Hi...
Well, I finally had the time to check ext2 and ext3 througput on my drives...
And as I was afraid, I was comparing apples and oranges. I have done the check
on a single disk, mounting and unmounting the disk to clear caches and so on.
The result is that ext3 reads the same amount of data int the same time.
So I still do not understand why cdrecord failed. Is there any utility to mesaure
sustained speed (and variance) ?
The script is like:
PART=/dev/sda5
MB=500
for fs in ext2 ext3
do
echo "================================================================"
echo "fs="$fs
cd /
umount /mnt/disk
case $fs in
ext2)
mount -t $fs $PART /mnt/disk
;;
ext3)
mount -t $fs -o data=writeback $PART /mnt/disk
;;
esac
cd /mnt/disk
echo "write:"
rm -f foo
time dd if=/dev/zero of=foo bs=1024k count=$MB
echo "sync:"
time sync
echo "read:"
time cat foo > /dev/null
rm -f foo
echo "================================================================"
done
sda is a IBM DDYS-T09170N (scsi3, U160), sdb is a IBM DCAS-34330W (scsi2, UW),
hanged on a 7890 (U2W), so bus speed for sda is 80Mb/s, and for sdb is 40Mb/s.
Kernel is 2.4.15-pre4.
Results are similar to this sample:
/dev/sda5 (ultra160 running at 80):
================================================================
fs=ext2
write:
500+0 records in
500+0 records out
0.00user 4.14system 0:15.76elapsed 26%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (120major+20minor)pagefaults 0swaps
sync:
0.00user 0.11system 0:10.15elapsed 1%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (95major+17minor)pagefaults 0swaps
read:
0.18user 3.45system 0:22.43elapsed 16%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (100major+19minor)pagefaults 0swaps
================================================================
================================================================
fs=ext3
write:
500+0 records in
500+0 records out
0.00user 8.34system 0:17.84elapsed 46%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (120major+20minor)pagefaults 0swaps
sync:
0.00user 0.12system 0:10.61elapsed 1%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (95major+17minor)pagefaults 0swaps
read:
0.19user 4.10system 0:22.44elapsed 19%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (100major+19minor)pagefaults 0swaps
================================================================
/dev/sdb1 (wide at 40):
================================================================
fs=ext2
write:
500+0 records in
500+0 records out
0.01user 4.20system 0:37.03elapsed 11%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (120major+20minor)pagefaults 0swaps
sync:
0.00user 0.07system 0:29.76elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (95major+17minor)pagefaults 0swaps
read:
0.21user 2.97system 1:05.17elapsed 4%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (100major+19minor)pagefaults 0swaps
================================================================
================================================================
fs=ext3
write:
500+0 records in
500+0 records out
0.01user 7.91system 0:41.96elapsed 18%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (120major+20minor)pagefaults 0swaps
sync:
0.00user 0.08system 0:28.87elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (95major+17minor)pagefaults 0swaps
read:
0.18user 4.43system 1:05.78elapsed 7%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (100major+19minor)pagefaults 0swaps
================================================================
-- J.A. Magallon # Let the source be with you... mailto:jamagallon@able.es Mandrake Linux release 8.2 (Cooker) for i586 Linux werewolf 2.4.15-pre4-beo-2 #1 SMP Thu Nov 15 13:02:43 CET 2001 i686 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Thu Nov 15 2001 - 21:00:45 EST