Re: [vserver] Possible Hashify Corruption - Update 2

From: Gordan Bobic <>
Date: Thu 21 Oct 2010 - 10:29:02 BST
Message-ID: <>

Herbert Poetzl wrote:
> On Wed, Oct 20, 2010 at 03:02:25PM +0100, Gordan Bobic wrote:
>> I have just tested this with a new kernel. And the issue doesn't arise
>> with! So it is definitely a kernel bug, most
>> likely in ext4.
>> This really needs to be documented and stressed on the pages with
>> download links. Hashify feature causes total data corruption with
>> when used on ext4 without a journal.
> well, thanks for investigating this, but you are
> aware that _nobody_ is supposed to use that kernel
> or patch anymore, as it was highly experimental
> (see the pre) and superceeded by a working version

That'd be fine if there was a non-pre patch available for that kernel -
but there isn't. And due to other patch requirements that may not have
been ported forward to new kernels, it is plausible that that somebody
might be stuck with it. I wasn't using such an old kernel out of choice.

If the patch shouldn't be used, it arguably shouldn't be linked on the
download page.

> in general, I'd stay away from kernels 2.6.25-2.6.31
> especially with 'sensitive' filesystems like ext4,
> reiserfs and btrfs ...

Agreed, but as I said, sometimes you don't have a choice.

>> I haven't tried other cases (ext4 with a journal or other file systems)
>> so I cannot speak for those, but in the mentioned use cases it is
>> completely repeatable.
> if the issue persists in the recent kernel branches,
> i.e. in or even 2.6.33.x/2.6.35.x then
> we need to investigate, otherwise I consider this
> closed ...

As I said, works fine. I'm not suggesting this should be
patched/fixed in vservers (I'm suspecting the bug is actually in ext4),
but I do think it should be documented. We are talking about the latest
available 2.5.30 kernel here (, which isn't that far off from Putting a note next to the link that says "there are known
issues with this kernel that can lead to file system corruption" would
go a long way toward saving people's data from stealthy corruption.
Having a warning where it's due on the download page is vastly
preferable to people writing on blogs things like "vservers sucks, it
corrupted my data".

Received on Thu Oct 21 10:29:11 2010

[Next/Previous Months] [Main vserver Project Homepage] [Howto Subscribe/Unsubscribe] [Paul Sladen's vserver stuff]
Generated on Thu 21 Oct 2010 - 10:29:13 BST by hypermail 2.1.8