Lustre discuss - Dec 2009 - WARNING: short read while accessing file >4GB on 32-bit client

Hi all,

A bug impacting 32-bit lustre clients has been identified in the most recent
1.8 releases. This issue manifests itself as a short read from files larger
than 4GB.

The problem is that, on the read path, the lustre client stores the file size
temporarily in a 32-bit variable (this happens only when a glimpse is
necessary). When an application then tries to read beyond the 4GB offset,
variable overflow occurs, resulting in a truncated read returned to the
application. To be clear, this is a client side issue and the file is not at
all corrupted on disk. 64-bit clients are not impacted by this problem.

This regression was introduced in 1.8.1 and will be resolved in 1.8.2 so also
affects 1.8.1.1. Releases 1.8.0.1 and prior (including 1.8.0) are unaffected.
A patch is available in bug 21506.

Best regards,
Johann

Thanks for letting us know.

Is there a website or newsgroup other than bugzilla to show us these
types of warnings and bugs and related patch/bugzilla entry?



On Wed, Dec 9, 2009 at 6:16 PM, Johann Lombardi <johann at sun.com>
wrote:
> Hi all,
>
> A bug impacting 32-bit lustre clients has been identified in the most
recent
> 1.8 releases. This issue manifests itself as a short read from files larger
> than 4GB.
>
> The problem is that, on the read path, the lustre client stores the file
size
> temporarily in a 32-bit variable (this happens only when a glimpse is
> necessary). When an application then tries to read beyond the 4GB offset,
> variable overflow occurs, resulting in a truncated read returned to the
> application. To be clear, this is a client side issue and the file is not
at
> all corrupted on disk. 64-bit clients are not impacted by this problem.
>
> This regression was introduced in 1.8.1 and will be resolved in 1.8.2 so
also
> affects 1.8.1.1. Releases 1.8.0.1 and prior (including 1.8.0) are
unaffected.
> A patch is available in bug 21506.
>
> Best regards,
> Johann
> _______________________________________________
> Lustre-discuss mailing list
> Lustre-discuss at lists.lustre.org
> http://lists.lustre.org/mailman/listinfo/lustre-discuss
>

On Thu, 2009-12-10 at 08:20 +0530, Mag Gam wrote: 
> Thanks for letting us know.
> 
> Is there a website or newsgroup other than bugzilla to show us these
> types of warnings and bugs and related patch/bugzilla entry?
lustre-announce and lustre-discuss is where we normally send these sorts
of notices.

b.

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On Thu, Dec 10, 2009 at 08:03:59AM -0500, Brian J. Murrell
wrote:
> On Thu, 2009-12-10 at 08:20 +0530, Mag Gam wrote: 
> > Thanks for letting us know.
> > 
> > Is there a website or newsgroup other than bugzilla to show us these
> > types of warnings and bugs and related patch/bugzilla entry?
> 
> lustre-announce and lustre-discuss is where we normally send these sorts
> of notices.
Actually, we are also considering adding such a page to the lustre wiki.
In addition to lustre mailing lists, you can also monitor bugs added
to the corruption tracker (bugzilla ticket #19512).

Cheers,
Johann

Hi!

On Thu, Dec 10, 2009 at 02:36:07PM +0100, Johann Lombardi
wrote:
> Actually, we are also considering adding such a page to the lustre wiki.
> In addition to lustre mailing lists, you can also monitor bugs added
> to the corruption tracker (bugzilla ticket #19512).
That a good hint, thanks! Unfortunately, the bug doesn''t seem to be
open for
public access. Is it intentional?

Regards,

Daniel.

Daniel

I have opened the tracker up. Be warned though, we use it to track any 
suspected corruption, even for future releases yet to be released and 
hardware\pilot errors also end up on there, so there will be some noise. 
When we have a confirmed corruption issue, we send out an alert to the 
Lustre mailing lists and also add to the headline on lustre.org (that is 
what Johann meant about the wiki).

Regards

PJones

Daniel Kobras wrote:
> Hi!
>
> On Thu, Dec 10, 2009 at 02:36:07PM +0100, Johann Lombardi wrote:
>   
>> Actually, we are also considering adding such a page to the lustre
wiki.
>> In addition to lustre mailing lists, you can also monitor bugs added
>> to the corruption tracker (bugzilla ticket #19512).
>>     
>
> That a good hint, thanks! Unfortunately, the bug doesn''t seem to
be open for
> public access. Is it intentional?
>
> Regards,
>
> Daniel.
>
> _______________________________________________
> Lustre-discuss mailing list
> Lustre-discuss at lists.lustre.org
> http://lists.lustre.org/mailman/listinfo/lustre-discuss
>

Hi Peter,

It seems it is not possible to add an email address in CC for this 
bugzilla #19512. Would it be possible to address this problem ?

Thank you
C?dric

Peter Jones a ?crit :
> Daniel
>
> I have opened the tracker up. Be warned though, we use it to track any 
> suspected corruption, even for future releases yet to be released and 
> hardware\pilot errors also end up on there, so there will be some noise. 
> When we have a confirmed corruption issue, we send out an alert to the 
> Lustre mailing lists and also add to the headline on lustre.org (that is 
> what Johann meant about the wiki).
>
> Regards
>
> PJones
>
> Daniel Kobras wrote:
>   
>> Hi!
>>
>> On Thu, Dec 10, 2009 at 02:36:07PM +0100, Johann Lombardi wrote:
>>   
>>     
>>> Actually, we are also considering adding such a page to the lustre
wiki.
>>> In addition to lustre mailing lists, you can also monitor bugs
added
>>> to the corruption tracker (bugzilla ticket #19512).
>>>     
>>>       
>> That a good hint, thanks! Unfortunately, the bug doesn''t seem
to be open for
>> public access. Is it intentional?
>>
>> Regards,
>>
>> Daniel.
>>
>> _______________________________________________
>> Lustre-discuss mailing list
>> Lustre-discuss at lists.lustre.org
>> http://lists.lustre.org/mailman/listinfo/lustre-discuss
>>   
>>     
> _______________________________________________
> Lustre-discuss mailing list
> Lustre-discuss at lists.lustre.org
> http://lists.lustre.org/mailman/listinfo/lustre-discuss
>
>
>

Oof, sorry about that. I have tweaked something else and proven this is 
sufficient by adding you to the cc list

C?dric Lambert wrote:
> Hi Peter,
>
> It seems it is not possible to add an email address in CC for this 
> bugzilla #19512. Would it be possible to address this problem ?
>
> Thank you
> C?dric
>
>
>