VMWare ESX and FBSD 7.2 AMD64 guest

Steve Bertrand steve at ibctech.ca
Fri Jul 24 16:02:02 UTC 2009

Richard Mahlerwein wrote:

> If I recall correctly from ESX (well, VI) training*, there may be a minor scheduling issue affecting things here.  If you set up the VM with 4 processors, ESX schedules time on the CPU only when there's 4 things to execute (well, there's another time period it also uses, so even a single thread will get run eventually, but anyway...).  The physical instance will run one thread immediately even if there's nothing else waiting, whereas the VM will NOT execute a single thread necessarily immediately.  I would retry using perhaps -j8 or even -j12 to make sure the 4 CPUs see plenty of work to do and see if the numbers don't slide closer to one another.  
> For what it's worth, if there were a raw LUN available and made available to the VM, the disk performance of that LUN should very nearly match native performance, because it IS native performance.  VMWare (if I understood right in the first place and remember correctly as well, I supposed I should * this as well. :) ) doesn't add anything to slow that down.  Plugging in a USB drive to the Host and making it available to the guest would also be at native USB/drive speeds, assuming you can do that (I've never tried to use USB drives on our blade center!).

I've isolated the problem to the SATA RAID system (or subsystem).

Booting from CD/USB key and running a wide array of bench tests, I can
not read from the RAID setup faster than 10MBps.

Regardless of anything else, this is my priority.

RAID 0 is the only config where I can read faster than ~7MBps. The board
does not have any standard IDE interfaces, and I don't have any PCIe-IDE
cards that aren't in use, so I can't really bypass the HP RAID card.

I will however slap a 200GB USB drive against the box, and see if I can
get faster performance from USB than I can the native SATA setup.

FWIW, I do have the battery backed cache installed...

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