> >>>>First on Ubuntu: > >>>>/dev/sda2 on / type ext3 (rw,relatime,errors=remount-ro) > >>>>~$ time (tar -zxf ports.tar.gz && sync) > >>>>real 0m47.784s
> >>>>Then the same commands on OpenBSD: > >>>>/dev/wd0k on /home type ffs (local, nodev, nosuid, softdep) > >>>>$ time (tar -zxf ports.tar.gz && sync) > >>>> 1m2.62s real 0m1.15s user 0m7.15s system > >>>So you have ~52 seconds on ext3 mounted 'realtime' (whatever that > >>>means), > >>>versus ~63 seconds on ffs mounted with 'softdep'. Replying to myself, 'realtime' implies noatime, says http://lwn.net/Articles/244829/ (Isn't "once upon atime" an amusing title?) And https://help.ubuntu.com/community/Fstab says that 'async' is the default for Ubuntu ext3 mounts. Is your ext3 mounted async? The mount line doesn't say so - but is that hidden under 'realtime', too? > Also, doesn't ext2/3 run with everything mount async? > A quick test with ffs in async mode (instead of, or added to softdep) > would also be worth running, in order to see how much "grossly insecure > I/O" lessens the perceived time. > I am one of those who like to keep my > files, so I wont recommend USING async, but for the sake of argument > here, such a test might be in order. softdep and async are mutually exclusive. This is what happens with and without noatime (+ softdep, of course), and with async replacing softdep, on my machine: # uname -a OpenBSD stary.dhcp.fjfi.cvut.cz 4.4 GENERIC.MP#2 i386 # mount /dev/wd0a on / type ffs (local) /dev/wd0d on /usr type ffs (local, nodev, softdep) /dev/wd0e on /var type ffs (local, nodev, nosuid, softdep) /dev/wd0f on /var/log type ffs (local, nodev, nosuid, softdep) /dev/wd0g on /var/mail type ffs (local, nodev, nosuid, softdep) /dev/wd0h on /tmp type ffs (local, nodev, nosuid, softdep) /dev/wd0i on /home type ffs (local, nodev, nosuid, softdep) /dev/wd0k on /dload type ffs (local, nodev, nosuid, softdep) /dev/wd0j on /backup type ffs (local, nodev, nosuid, softdep) # cd /backup # ls -l ports.tar.gz -rw-r--r-- 1 root wheel 14583699 Aug 9 2008 ports.tar.gz # time { tar xzf ports.tar.gz ; sync ; } 1m5.51s real 0m0.00s user 0m0.00s system # time rm -rf ports 0m13.88s real 0m0.20s user 0m1.56s system # cd # umount /backup # mount -o nodev,nosuid,softdep,noatime /dev/wd0j /backup # cd /backup # time { tar xzf ports.tar.gz ; sync ; } 1m6.85s real 0m0.00s user 0m0.00s system # time rm -rf ports 0m14.72s real 0m0.16s user 0m1.33s system # cd # umount /backup # mount -o nodev,nosuid,async /dev/wd0j /backup # cd /backup # time { tar xzf ports.tar.gz ; sync ; } 0m39.44s real 0m0.00s user 0m0.01s system # time rm -rf ports 0m6.80s real 0m0.19s user 0m1.45s system Jan
