# [solved]converting ext3 to ext4

## m0021

hi,

because of some new features and little better speed i changed my root filesystem from ext3 to ext4.

first i changed ext3 to ext4 in fstab, then i booted with minimal installcd and did 

tune2fs -O extents,uninit_bg,dir_index /dev/sda1 

(as described in http://en.gentoo-wiki.com/wiki/Ext4#Converting_an_ext3_filesystem_to_ext4)

after that i did

fsck -f /dev/sda1

got some errors, fixed it.

now when i boot my ext4 system i get 

```
Jul 20 12:55:45 gentoo2 kernel: VFS: Mounted root (ext2 filesystem) readonly on device 8:1.
```

in var/log/kern.log

mount says the same

```
/dev/root on / type ext2 (rw,noatime,barrier=1,data=ordered)
```

why ext2? what went wrong?Last edited by m0021 on Tue Jul 20, 2010 3:21 pm; edited 1 time in total

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## nutbar21

What kernel version are you running?  Is it safe to assume you activated the appropriate configs in your kernel and rebuilt correctly?

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## m0021

i'm running kernel version 2.6.34-r2 with ext4 support built-in

edit:

disabling the feature where ext4 can mount ext2/ext3 in kernel solved the problem

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## gentoo_ram

Add the command line parameter "rootfstype=ext4" to the kernel command line in your GRUB config.

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