Ubuntu with ext4 on SSD

[gvogs]

Hi!

I want to install my new pc with Ubuntu. I want to use ext4 on my SSD. Does it work? ext4 on SSD? Are there any Problems?

Nice day!

[MG&TL]

Wiki says that 'it can support everything an electromechanical device can do'

http://en.wikipedia.org/wiki/Solid-state_drive

I see no reason why not, although with a limited number of writes don't re-install Ubuntu too many times.

[cogier]

I am not yet convinced that 11.04 is the right version on Ubuntu for me and so I use 10.10 on my Dell XPS M1330 (ext 4) with a SSD drive and it works very well. Boot time (from pressing the "On" button to a usable desktop with the computer plugged into the mains) is 15 seconds. (20 seconds on battery).

Go for it!

[fcomstoc]

Hi!

I want to install my new pc with Ubuntu. I want to use ext4 on my SSD. Does it work? ext4 on SSD? Are there any Problems?

Nice day!

I have 2 SSD a 128gb and a 64gb I usually install Ubuntu to the 128 and create a swap partition on the 64; I have never had a problem with EXT3 or EXT4

[JRV]

This is a list of SSD tweaks gleaned from http://forum.eeeuser.com.



Four Tweaks for Using Linux with Solid State Drives

Published in September 4th, 2008
Posted by Tom in tips

SSDs (solid state drives) are great. They’re shock resistant, consume less power, produce less heat, and have very fast seek times. If you have a computer with an SSD, such as an Eee PC, there are some tweaks you can make to increase performance and extend the life of the disk.

1. The simplest tweak is to mount volumes using the noatime option.
By default Linux will write the last accessed time attribute to files.
This can reduce the life of your SSD by causing a lot of writes.
The noatime mount option turns this off.

Open your fstab file:
gksudo gedit /etc/fstab

Ubuntu uses the relatime option by default. For your SSD partitions (formatted as ext3),
replace relatime with noatime in fstab. Reboot for the changes to take effect.

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2. Using a ramdisk instead of the SSD to store temporary files will speed things up,
but will cost you a few megabytes of RAM.

Open your fstab file:
gksudo gedit /etc/fstab

Add this line to fstab to mount /tmp (temporary files) as tmpfs (temporary file system):

tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0

Reboot for the changes to take effect. Running df, you should see a new line with /tmp mounted on tmpfs:

tmpfs 513472 30320 483152 6% /tmp

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3. Firefox puts its cache in your home partition.
By moving this cache in RAM you can speed up Firefox and reduce disk writes.
Complete the previous tweak to mount /tmp in RAM, and you can put the cache there as well.

Open about:config in Firefox. Right click in an open area and create a new string value
called browser.cache.disk.parent_directory. Set the value to /tmp/$USER/firefox-tmp.

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4. An I/O scheduler decides which applications get to write to the disk when.
Because SSDs are so different than a spinning hard drive, not all I/O schedulers work well with SSDs.

The default I/O scheduler in Linux is cfq, completely fair queuing. cfq is works well on hard disks,
but I’ve found it to cause problems on my Eee PC’s SSD. While writing a large file to disk,
any other application which tries to write hang until the other write finishes.

The I/O scheduler can be changed on a per-drive basis without rebooting.
Run this command to get the current scheduler for a disk and the alternative options:

cat /sys/block/sda/queue/scheduler

You’ll probably have four options, the one in brackets is currently being used by the disk
specified in the previous command:

noop anticipatory deadline [cfq]

Two of these are better suited to SSD drives: noop and deadline.
Using one of these in the same situation, the application will still hang but only
for a few seconds instead of until the disk is free again. Not great, but much better than cfq.

Here’s how to change the I/O scheduler of a disk to deadline:

echo deadline > /sys/block/sda/queue/scheduler

(Note: the above command needs to be run as root, but sudo does not work with it on my system.
Run sudo -i if you have a problem to get a root prompt.)

You can replace sda with the disk you want to change, and deadline with any of the available schedulers.
This change is temporary and will be reset when you reboot.

If you’re using the deadline scheduler, there’s another option you can change for the SSD.
This command is also temporary and also is a per-disk option:

echo 1 > /sys/block/sda/queue/iosched/fifo_batch

You can apply the scheduler you want to all your drives by adding a boot parameter in GRUB.
The menu.lst file is regenerated whenever the kernel is updated, which would wipe out your change.
Instead of this way, I added commands to rc.local to do the same thing.

Open rc.local:
sudo gedit /etc/rc.local

Put any lines you add before the exit 0. I added six lines for my Eee PC,
three to change sda (small SSD), sdb (large SSD), and sdc (SD card) to deadline,
and three to get the fifo_batch option on each:

echo deadline > /sys/block/sda/queue/scheduler
echo deadline > /sys/block/sdb/queue/scheduler
echo deadline > /sys/block/sdc/queue/scheduler
echo 1 > /sys/block/sda/queue/iosched/fifo_batch
echo 1 > /sys/block/sdb/queue/iosched/fifo_batch
echo 1 > /sys/block/sdc/queue/iosched/fifo_batch

Reboot to run the new rc.local file.

[update] Commenter dondad has pointed out that it’s possible to add boot parameters
to menu.lst that won’t be wiped out by an upgrade. Open menu.lst (Remember to make a
backup of this file before you edit it):

sudo gedit /boot/grub/menu.lst

The kopt line gives the default parameters to boot Linux with. Mine looks like this:

# kopt=root=UUID=6722605f-677c-4d22-b9ea-e1fb0c7470ee ro

Don’t uncomment this line. Just add any extra parameters you would like.
To change the I/O scheduler, use the elevator option:

elevator=deadline

Append that to the end of the kopt line. Save and close menu.lst.
Then you need to run update-grub to apply your change to the whole menu:

sudo update-grub[end update]

Want to know how fast your SSD or other storage device is?
Using hdparm you can test the read performance of your disk:

sudo hdparm -t /dev/sda

The 4 GB SSD on my Eee PC 901 gets about 33 MB/s.
My desktop PC’s hard drive gets about 78 MB/s.
(What hdparm doesn’t show is that the seek time for an SSD is much, much lower than a hard disk.)


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Turn off Journaling in EXT4

First thing's first, we can confirm that our ext4 partition is running a journal with

sudo dumpe2fs /dev/sdaX | grep has_journal

Disabling journaling is rather easy, the only drag is that to make structural changes to a filesystem,
the filesystem cannot be mounted with read/write privileges. So, run a live cd and hit

sudo tune2fs -O ^has_journal /dev/sdaX

And it's done. Now when you boot, the change will be noted and the disk will be checked for errors.
When the system is finally up we can run this again to confirm that in fact ext4 is running without a journal

sudo dumpe2fs /dev/sdaX | grep has_journal

should now return nothing.

With this quick fix, no more constant IO peaks. I can now watch youtube videos without constant freezes.