Re: Reproducible filesystem corruption in lenny
On Tue, Jul 28, 2009 at 10:33 AM, Sven Joachim<email@example.com> wrote:
> On 2009-07-28 15:42 +0200, Josh Kelley wrote:
>> Turning off has_journal or adding -o data=journal fixes the
>> immediately preceding problem. (I haven't tested it for our cloning
>> procedure.) However, I don't want to go back to ext2, and
>> data=journal seems to be barely documented. (What exactly does it
> Quoting mount.8:
> All data is committed into the journal prior to being
> written into the main file system.
> In other words, your data are written to disk twice.
Thank you. I also found this web page explaining data=journal in more detail:
> I would suggest testing the flash drives with different filesystems
> under different operating systems. Fill it up completely, re-plug the
> device, read the data back and compare to the original.
> There had been cases of USB memory sticks with manipulated controllers
> produced by fraudulent manufacturers. These sticks reported a higher
> capacity than they really had. They never reported read or write
> errors, but once you filled more than half of the reported capacity, all
> writes would go to the same sectors, producing massive data and
> filesystem corruption. I had bought such a scam product myself, and it
> cost me many hours of grief.
I tested one of the problematic drives under Windows with FAT32 and
had no problems filling the entire contents, so that doesn't seem to
be what's happening here.