Updating to ext4

We’ll start by telling the system to load the Ext4 driver instead of the Ext3 driver at boot.This will allow the system to boot and run normally for the steps that follow.Ext4 is the evolution of the most used Linux filesystem, Ext3.

updating to ext4-66

(Users running 9.04 are not affected by this.) Once it’s done, no more reboots are really necessary, though you can always reboot to make sure grub actually reinstalled correctly.

Files written from now on will be written with full Ext4 structures.

Now, run the following command to make the changes to your filesystem that adds the Ext4 features: ) Due to the changes that tune2fs made on your filesystem, when you reboot you’re going to get the message “Errors were detected on your filesystem, press ‘F’ to fix…” or something similiar. You may get the following error as well (I did): Just wait patiently.

You’re waiting for the changes to finish on the currently-processing filesystem, and it’s just telling you that it’s trying to mount or access /tmp and it’s having trouble, due to the currently-running process. Note that the partition number is omitted from the device path — this is intentional and correct.

The ext4 file system records information about when a file was last accessed and there is a cost associated with recording it. The default 5 sec means that if the power is lost, one will lose as much as the latest 5 seconds of work.

It forces a full sync of all data/journal to physical media every 5 seconds.

The filesystem will not be damaged though, thanks to the journaling.

The following fstab illustrates the use of Ext4 enables write barriers by default.

Edit the file /etc/fstab in your favorite text editor. # # proc /proc proc defaults 0 0 # /dev/sda1 UUID=327c1819-14e1-4b96-b9d2-d5e55e50f1ae / ext3 defaults,errors=remount-ro,relatime 0 1 # /dev/sda5 UUID=900e39f2-ad49-42ee-a7f5-8e6807d6b35b none swap sw 0 0 /dev/scd0 /media/cdrom0 udf,iso9660 user,noauto 0 0 ) After rebooting, the kernel will be using the Ext4 filesystem driver, even though your filesystem on disk is still natively ext3.

That’s what you want, you’ll be making the actual changes to the filesystem soon.

However, for partitions with size in the hundreds or thousands of GB and average file size in the megabyte range, this usually results in a much too large inode number because the number of files created never reaches the number of inodes.