This tutorial is all about how to convert an ext3 file system in linux to an ext4 file system without having any loss in data.You can also say that this article is about file system upgradation in linux without any data loss. Whenever you need to upgrade your linux file system from ext3 to ext4 you can upgrade it very easily without losing your data.
Here in this article i have mentioned step wise method to convert an ext3 file system to ext4 file system without any loss in data.
Note:I am performing this Lab on RHEL6 Linux.
Step1:Create a partition /dev/sda5 using fdisk
Step2:Update the partition table using below command if you are using RHEL6
#partx -v -a /dev/sda
Note;if you are using RHEL5 use partprobe command to update the partition table.
Step3:Format the partition /dev/sda5 using ext3 file system
Step4:create a directory /new
Step5: mount the newly created partition /dev/sda5 on /new using ext3 file system.
#mount -t ext3 /dev/sda5 /new
Step6: check the /dev/sda5 file sytem type and mount point
Step7: Now create some files on /dev/sda5
you can see i have created few files inside /new which is mounted on /dev/sda5.
Now i am goint to convert this ext3 file system to ext4
1.first we need to unmount it.
2.now convert it in to ext4 using tune2fs command
#tune2fs -O extents,uninit_bg,dir_index /dev/sda5
#fsck -pf /dev/sda5
#e2fsck -f /dev/sda5
3.now mount it on ext4 file system.
#mount -t ext4 /dev/sda5 /new
4.check whether it converted to ext4 or not using below command.
5.Now go to /new folder and check whether files created earlier are safe or not.
You will find that even after file system upgraded to ext4 from ext3 your data is safe. so no data loss at all.