# convert ext3 to ext4 without journaling (SSD)

## jeanluca

Hi All

currently I have ext3 on a SSD, so I want to convert it to ext4 without journaling.

So far I found, for the conversion

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

Which I haven't done yet. First I would like to know how to disable 'journaling', any suggestions ?

My kernel (2.6.30-gentoo-r7) config for ext4 looks like

 *Quote:*   

> CONFIG_EXT4_FS=y
> 
> # CONFIG_EXT4DEV_COMPAT is not set
> 
> CONFIG_EXT4_FS_XATTR=y
> ...

 

cheers

LuCa

----------

## jeanluca

I found out that -O ^has_journal might turn journaling off

Unfortunately, the tune2fs didn't recognize the other options so I have done the following

```
tune2fs -O ^has_journal /dev/sdb1
```

Now, I get some errors during boot, and it takes a couple of minutes at the point where it says 'Remounting filesystem .... read/write'

But at the end I get the login prompt and everything seems to work

Does anybody know what the consequences are of ommitting extents,uninit_bg,dir_index ?

And how can I verify that journaling is indeed switched off ?

thx

LuCa

----------

## mv

 *jeanluca wrote:*   

> Does anybody know what the consequences are of ommitting extents,uninit_bg,dir_index ?

 

It means that you are not using the main new features of ext4, so you could probably mount with ext2 as well (actually, I would suggest that you use ext2 instead of ext4 when you are not interested in ext4's other features anyway).

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## jeanluca

I am interested in ext4 features, except journaling! ext4 should be faster than ext2 and ext3

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## mv

 *jeanluca wrote:*   

> ext4 should be faster than ext2 and ext3

 

Perhaps the extents make it slightly faster, although I doubt that this makes a difference for SSD. dir_index might be an improvement when you have long directories, but AFAIK you can also use them with ext2 (not sure; you should not rely on this information). And other improvements like more accurate time will certainly not increase the speed (BTW, this would also require to change the inode size and a lot of write-operations would be necessary for that conversion which is perhaps not a good idea for SSD). Of course, you can use the ext4 driver without making use of any of that features.

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## Simba7

I would suggest btrfs since it supports SSDs.

I've been using it for months without issues.

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## jeanluca

I've just managed to run

```
$> tune2fs -O extents,uninit_bg,dir_index,^has_journal /dev/sda3

$> fsck.ext4 -yfD /dev/sda3

$> fsck.ext4 -yfD /dev/sda3

```

with succes

I've never heard of btrfs (sounds interesting!), so is it possible to move from ext4 to btrfs (any docs?)

cheers

LuCa

ps how can you see if journaling is on or off ?

UPDATE: I think I found what I was looking for:

```
$> grep journal /var/log/messages

.....

Nov  2 02:01:07 www [    0.667047] EXT4-fs: mounted filesystem sda3 without journal

Nov  2 02:01:07 www [    2.610457] EXT4 FS on sda3, no journal

.....

```

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## Veldrin

 *Quote:*   

> I've never heard of btrfs (sounds interesting!), so is it possible to move from ext4 to btrfs (any docs?) 

 

Not in the way, that one can move from ext2 to ext3 to ext4....

btrfs is an entirely different FS. Moving from ext4 to btrfs is like moving from xfs to reiser4 (probably not the best example; in short not possible)

You have to create a new filesystem, and then copy all data over...

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## gringo

not that i tested myself but according to the btrfs wiki it is possible to move from ext3 ( or ext4) to btrfs :

http://btrfs.wiki.kernel.org/index.php/Conversion_from_Ext3

if you do, make sure you have backups of course, btrfs is marked experimental and might eat your data for lunch if you aren´t carefull !

cheers

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## Veldrin

I take everything back....

And if you go to the discussion page, you see, that this should be even possible with ext4.

----------

