Nilfs2: Fedora 13 Follow Up

As you might imagine, I have been running with F13 for a while now,
but I was too lazy to update the blog. In any case, I did run the
numbers on the Toshiba. They aren’t pretty:

Nilfs2:

$ dd if=/dev/zero of=./zeros.dat oflag=sync bs=4k count=1024
1024+0 records in
1024+0 records out
4194304 bytes (4.2 MB) copied, 3.6206 s, 1.2 MB/s
$ dd if=/dev/zero of=./zeros.dat oflag=sync bs=1024k count=4
4+0 records in
4+0 records out
4194304 bytes (4.2 MB) copied, 0.22621 s, 18.5 MB/s
$ dd if=/dev/zero of=./zeros.dat oflag=sync bs=1024k count=256
256+0 records in
256+0 records out
268435456 bytes (268 MB) copied, 15.2122 s, 17.6 MB/s

Ext4:

$ dd if=/dev/zero of=./zeros.dat oflag=sync bs=4k count=1024
1024+0 records in
1024+0 records out
4194304 bytes (4.2 MB) copied, 10.2423 s, 410 kB/s
$ dd if=/dev/zero of=./zeros.dat oflag=sync bs=1024k count=4
4+0 records in
4+0 records out
4194304 bytes (4.2 MB) copied, 0.204465 s, 20.5 MB/s
$ dd if=/dev/zero of=./zeros.dat oflag=sync bs=1024k count=256
256+0 records in
256+0 records out
268435456 bytes (268 MB) copied, 13.1899 s, 20.4 MB/s

I have no idea how to explain Ext4’s awful performance on small
blocks. However, the Intel/Ext4 combo won in just about every
category, so I’m keeping the Toshiba as the backup drive for now.

Interestingly, Nilfs2 performs better on the Toshiba than it does on
Intel. If we combine this with the observation that small block sizes
do relatively poorly on the Toshiba drive, than we have a pretty
convincing case that the Intel drive is doing some magic under the
covers to make it awesome on traditional filesystems, even at the
expense of filesystems specifically designed for SSDs.

In retrospect, I regret not trying out the other obvious filesystem,
btrfs. However that was never really in the running anyway, since I
can’t boot to a btrfs filesystem, even with Grub 2. Would have been
interesting to chart though.

Thus concludes my analysis of Nilfs2 for SSD. I encourage everyone with
an SSD to test, and get your results out there. Hopefully as Grub 2
matures and more distributions than Ubuntu use it, and as more SSDs
make it to the market, we can see what is really the fastest
filesystem out there.

Advertisements

Tags: , , ,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


%d bloggers like this: