Date: Fri, 17 Jan 2014 10:17:11 +0100 From: Sydney Meyer <meyer.sydney@googlemail.com> To: freebsd-virtualization@freebsd.org Subject: Re: Xen PVHVM with FreeBSD10 Guest Message-ID: <A5ECBAEA-8E55-4D95-87D0-5FFC1D559BA3@googlemail.com> In-Reply-To: <52D8F301.2080701@citrix.com> References: <9DF57091-9957-452D-8A15-C2267F66ABEC@googlemail.com> <52D81009.6050603@citrix.com> <51F93577-E5A2-4237-9EDD-A89DDA5FC428@gmail.com> <F672F9F6-7F85-4315-AFA0-EA18527A1893@googlemail.com> <52D8F301.2080701@citrix.com>
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I=92m doing some benchmarks with bonnie and dd on the Variations = 9.2/10.0;PVHVM/VirtIO;fileio/blockio. I will post the results here to = this thread. On 17.01.2014, at 10:08, Roger Pau Monn=E9 <roger.pau@citrix.com> wrote: > On 16/01/14 19:38, Sydney Meyer wrote: >> Well then, thanks for the hint.. dmesg shows the following: >>=20 >> Jan 16 18:22:30 bsd10 kernel: xn0: <Virtual Network Interface> at = device/vif/0 on xenbusb_front0 >> Jan 16 18:22:30 bsd10 kernel: xn0: Ethernet address: = 00:16:3e:df:1b:5a >> Jan 16 18:22:30 bsd10 kernel: xenbusb_back0: <Xen Backend Devices> on = xenstore0 >> Jan 16 18:22:30 bsd10 kernel: xn0: backend features: feature-sg = feature-gso-tcp4 >> Jan 16 18:22:30 bsd10 kernel: xbd0: 8192MB <Virtual Block Device> at = device/vbd/768 on xenbusb_front0 >> Jan 16 18:22:30 bsd10 kernel: xbd0: attaching as ada0 >> Jan 16 18:22:30 bsd10 kernel: xbd0: features: flush, write_barrier >> Jan 16 18:22:30 bsd10 kernel: xbd0: synchronize cache commands = enabled. >>=20 >> Now i did some tests with raw images and the disk performs very well = (10-15% less than native throughput). >=20 > So the problem only manifest itself when using block devices as disk > backends? >=20 > I've done some tests with fio using direct=3D1 (and a LVM volume as = the > backend), and it shows that disk writes are slower when using PV = drivers > instead of the emulated ones. On the other hand disk reads are faster > when using the PV drivers. Have you tried if the 9.x series also show > the same behaviour? (you will have to compile the custom XENHVM = kernel) >=20 > Roger. >=20
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