Re: BUG EXT3-fs: fragsize 1024 != blocksize 4096 (unsupported)

[tytso@mit.edu]

On Tue, Apr 06, 2010 at 10:05:52PM +0200, Jan Kara wrote:
> On Tue 06-04-10 21:35:09, Oscar Megia wrote:
> > Yes, it was a problem with the ATX power supply. I replaced it and now
> > is working fine.
> > 
> > I did what you told and I recover my important data but not all fs.
> > 
> > The matter is if you have a hardware fault the ext3 journal fs don't
> > preserve your data.
> > 
> > I'm not an expert about the journal ext3 fs but I though is designed
> > to preserve data so if the HD has a fault, ext3 must preserve your
> > data. If the fault is during updating the main fs it must go to the
> > previous main fs. This could happen when there is a power cut.
>   Ext3 journal prevents filesystem corruption only in case the power
> fails suddently. Also cases like kernel crashes are usually solved by the
> journal quite fine. But in situations like flaky power supply where memory
> can provide wrong data to disk or disk writes only some data because of
> weak voltage, journaling does not help at all. Generally, only good backups
> are a solution to bugs in HW...

This is all true.  However, e2fsck should have been able to use a
duplicate superblock, and fix at least the fragsize 1024 != blocksize
4096 problem.  Depending on how much damage was done to the disk by
the flaky power supply, you might not recover all of your data, but
usually e2fsck can help you recover at least some of your files....

You might have to run it from a rescue CD if your root filesystem is
badly scrambled, though.

	       	   	    	       - Ted