On Mon, Aug 9, 2010 at 12:38 PM, Ivan Voras <[email protected]> wrote:
> On 9 August 2010 18:11, Jeremy Chadwick <[email protected]> wrote: > > > I thought Intel VT-d was supposed to help address things like this? > > Probably - > http://www.intel.com/technology/itj/2006/v10i3/2-io/7-conclusion.htm > says it should help unmodified guests, but I don't know for sure. I do > know that Nehalems run faster on VMWare, probably because "nested > paging" or whatever it's called helps context switches on syscalls. > > > I can confirm on VMware Workstation 7.1, not ESXi, that disk I/O > > performance isn't that great. I only test with a Host OS of Windows XP > > SP3, and for the Guest OS's hard disk driver use the LSI SATA/SAS > > option. I can't imagine IDE/ATA being faster, since (at least > > Workstation) emulates an Intel ICH2. > > Yes, disk IO was always slow with VMWare. VirtualBox cheats by > emulating ATA controllers (ICH6) instead of SCSI and turning on disk > cache - it's noticably faster than VMWare. > I've only tried the SAS/SCSI controllers in ESXI. Perhaps I should try ATA... > > > I was under the impression that ESXi provided native access to the > > hardware in the system (vs. Workstation which emulates everything)? > > I think it can be configured this way, but then you'd need a separate > LUN for the VM drive, bypassing vmware's usual storage (vmfs) and all > the goodies that come with it. OTOH, there are paravirtualized drivers > for Linux and Windows in 4.0 which should help, but I haven't tried > them yet. > It can be configured this way, but then you'd have to pre-allocate LUNs for each of your VMs ... not all that convenient. > > > The controller seen by FreeBSD in the OP's system is: > > > > mpt0: <LSILogic SAS/SATA Adapter> port 0x4000-0x40ff mem > 0xd9c04000-0xd9c07fff,0xd9c10000-0xd9c1ffff irq 18 at device 0.0 on pci3 > > mpt0: [ITHREAD] > > mpt0: MPI Version=1.5.0.0 > > > > Which looks an awful lot like what I see on Workstation 7.1. > > > > FWIW, Workstation 7.1 is fairly adamant about stating "if you want > > faster disk I/O, pre-allocate the disk space rather than let disk use > > grow dynamically". I've never tested this however. > > Yes, this statement has always been true. > > > How does Linux's I/O perform with the same setup? > > I've tested Linux, Windows and FreeBSD on VMWare 3.5 last year and the > results (IOPS) were: > > ESXi-FreeBSD 174 > ESXi-Linux 221 > ESXI-Windows 98 > Xen-FreeBSD 72 > Xen-Linux 148 > Xen-Linux-PV 244 > HyperV-FreeBSD 61 > HyperV-Linux 69 > HyperV-Windows 58 > > (I couldn't get Windows to run on Xen; "Linux-PV" is Linux as > paravirtualized Xen guest). > -- Joshua Boyd JBipNet E-mail: [email protected] http://www.jbip.net _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[email protected]"
