Date: Fri, 22 Oct 2004 19:34:25 +0200 From: fandino <fandino@ng.fadesa.es> Cc: freebsd-current@freebsd.org Subject: Re: FreeBSD 5.3b7and poor ata performance Message-ID: <417944A1.4070707@ng.fadesa.es> In-Reply-To: <20041022164743.C6A3D5D04@ptavv.es.net> References: <20041022164743.C6A3D5D04@ptavv.es.net>
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Kevin Oberman wrote:
>>>OpenBSD 3.5:
>>>
>>>dd if=3D/mnt/aa of=3D/dev/null bs=3D1024k count=3D1024
>>>1024+0 records in
>>>1024+0 records out
>>>1073741824 bytes transferred in 18.743 secs (57287584 bytes/sec)
>>>
>>>
>>>FreeBSD 5.3rc1:
>>>
>>># dd if=3D/mnt/aa of=3D/dev/null bs=3D1024k count=3D1024
>>>1024+0 records in
>>>1024+0 records out
>>>1073741824 bytes transferred in 42.215597 secs (25434719 bytes/sec)
>>
>>BTW, others have asked that you not use dd as your "benchmark",
>>because it's not benchmarking anything relevant for real-world use of
>>the disk.
>
>
> While it is not typical of many "real-world" uses, I back up my laptop
> by copying the disk with dd(1). It used to take me about 40 minutes with
> V4. Now it takes just over an hour. This 25 minutes lost every day is a
> very real part of my world.
Same here. At work I use dd to backup last valid operating system
on the computer for easy recovery. It's a complement (not suplement)
of tape, library, etc backups. Also, OpenBSD "altroot" is a nice idea.
# If ROOTBACKUP is set to 1 in the environment, and
# if filesystem named /altroot is type ffs, on /dev/* and mounted "xx",
# use it as a backup root filesystem to be updated daily.
[ "X$ROOTBACKUP" = X1 ] && {
rootdev=`awk '$2 == "/" && $1 ~ /^\/dev\// && $3 == "ffs" && \
$4 ~ /rw/ \
{ print substr($1, 6) }' < /etc/fstab`
rootbak=`awk '$2 == "/altroot" && $1 ~ /^\/dev\// && $3 == "ffs" && \
$4 ~ /xx/ \
{ print substr($1, 6) }' < /etc/fstab`
[ X$rootdev != X -a X$rootbak != X ] && {
sync
echo ""
echo "Backing up root filesystem:"
echo "copying /dev/r$rootdev to /dev/r$rootbak"
dd if=/dev/r$rootdev of=/dev/r$rootbak bs=16b seek=1 skip=1 \
conv=noerror
fsck -y /dev/r$rootbak
}
}
> I also bothers me to see this significant deterioration on what appears
> to be a VERY simple disk activity. I'd like to benchmark buildworld, but
> doing that with different versions is not so easy. I might try building
> jdk. That is very "real-world".
It'd be interesting if you run some real world test. i.e. copy a big file
and compare times between F4 and F5
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