next 8GB.

Does the server see 16GB when it boots up before it gets to the operating system? Try going into Maintenance mode and force a memory test. It is F10 when the server starts to boot up.

You'll see
F9 For Setup
F10 For Maintenance
F12 PXE boot

Go to Diagnostic Utility
Do a memory test

Timur is right, sometimes you have to check the memory by removing the dims. This maintenance test may not be accurate. It happened to me also, on G5 servers.

[Pavel Simsalek]

I have tested the memory in diagnostic tools. Everything ok. Also different combinations of modules. All ok. Also BIOS knows that there is 16 GB.

Then i have reinstalled W2K3 and everything works now. Strange.

On other blade after upgrade to 16 GB, the same issue - solved: I booted into safe mode, removed /pae from boot.ini. Then booted normally (everything worked but with only 3,25 GB visible). Then enabled /pae again and after restart windows was working.
Thank you all for info and help.