[Gluster-users] file corruption on Gluster 3.5.1 and Ubuntu 14.04

[mike]

Any more to this thread? I don't mean to nag, but this seems like a pretty serious issue.

How can I help?

On Sep 7, 2014, at 9:51 AM, mike <mike at luminatewireless.com> wrote:

> I don't think I have these enabled. How can I confirm that?
> 
> On Sep 7, 2014, at 12:57 AM, Anand Avati <avati at gluster.org> wrote:
> 
>> The only reason O_APPEND gets stripped on the server side, is because of one of the following xlators:
>> 
>> - stripe
>> - quiesce
>> - crypt
>> 
>> If you have any of these, please try unloading/reconfiguring without these features and try again.
>> 
>> Thanks
>> 
>> 
>> On Sat, Sep 6, 2014 at 3:31 PM, mike <mike at luminatewireless.com> wrote:
>> I was able to narrow it down to smallish python script.
>> 
>> I've attached that to the bug.
>> 
>> https://bugzilla.redhat.com/show_bug.cgi?id=1138970
>> 
>> 
>> On Sep 6, 2014, at 1:05 PM, Justin Clift <justin at gluster.org> wrote:
>> 
>> > Thanks Mike, this is good stuff. :)
>> >
>> > + Justin
>> >
>> >
>> > On 06/09/2014, at 8:19 PM, mike wrote:
>> >> I upgraded the client to Gluster 3.5.2, but there is no difference.
>> >>
>> >> The bug is almost certainly in the Fuse client. If I remount the filesystem with NFS, the problem is no longer observable.
>> >>
>> >> I spent a little time looking through the xlator/fuse-bridge to see where the offsets are coming from, but I'm really not familiar enough with the code, so it is slow going.
>> >>
>> >> Unfortunately, I'm still having trouble reproducing this in a python script that could be readily attached to a bug report.
>> >>
>> >> I'll take a crack at that again, but I will a file a bug anyway for completeness.
>> >>
>> >> On Sep 5, 2014, at 7:10 PM, mike <mike at luminatewireless.com> wrote:
>> >>
>> >>> I have narrowed down the source of the bug.
>> >>>
>> >>> Here is an strace of glusterfsd http://fpaste.org/131455/40996378/
>> >>>
>> >>> The first line represents a write that does *not* make it into the underlying file.
>> >>>
>> >>> The last line is the write that stomps the earlier write.
>> >>>
>> >>> As I said, the client file is opened in O_APPEND mode, but on the glusterfsd side, the file is just O_CREAT|O_WRONLY. The means the offsets to pwrite() need to be valid.
>> >>>
>> >>> I correlated this to a tcpdump I took and I can see that in fact, the RPCs being sent have the wrong offset.  Interestingly, glusterfs.write-is-append = 0, which I wouldn't have expected.
>> >>>
>> >>> I think the bug lies in the glusterfs fuse client.
>> >>>
>> >>> As to your question about Gluster 3.5.2, I may be able to do that if I am unable to find the bug in the source.
>> >>>
>> >>> -Mike
>> >>>
>> >>> On Sep 5, 2014, at 6:16 PM, Justin Clift <justin at gluster.org> wrote:
>> >>>
>> >>>> On 06/09/2014, at 12:10 AM, mike wrote:
>> >>>>> I have found that the O_APPEND flag is key to this failure - I had overlooked that flag when reading the strace and trying to cobble up a minimal reproduction.
>> >>>>>
>> >>>>> I now have a small pair of python scripts that can reliably reproduce this failure.
>> >>>>
>> >>>>
>> >>>> As a thought, is there a reasonable way you can test this on GlusterFS 3.5.2?
>> >>>>
>> >>>> There were some important bug fixes in 3.5.2 (from 3.5.1).
>> >>>>
>> >>>> Note I'm not saying yours is one of them, I'm just asking if it's
>> >>>> easy to test and find out. :)
>> >>>>
>> >>>> Regards and best wishes,
>> >>>>
>> >>>> Justin Clift
>> >>>>
>> >>>> --
>> >>>> GlusterFS - http://www.gluster.org
>> >>>>
>> >>>> An open source, distributed file system scaling to several
>> >>>> petabytes, and handling thousands of clients.
>> >>>>
>> >>>> My personal twitter: twitter.com/realjustinclift
>> >>>>
>> >>>
>> >>
>> >
>> > --
>> > GlusterFS - http://www.gluster.org
>> >
>> > An open source, distributed file system scaling to several
>> > petabytes, and handling thousands of clients.
>> >
>> > My personal twitter: twitter.com/realjustinclift
>> >
>> 
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>> 
> 

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