Date: Wed, 23 Jul 2025 23:21:35 +0200 From: Rainer Duffner <rainer@ultra-secure.de> To: xyzzy@sysabend.org Cc: freebsd-virtualization@freebsd.org Subject: Re: Running FreeBSD 14.3 under XCP-NG performance issues Message-ID: <8533E4AC-3B62-47EC-91D1-4EFB8767B241@ultra-secure.de> In-Reply-To: <20250722210611.GC27456@moo.sysabend.org> References: <20250722210611.GC27456@moo.sysabend.org>
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> Am 22.07.2025 um 23:06 schrieb Tom Arnold <xyzzy@sysabend.org>: >=20 > I've been trying to get FreeBSD happy under our new XCP-NG setup. >=20 > The biggest problem I'm seeing right now is disk performance. >=20 > I built the VM on a 200gig LUN mapped from a Dell MD5. This disk = happened to > show up as /dev/ada0 and was installed with ZFS on Root. >=20 > After rebooting I added some more LUNs and put ZFS on them. These = disks happen to > show up with /dev/xbd# as Xen seems to be being detected after the = reboot. >=20 > Doing a simple performance test with dd ( if=3D/dev/zero of=3Dfile = bs=3D1m ) on anything > with a /dev/ada# entry I get a transfer rate of something around 6777 = MB/s. >=20 > Doing the same test on a device that is /dev/xbd# I get around half = that. >=20 > If I fight a bit and disable xenguest and get one of the "newer" LUNs = over to a > /dev/ada# device the performance goes up into the 6777 MB/s range. >=20 > I figure I'm doing something wrong here but docs seem to be sparse on = this and > Vates doesn't fully support FreeBSD so its a YMMV sorta thing. >=20 > Any suggestions? >=20 XCP-NG is Xen, right? Many, many years ago, I had similar problems with XenServer and FreeBSD. I opened a PR or two but nothing ever came out of it (you can find them We switched to KVM with Openstack and the problem was more or less the = same - until about FreeBSD 14.2, when I seemed to see a remarkable = performance-increase - though I haven=E2=80=99t benchmarked it.
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