Date: Fri, 17 Aug 2007 15:52:41 -0700 (PDT) From: "N. Harrington" <drumslayer2@yahoo.com> To: Pawel Jakub Dawidek <pjd@FreeBSD.org> Cc: freebsd-fs@freebsd.org Subject: Re: Gjournal reporting 1/2 the speed of non journaled? - examples Message-ID: <718389.22856.qm@web34515.mail.mud.yahoo.com> In-Reply-To: <20070817154139.GA1089@garage.freebsd.pl>
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--- Pawel Jakub Dawidek <pjd@FreeBSD.org> wrote: > On Thu, Aug 16, 2007 at 06:02:09PM -0700, N. > Harrington wrote: > > With ZFS, I have not seen much new going on with > > gjournal. I am curious what the status of gjournal > and > > if it will likely be included with 6.3 (whenever > that > > is due) > > That was the plan, but I'm not yet sure if I'll find > time to do it. > > > Also, as of late, I have been using it with > > 6.2-STABLE via the patches and I seem to be > getting > > 1/2 the transfer speeds compared to non journaled > > disks. It seems like this is recent as previous > tests > > showed it as quite fast. > > > > Any suggestions on why this could be happening > > greatly appreciated. > > > > tested via > > dd if=/dev/zero of=./testfile bs=16 count=16384 > > Gjournal is ~two times faster than UFS+SU for many > small, random and > parallel writes (such as running few 'tar x' > processes), but is two > times slower than UFS+SU for one sequential write > stream, as there is no > much that can be optimized there. > > > With disks getting larger and larger, why is it > > taking so long for a journaled filesystem to be > > standard on BSD? > > We have ZFS now, we don't need journaled file > system:) Here is an example of my tests and what I am experiencing. FreeBSD server.old 6.2-PRERELEASE FreeBSD 6.2-PRERELEASE #1: Wed Nov 22 21:20:08 PST 2006 With Gjournal: root@:/1-journal> time dd if=/dev/zero of=/1-journal/testfile1 bs=16k count=16384 16384+0 records in 16384+0 records out 268435456 bytes transferred in 10.257279 secs (26170240 bytes/sec) dd if=/dev/zero of=/cache1/testfile1 bs=16k count=16384 0.02s user 0.80s system 7% cpu 10.393 total Without Gjournal: root@1:/2-UFS> time dd if=/dev/zero of=/2/testfile1 bs=16k count=16384 16384+0 records in 16384+0 records out 268435456 bytes transferred in 26.682630 secs (10060307 bytes/sec) dd if=/dev/zero of=/home/testfile1 bs=16k count=16384 0.01s user 0.61s system 2% cpu 28.448 total As you can see, with this test, using Gjournaling tested faster. Now on a new build: FreeBSD newtest 6.2-STABLE FreeBSD 6.2-STABLE #1: Tue Aug 14 14:31:53 PDT 2007 nicole@newtest:/usr/obj/spare/src/sys/GENERAL amd64 Without Gjournal root@newtest:/home/nicole> time dd if=/dev/zero of=./testfile bs=16k count=16384 16384+0 records in 16384+0 records out 268435456 bytes transferred in 4.749401 secs (56519854 bytes/sec) dd if=/dev/zero of=./testfile bs=16k count=16384 0.01s user 0.45s system 9% cpu 4.751 total With Gjournaling: root@newtest:/home/nicole> time dd if=/dev/zero of=/tmp/testfile bs=16k count=16384 16384+0 records in 16384+0 records out 268435456 bytes transferred in 7.505348 secs (35765891 bytes/sec) dd if=/dev/zero of=/tmp/testfile bs=16k count=16384 0.00s user 0.57s system 7% cpu 7.517 total So as shown here, my test on an older 6.2 (with same patches) showed improved performance. But now on a new 6.2 build system, shows decreased performance. Nicole
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