Date: Wed, 14 Sep 2016 15:04:18 +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-LF1GfSfCxL@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 #5 from rainer@ultra-secure.de --- 10.3-RELEASE-p5: (server </srv>) 0 # time dd if=3D/dev/zero of=3Dtest.dat bs=3D64k count=3D2= 0480 20480+0 records in 20480+0 records out 1342177280 bytes transferred in 1.769942 secs (758317078 bytes/sec) dd if=3D/dev/zero of=3Dtest.dat bs=3D64k count=3D20480 0.02s user 1.75s sy= stem 99% cpu 1.775 total (server </srv>) 0 # time dd if=3D/dev/zero of=3Dtest.dat bs=3D64k count=3D2= 04800 204800+0 records in 204800+0 records out 13421772800 bytes transferred in 17.266468 secs (777331701 bytes/sec) dd if=3D/dev/zero of=3Dtest.dat bs=3D64k count=3D204800 0.15s user 17.06s = system 99% cpu 17.271 total This is ZFS. Probably due to compression on. root@other-server:/srv# lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 14.04.4 LTS Release: 14.04 Codename: trusty root@other-server:/srv# time dd if=3D/dev/zero of=3Dtest.dat bs=3D64k count= =3D20480 20480+0 records in 20480+0 records out 1342177280 bytes (1.3 GB) copied, 2.5559 s, 525 MB/s real 0m2.571s user 0m0.041s sys 0m2.125s root@other-server:/srv# time dd if=3D/dev/zero of=3Dtest.dat bs=3D64k count= =3D204800 204800+0 records in 204800+0 records out 13421772800 bytes (13 GB) copied, 93.6892 s, 143 MB/s real 1m33.940s user 0m0.219s sys 0m26.136s root@yet-another-server:/srv# lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 16.04.1 LTS Release: 16.04 Codename: xenial root@yet-another-server:/srv# time dd if=3D/dev/zero of=3Dtest.dat bs=3D64k count=3D20480 20480+0 records in 20480+0 records out 1342177280 bytes (1.3 GB, 1.2 GiB) copied, 1.62124 s, 828 MB/s real 0m1.652s user 0m0.004s sys 0m1.616s root@yet-another-server:/srv# time dd if=3D/dev/zero of=3Dtest.dat bs=3D64k count=3D204800 204800+0 records in 204800+0 records out 13421772800 bytes (13 GB, 12 GiB) copied, 100.348 s, 134 MB/s real 1m40.711s user 0m0.172s sys 0m25.004s So, in this particular test, it's actually faster. But I can assure you, in practical use, it's not. 10.3-RELEASE-p7, UFS: (freebsd-srv2 </srv>) 0 # time dd if=3D/dev/zero of=3Dtest.dat bs=3D64k cou= nt=3D20480 20480+0 records in 20480+0 records out 1342177280 bytes transferred in 8.746548 secs (153452229 bytes/sec) dd if=3D/dev/zero of=3Dtest.dat bs=3D64k count=3D20480 0.02s user 1.65s sy= stem 19% cpu 8.756 total (freebsd-srv2 </srv>) 0 # time dd if=3D/dev/zero of=3Dtest.dat bs=3D64k cou= nt=3D204800 204800+0 records in 204800+0 records out 13421772800 bytes transferred in 99.078364 secs (135466233 bytes/sec) dd if=3D/dev/zero of=3Dtest.dat bs=3D64k count=3D204800 0.22s user 18.20s = system 18% cpu 1:39.30 total --=20 You are receiving this mail because: You are the assignee for the bug.=
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