Date: Fri, 10 Feb 2017 16:42:00 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-xen@FreeBSD.org Subject: [Bug 212681] I/O is slow for FreeBSD DOMu on XenServer Message-ID: <bug-212681-23905-Mplo2PMfC2@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-212681-23905@https.bugs.freebsd.org/bugzilla/> References: <bug-212681-23905@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D212681 --- Comment #37 from Roger Pau Monn=C3=83=C2=A9 <royger@freebsd.org> --- (In reply to Roger Pau Monn=C3=83=C2=A9 from comment #33) So I've run the dc3dd test on a FreeBSD VM, with 4 vCPUs and 4GB of RAM, against a block device on a spinning disk, nothing fancy, and this is what I get: (FreeBSD guest) # dc3dd wipe=3D/dev/ada1 dc3dd 7.2.641 started at 2017-02-10 16:19:54 +0000 compiled options: command line: dc3dd wipe=3D/dev/ada1 device size: 20971520 sectors (probed), 10,737,418,240 bytes sector size: 512 bytes (probed) 10737418240 bytes ( 10 G ) copied ( 100% ), 125 s, 82 M/s input results for pattern `00': 20971520 sectors in output results for device `/dev/ada1': 20971520 sectors out dc3dd completed at 2017-02-10 16:21:58 +0000 Then I shut down the guest, and ran the same test from Dom0 (Debian Linux 3= .16) against the same exact block device, and this is what I get: (Linux Dom0) # dc3dd wipe=3D/dev/dt51-vg/test dc3dd 7.2.641 started at 2017-02-10 16:31:34 +0000 compiled options: command line: dc3dd wipe=3D/dev/dt51-vg/test device size: 20971520 sectors (probed), 10,737,418,240 bytes sector size: 512 bytes (probed) 10737418240 bytes ( 10 G ) copied ( 100% ), 114 s, 90 M/s input results for pattern `00': 20971520 sectors in output results for device `/dev/dt51-vg/test': 20971520 sectors out dc3dd completed at 2017-02-10 16:33:28 +0000 So there's a < 10M/s difference, which I think it's fine (at the end there's always some overhead). I cannot really explain the results that you get, but I cannot also reprodu= ce your entire setup here. This is using the 12.0-CURRENT snapshot from 201702= 03. I'm afraid that unless we find a way for me to reproduce this, there's no w= ay that I can try to fix it. --=20 You are receiving this mail because: You are the assignee for the bug.=
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