Re: Unstableness in grant table block drivers

[Anthony Liguori <aliguori@us.ibm.com>]

Christopher Clark wrote:

>Hello Anthony
>
>First off, hands up: this was my code and I just didn't get around to
>sending the mail to the list as I had enough to deal with relocating
>from the UK to the US last week. The code was, however, tested under
>load and working fine, and I did consider it to be ready for wider
>testing in unstable.
>  
>
Hi Christopher,

My note was more of a suggestion for the future than a complaint.  You 
guys in Cambridge move very quickly and it's hard for some of us outside 
to keep up :-)  You guys just keep churning out cool stuff.

>The machines you can't get to start domUs, and symptom of not finding
>the root filesystem is exactly what you'd see if your dom0 and domU
>configs don't match; either both or neither need to be using grant
>tables for transport. Your other issues will need more investigation,
>and a reproducable scenario would be extremely helpful indeed.
>  
>
Actually, this seems like it might be a common thread between all of our 
scenarios.  I'm using (and I assume others) a standard dom0 config file 
that has all of my hardware enabled while I just use the default config 
file for domU.

I'll try to confirm this tomorrow with the other people that were 
experiencing problems.  Perhaps I'll run a copy of fsstress too and let 
you guys know the results.

Regards,
Anthony Liguori

>Regards,
>
>Christopher
>
>
>On 4/13/05, Anthony Liguori <aliguori@us.ibm.com> wrote:
>  
>
>>Ian Pratt wrote:
>>
>>    
>>
>>>OK, that's news to us - we haven't seen any problems.
>>>
>>>It's been tested with dd's and kernel builds, and wasn't expected to be
>>>a particularly dangerous change.
>>>
>>>How you confirmed that disabling the option fixes your problems? Can you
>>>give a simple recipe to provoke problems?
>>>
>>>      
>>>
>>We've had three different systems lose the ability to start domUs.
>>Disabling VBD grant tables fixed the problem.  The best reproducable
>>example we have is default config on a domU from today's xen-unstable
>>snapshot.  /dev/console is not accessible and no valid root is found.
>>
>>In my own case, it was working fairly well and then it just stopped
>>working.  It would die mid-way through boot.  Again, disabling VBD
>>grant-tables fixed the problem.  I'm going to look into the problem this
>>evening and see if I can get you guys a more reproducable scenario.
>>
>>    
>>
>>>It doesn't seem to be destablizing, at least for us. Possibly there's
>>>been some feature interaction with later checkins.
>>>
>>>
>>>      
>>>
>>Possibly.
>>
>>    
>>
>>>Anyone using the unstable tree should be reading the changelog
>>>closely...
>>>
>>>
>>>      
>>>
>>I agree.  I do, but I don't think a lot of people do.  I'm not trying to
>>give you guys more work to do :-)  Just a quick note to xen-devel would
>>suffice (if you've got an extra second).
>>
>>Thanks Ian,
>>
>>Regards,
>>Anthony Liguori
>>
>>    
>>
>>>Ian
>>>
>>>
>>>
>>>      
>>>
>>_______________________________________________
>>Xen-devel mailing list
>>Xen-devel@lists.xensource.com
>>http://lists.xensource.com/xen-devel
>>
>>    
>>
>
>  
>