> From: John Nielsen <li...@jnielsen.net> > Subject: Re: VMWare ESX and FBSD 7.2 AMD64 guest > To: freebsd-questions@freebsd.org > Cc: "Steve Bertrand" <st...@ibctech.ca> > Date: Friday, July 24, 2009, 10:22 AM > On Thursday 23 July 2009 19:44:15 > Steve Bertrand wrote: > > This message has a foot that has nearly touched down > over the OT > > borderline. > > > > We received an HP Proliant DL360G5 collocation box > yesterday that has > > two processors, and 8GB of memory. > > > > All the client wants to use this box for is a single > instance of Windows > > web hosting. Knowing the sites the client wants to > aggregate into IIS, I > > know that the box is far over-rated. > > > > Making a long story short, they have agreed to allow > us to put their > > Windows server inside of a virtual-ized container, so > we can use the > > unused horsepower for other vm's (test servers etc). > > > > My problem is performance. I'm only willing to make > this box virtual if > > I can keep the abstraction performance loss to <25% > (my ultimate goal > > would be 15%). > > > > The following is what I have, followed by my benchmark > findings: > > > > # 7.2-RELEASE AMD64 > > > > FreeBSD 7.2-RELEASE #0: Fri May 1 07:18:07 UTC > 2009 > > r...@driscoll.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC > > > > Timecounter "i8254" frequency 1193182 Hz quality 0 > > CPU: Intel(R) Xeon(R) CPU > 5150 @ 2.66GHz (2666.78-MHz > > K8-class CPU) > > Origin = "GenuineIntel" Id = > 0x6f6 Stepping = 6 > > > > usable memory = 8575160320 (8177 MB) > > avail memory = 8273620992 (7890 MB) > > > > FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs > > cpu0 (BSP): APIC ID: 0 > > cpu1 (AP): APIC ID: 1 > > cpu2 (AP): APIC ID: 6 > > cpu3 (AP): APIC ID: 7: > > Did you give the VM 4 virtual processors as well? How much > RAM did it have? > What type of storage does the server have? Did the VM just > get a .vmdk on > VMFS? What version of ESX? > > > Benchmarks: > > > > # time make -j4 buildworld (under vmware) > > > > 5503.038u 3049.500s 1:15:46.25 > 188.1% 5877+1961k 3298+586716io 2407pf+0w > > > > # time make -j4 buildworld (native) > > > > 4777.568u 992.422s 33:02.12 291.1% > 6533+2099k 25722+586485io 3487pf+0w > > Note that the "user" time is within your 15% margin (if you > round to the > nearest percent). The system time is what's running away. > My guess is that > that is largely due to disk I/O and virtualization of same. > What you can do > to address this depends on what hardware you have. Giving > the VM a raw > slice/LUN/disk instead of a .vmdk file may improve matters > somewhat. If you > do use a disk file be sure that it lives on a stripe (or > whatever unit is > relevant) boundary of the underlying storage. Ways to do > that (if any) depend > on the storage. Improving the RAID performance, etc. of the > storage will > improve your benchmark overall, and may or may not narrow > the divide. > > The (virtual) storage driver (mpt IIRC) might have some > parameters you could > tweak, but I don't know about that off the top of my head. > > > ...both builds were from the exact same sources, and > both runs were > > running with the exact same environment. I was > extremely careful to > > ensure that the environments were exactly the same. > > > > I'd appreciate any feedback on tweaks that I can make > (either to VMWare, > > or FreeBSD itself) to make the virtualized environment > much more efficient. > > See above about storage. Similar questions come up > periodically; searching the > archives if you haven't already may prove fruitful. You may > want to try > running with different kernel HZ settings for instance. > > I would also try to isolate the performance of different > components and > evaluate their importance for your actual intended load. > CPU and RAM probably > perform like you expect out of the box. Disk and network > I/O won't be as > close to native speed, but the difference and the impact > are variable > depending on your hardware and load. > > A lightly-loaded Windows server is the poster child of > virtualization > candidates. If your decision is to dedicate the box to > Winders or to > virtualize and use the excess capacity for something else I > would say it's a > no-brainer if the cost of ESX isn't a factor (or if ESXi > gives you similar > performance). If that's already a given and your decision > is between running > a specific FreeBSD instance on the ESX host or on its own > hardware then > you're wise to spec out the performance differences. > > HTH, > > JN
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!). -Rich *Since I'm recalling it, the standard caveats about my bad memory apply. In this case, there's also the caveats about the VI instructor's bad memory, too. :) _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
