Changed Host CPU, now guests run really slowly and don't gram memory

[ohaya]

Hi,

I upgraded the CPU/processor on my PC tonight, from an AMD X2 to a Phenom quad-core.  Since then all of my guests have been running really sluggishly.  Everything is taking longer, from starting up the guests (a mix of Win2K servers, Win2K3 servers, an Centos 64-bit guests), and after they finally start, everything still is slow.

My host is running Windows 7 Ultimate 64 bit, and nothing else changed on the host... just the "faster" host processor.

I noticed that when I run Vmware Workstation and check memory usage in Task Manager, memory used is much, much less than before I changed to the new processor.  When I run my usual set of guests, they usually take about 25GB of memory (I have 32GB in this PC), and even just the main 6 guests usually take about 20GB of memory, but now, even with all of my guest running, Task Manager is showing only about10GB being used.

I checked the trimming configuration on each guest, and they all have the "disable trimming" checkbox checked.  I also checked under Edit=>Preferences=> Memory, and that's still set to run all guests in physical memory.

But, since changing the CPU/processor on the host, Workstation, between the sluggishness and not grabbing memory, Workstation sure seems to be behaving like trimming is enabled and like it's configured to swap out memory?

Can anyone tell me what might have happened, and also how do I fix this problem?

Thanks,

Jim

[ohaya]

Hi,

I forgot to mention that all of my guests (both Windows and Centos) are configured for 1 CPU only.

Would switching the host/physical CPU from a dual core CPU to the quad-core (Phenom) CPU cause guests to slow down?

As I said, how can I fix this? 

Thanks,

Jim

[kdshapiro]

You didn't say what version of VMWARE you are running. Did you check the Memory setting under the preferences? How much host memory do you have allocated and what is selection on the: "How should the system allocate memory for virtual machines?" question.

[admin]

Did you clear the NVRAM on the motherboard after changing the CPU?  Do you have the latest BIOS?  Is AMD-V enabled?

[ohaya]

kdshapiro,

The VMware Workstation version is the latest version of 6.5x.

The memory setting says something like 29+ GB. 

Originally, I had the setting you asked about set to allocate all memory, and also had the trim setting in all guests UNchecked. 

However, after that, for my testing purposes, I had to add an additional 4 guests, and started running into the 29+ GB maximum, so I changed that setting to allow some memory to be swapped, and have checked the "trim" setting on some of the guests to try to be able to run all of the guests, and they barely run now.

I think that I was mistaken on my original post, and that I just may have a lot (too much) of guests running.  I notice that after I start the guests, and as I start processes within the guests (now, 3 Oracle database instances, 6 WebLogic instances with applications, etc.) the memory usage shown in Windows 7 task manager slowly increases. 

I guess that I originally thought that with the memory setting set to having all guests run in physical memory and with all guests with trim UNchecked, that the guests should grab the amount of memory allocated to them immediately upon startup of the guests, but that doesn't seem like how Vmware workstation works?

Jim

[ohaya]

jmattson.

No, I didn't cleared NVRAM/CMOS after switching the CPU chips, and yes, I have the latest BIOS.  I will try that.

FYI, this is the original CPU:

http://www.newegg.com/Product/Product.aspx?Item=N82E16819103844

and here's the new one:

http://www.newegg.com/Product/Product.aspx?Item=N82E16819103727

I guess that I was just surprised that going to a faster host CPU, with 4 vs. 2 cores, hasn't really improved performance.  As I mentioned in my previous post, may be too many guests and memory usages, so ultimately the problem may be disk I/O.  I've been moving my guests around to try to get them on different hard drives and spindles (I have 4 hard drives in this machine), but ultmately, I may have to move some of them physically off of this one host onto another one, but I hate to do that.

Jim

[admin]

ohaya wrote:

FYI, this is the original CPU:

http://www.newegg.com/Product/Product.aspx?Item=N82E16819103844

and here's the new one:

http://www.newegg.com/Product/Product.aspx?Item=N82E16819103727

The old CPU did have twice the L2 cache per core that the new one has.  That could be responsible for some of the slowdown, but not likely anything visible to the naked eye.

Can you post a vmware.log file for one of the sluggish VMs?

[ohaya]

Hi,

Darn!  I missed that about the CPU cache size ...  I just *assumed* that the faster 4-core would have same or larger ...

I will try to figure out which vmware.log would be best, but at this point, I'm fighting how to get all of my guests to run since I added the additional ones.

Sorry, and thanks,

Jim

[admin]

The new CPU does have a large L3 cache, which the old one didn't have.  It's hard to say which is the better trade-off.  But if you're seeing visible sluggishness, I don't think the cache differences will explain it.