# unknown filesystem type 'ext2' [SOLVED]

## rawbeefman

An interesting problem I have.  I just upgraded my kernel after not using my mythbox for the summer.  I rebooted, recompiled with more options, went to copy it over, and I find that /boot was not mounted.  I went to mount it and received the error 

```
unknown filesystem type 'ext2'
```

Now, I cannot boot another kernel since I deleted the old one.  oops.  Ext2 is explicitly in the kernel.  I dont have a dvd drive on my mythbox so I cant fix from a liveCD.

Is there any way to fix this issue?  Thank you.

 - EhrenLast edited by rawbeefman on Sun Sep 07, 2008 12:53 am; edited 1 time in total

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## cst

seems you dont have ext2 support enabled in the kernel

are any other filesystems recognized?

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## rawbeefman

Yes, everything but ext2.  Which is weird because it is enabled in the config file.

My question is how to I manually get and load that module?

Thanks.

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## cst

the one thing that comes to mind is to use different kind of partition for your /boot if you have a one to spare and install everything needed to boot there.

To have a module you would need to actually compile it with from the kernel sources.

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## rawbeefman

That sucks.  Is there a way I can preserve that data?  Can I make it an ext3 partition and preserve it.

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## zyko

I think you can convert ext2 --> ext3 by simply adding a journal. I'm pretty sure this is safe, but I don't know if it works when the kernel claims it doesn't know ext2 (since it probably can't write the journal to the disk).

The command I'm thinking of is 

```
tune2fs -O has_journal /dev/sdf9
```

Replace /dev/sdf9 with your actual partition, of course.

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## Hu

How did you delete the old kernel if you did not have /boot mounted?  Typically, the kernel would be in /boot, so if you cannot mount it, then the old kernel should still be there.

You could recover from this by moving the hard drive to a system with a kernel that recognizes ext2 or by PXE booting the offending system so that you can deliver a good kernel over the network.  Before going any further, I would check that the /boot partition is still sane.  Use file to check that it has the right magic numbers, and use e2fsck to check it for corruption.  If you find any corruption, abort the fsck and make a bit-for-bit backup before proceeding.

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## rawbeefman

Hyko, I see what you're saying, but I dont have the resources to pull it off (new apartment, new state). 

But ZYKO, you are the MAN.  I was able to convert it, so I mounted and it worked great.  Thanks a bunch.  Marking as solved.

 - Ehren

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## sluys

 *zyko wrote:*   

> The command I'm thinking of is 
> 
> ```
> tune2fs -O has_journal /dev/sdf9
> ```
> ...

 

Thanks, I ran into the same problem and this helped me out.  I wanted to add that you may want to turn your boot partition back to ext2 after you're done installing your new kernel with ext2 support:

```
tune2fs -O ^has_journal /dev/sdf9
```

Also, an alternative would be to select ext2 support in the kernel as a module, and

```
make && make modules_install

modprobe ext2
```

That should allow you mount /boot.  You can then either build ext2 support into the kernel, or simply load the module (by hand or at boot time).

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## cach0rr0

I've not asked, but I still don't know why ext2 support is deselected by default in the config recently

as well, it doesnt jump out at you because it's labeled "seconded extended file system" instead of simply "ext2"

understood that's its long, proper name, but annoying nonetheless. 

It is natural for one's eyes to skim and skip right over 'second extended file system', and just assume ext2 is built in

perhaps wrong, but natural nonetheless

on that same token, i can guarantee if i saw 'ext2' unchecked, I would definitely not skip over it. 

Wish they'd change that - or maybe do the long name in parethesis e.g. "ext2 (second extended file system)"

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## qcaze

 *cach0rr0 wrote:*   

> I've not asked, but I still don't know why ext2 support is deselected by default in the config recently
> 
> as well, it doesnt jump out at you because it's labeled "seconded extended file system" instead of simply "ext2"
> 
> understood that's its long, proper name, but annoying nonetheless. 
> ...

 

I also had the "unknown filesystem type 'ext2'" error - thanks for helping!

I'm a long time gentoo user who have just installed a new machine, and I too skipped the "second extended file system" label in kernel menuconfig - which makes no sense (and should be on by default), since ext2 is used in the install docs for the boot partition and ext3 is correctly named, well, ext3.

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## azote

crap same thing happen to me ... thank god for the easy convert ext2-->ext3  :Wink: 

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## cloudcode

thanks!

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