Re: Dealing with ext3 and sparse_super

[Szakacsits Szabolcs]

Hello,

On Thu, 5 May 2005 address@hidden wrote:

> I've been making some tests with parted software lately.

Interesting observations.

> No errors. Remounted the resized partition and checked again all files 
> making md5sums of them. The data on the filesystem remained unchanged.

Please note, that "worked for me" doesn't necessarily mean it will work
for everybody. However I think the sparse_super feature is a very good 
candinate for this and you made the first and successful step to prove
this to be right.

In this case the problem can manifest, for instance, when one lost or 
corrupted his/her superblock and ext3 wants to recover it by using other 
ones however this would fail because an earlier parted ext3 resize 
incorrectly handled the sparse_super feature.

> Making a ext3 filesystem with mkfs.ext3, and then using tune2fs -O 
> ^sparse_super doesn't solve the problem, as parted will remain 
> complaining about 'strange layout'.

e2fsck must be run after this. As the man page says:

       After  setting  or clearing sparse_super and filetype filesystem
       features, e2fsck(8) must be run on the filesystem to return the
       filesystem  to a consistent state.  Tune2fs will print a message
       requesting that the system administrator run e2fsck(8) if neces-
       sary.

Cheers,
        Szaka