HOWTO: Tweak your ext3 filesystem for a performance boost

[GoldBuggie]

If the /etc/fstab file is for static drives. Where's the equivalent file for hotplug USB drives for example?? I want to make this change to my storage drives, as others have recommended doing.. But they're USB and don't show up in fstab when mounted..

I would change the options in hal for this. If I remember correctly it is the file /usr/share/hal/fdi/policy/10osvendor/10-storage-policy.fdi which you need to change for this. Don't remember all the details. You will have to look it up in the manual for hal. Sorry that I can't be of more assistant here but it takes some time going thrue the hal info.

I'm going to try this on my computer over the weeked. I also have a super old Thinkpad 380ED which I'm fixing up for a friend. I've got Mepis on it, will this work on other distro's too?

Yes it will work on other distro's. It is a filesystem thingy. Hence it will work on all linux.

[autocrosser]

Thanks Goldbuggie--I'm having some kernel problems in Dapper right now (still at the -15-11-smp)--So I can change my vmlinux-old & keep that unchanged for a while. I'll give it a go this weedend.....

Well..just changing your fstab will probably work but to answer your question: change the kernel line.(but this option will then get removed when updating your kernel)

 kernel          /boot/vmlinuz-2.6.12-10-686 root=/dev/hda1 ro quiet splash vga=792 devfs=mount rootflags=data=writeback

[dcstar]

.......
Ext3 & ReiserFS has three kinds of journaling methods:
1) Journal Data Writeback
2) Journal Data Ordered
3) Journal Data

I don't want to explain them to much here but the difference of the three is when the actual data is written to the filesystem in relation to the metadata and its entrance into the journal.
.......

For anyone that cares about the three different options:

(Taken from http://www.nyx.net/~sgjoen/disk-5.html)
--------
Metadata, data that describes the structure of the files, is written in a journal to the disk. Note that there are 3 modes of operations for ext3fs.

data=writeback

This is metadata-only journalling. File data is written back to the main fs lazily.

After a crash and recovery the file integrity is intact but file content can be old.

Normally this is the fastest mode.

data=ordered

Here file data is written before metadata.

After a crash and recovery the file integrity is intact and files contain correct, recent data.

Normally this is only slightly slower.

data=journal

All data (as well as to metadata) is written to the journal before it is released to the main fs for writeback.

This is a specialised mode for cases where synchronous operations are required, such as for mail spools and synchronous NFS mounts.
--------

[Mortimer]

This went smoothy for me, no problems. What I recommend for beginners is to do it all exactly.

As far as the performance increase, it's hard to say if opening files is faster, because I don't think it is. Writing a lot of tiny files rapidly seems faster, though.

[cws]

I first tested this on my Ubuntu test machine (laptop) and everything went well. Then I unfortunately had the guts to apply this on my main Ubuntu desktop.

I did everything exactly like advised. When I rebooted, something went wrong. Some services (calculating module dependencies, network, loading modules) failed to start and it got completely stucked when trying to start the Log daemon.

Then I rebooted to recovery mode to undo the changes made to fstab and menu.lst. But in my /etc/fstab is a line "errors=remount-ro". So now the whole hda1 is read-only and I can't make any changes to those files. I'm sure there is a simple solution to this but I don't know what it is...

In spite of all, thanks for the howto. It atleast speeded up my laptop

EDIT:

# mount -o remount,rw /

did for me.

[duffydack]

I have an external usb HD, i think its using write caching, how do i turn this off. The windows equivalent to "optimise for quick removal" is what im looking for.

[RAOF]

I get the same error message as noted in this thread:

th@ubuntu:~$ sudo tune2fs -o journal_data_writeback /dev/hda1
tune2fs 1.38 (30-Jun-2005)
tune2fs: Bad magic number in super-block while trying to open /dev/hda1
Couldn't find valid filesystem superblock.

Note that this is on a reiserfs partition, hda1 is correct.

I did, however, get this to work on my desktop's ext3 partition, i noticed a huge speed improvement when using apt-get and synaptic, small improvements elsewhere. A straight up $cp stuff/ ~/Desktop/ took exactly the same amount of time, stuff/ had 1400 files and was 240MB.

The reason why this doesn't work for reiserfs partitions is that "tune2fs" is the ext2/ext3 tuning program. "reiserfstune" is the one you want for reiserfs, and it doesn't support the "-o journal_data_writeback" option. In fact, it doesn't seem to support changing the journal style at all. Maybe it doesn't need to be changed on-disc.

[GoldBuggie]

The reason why this doesn't work for reiserfs partitions is that "tune2fs" is the ext2/ext3 tuning program. "reiserfstune" is the one you want for reiserfs, and it doesn't support the "-o journal_data_writeback" option. In fact, it doesn't seem to support changing the journal style at all. Maybe it doesn't need to be changed on-disc.

I've tested the howto for reiserfs without using any tune2fs similar command and it worked for me.

[ashrack]

I've tested the howto for reiserfs without using any tune2fs similar command and it worked for me.

M2

[oleoleole]

Ohh, this worked nice. And I'm was following the HowTo.

Here is my setup, since I run more than 1 partitition.

For the root-partitition options in fstab, it's enough with this line:

/dev/hde1 / ext3  defaults,errors=remount-ro,noatime,data=writeback 0 1

defaults = Uses the default options that are rw, suid, dev, exec, auto, nouser, and async. Source: http://www.tuxfiles.org/linuxhelp/fstab.html

Since I've got more than one partitition, I added this in my /etc/fstab to:

/dev/hde5 /home ext3 defaults,noatime,data=writeback 0 2
/dev/hdf1 /home/ole/warez/videodisk1 ext3 defaults,noatime,data=writeback 0 2

And I did:

sudo tune2fs -o journal_data_writeback /dev/hde5; tune2fs -o journal_data_writeback /dev/hdf1
sudo tune2fs -l /dev/hde5 | grep "mount options"
sudo tune2fs -l /dev/hdf1 | grep "mount options"

And everything seems to work just fine.

You should be seing this line after doing the "tune2fs -l"

root@propell:/home/ole# tune2fs -l /dev/hdf1 | grep "mount options"
Default mount options:    journal_data_writeback