Second Block on Partition overwritten with 0xFF

Tomas Pospisek ML tpo2 at
Thu Sep 6 10:09:12 UTC 2007

On 9/6/2007, "Theodore Tso" <tytso at> wrote:

>On Wed, Sep 05, 2007 at 08:58:15AM +0000, Tomas Pospisek ML wrote:
>> Can anybody here give me a hint about the problem? Particulary:
>> > My question is: does the ext3 driver _ever_ write outside of its own
>> > space on disk - i.e into 0x000-0x400? That is can we exclude with
>> > certainity that it's _not_ the ext3 driver causing the problem?
>The ext3 driver physically can not write outside of its space on disk,
>since it accesses it via some device whose boundaries are defined by
>the partition table, for example, /dev/hda2.

Yes, however, as I read in [1] *each* partition with an ext2/3 FS on it
starts with a boot sector, and the first block group starts (per
default) at 0x400. Thus as I understand it, it *would* be possible for
the ext3 driver to pysically write to those first sectors inside its

Does the ext2/3 driver *ever* touch anything before the first block group?

>>From what you describe, I would certainly be suspicious of the CF

Well I certainly am, however I am not able to find any way forward to be
able to point my finger on it.

[1] (chapter "Physical

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