[Resolved] Memory allocation failure after RAM upgrade in

[samsparks]

Howdy All,

First time poster - apologies if I miss some important information.

I've just upgraded my host OS from 4 to 6 GB RAM. After the change, all of my virtual box guest(s) crashes on memory intensive operations (ie - building an application from source). I've tried with a 32-bit and a 64-bit version of the guest.

Host Machine:
* Windows 7, SP1
* VirtualBox 4.3.12.r93733
Guest OS:
* OpenSUSE 11.2, Guest Additions installed
* Base Memory: 1024
* Acceleration: VT-x/AMD-V, Nested Paging

Log attached. I'm not including the screenshot, as it simply shows an open terminal running scons (in the gnome de)

Thanks in advance for the help!

[mpack]

You did a full power down and startup of the host, right? I.e. no hibernation.

As an aside: your host has a dual core CPU, so it doesn't make sense to assign 2 cores to the guest. Threads != Cores.

[samsparks]

Yup - I powered down the pc prior to installing the RAM, and even ran a memory check when I first noticed the failure.

I've assigned 2 cores to the guest so I can build using both cores. IIRC - this drastically reduces my build times during development

[loukingjr]

You've probably done this already but have you done any kind of extensive memory testing on the host alone to make sure the new memory is okay? Or for that matter have you removed the new memory to see if your guests run correctly again?

[samsparks]

Yes, I've done both.

The windows memory test (mdsched.exe) indicated no failures.
I've removed the memory, and everything is working as expected.

[loukingjr]

I vaguely remember reading years ago that if you are going to upgrade memory it should be in powers of 2, i.e.;2,4,8,16,32,64 etc. I could be remembering that incorrectly or the articles could have been nonsense. I have to say I don't remember seeing posts about VirtualBox and memory allocation errors.

One thing you could try I suppose is just use one old simm and one new simm and try and compile something in your guest that caused the crash. I'm at a loss really.

[mpack]

I vaguely remember reading years ago that if you are going to upgrade memory it should be in powers of 2, i.e.;2,4,8,16,32,64 etc.

I believe memory modules only ever come in powers of 2. I think what the rule actually was, was that all memory slots had to contain the same size memory. So, if you had two slots you musn't swap one slot for a large RAM module, you had to change both slots. Or you might have four slots, acting as 2+2 with each pair able to use different sizes.

I may have the details wrong, but I think that was the gist. But it's been a while since I added RAM to a PC, so I don't know what the current rules are.

[samsparks]

So, if you had two slots you musn't swap one slot for a large RAM module, you had to change both slots. Or you might have four slots, acting as 2+2 with each pair able to use different sizes.

Ah, this could be it. I only received one of the two modules I wanted to upgrade, so the sizes are temporarily different. I expect to receive the other one in about a week. I'll let you all know if this resolves it.

thanks for the help,
Sam

[samsparks]

Keeping the modules the same resolved my issue.

[mpack]

Thanks for reporting back.

[loukingjr]

I guess in my round about way that's what I was saying about the powers of 2. A 1GB and a 2GB simm equals 3GB < not a power of 2. A 2GB and a 4GB simm equals 6GB < not a power of two, etc.