[sheepdog] data corruption under cache enabled node

[Hitoshi Mitake]

At Fri, 07 Feb 2014 15:10:31 +0900,
tuji wrote:
> 
> Hi
> 
> I got corruption on my vm under enabled cache function.
> And I have reproduce the problem by dog command.
> 
> The vm was moved by live migration. so I believe 
> same data corruption was happen for my vm.
> 
> node002 and node003 are with cache. 
> sheep -p 7000 /home/sheepdog,/home/sheepdog/obj1,/home/sheepdog/obj2 -w size=30000,directio,dir=/home/sheepdog > /dev/null 2>&1
> 
> node001 and node004 are with out cache sheepdog. 
> sheep -p 7000 /home/sheepdog,/home/sheepdog/obj1,/home/sheepdog/obj2  > /dev/null 2>&1
> 
> Sheepdog version is 0.7.6
> 
> [root at node001 ~]# ssh node001 dog vdi create sheeptest 1024
> [root at node001 ~]# ssh node001 "echo aaaa |dog vdi write sheeptest"
> [root at node001 ~]# ssh node001 dog vdi read sheeptest
> aaaa
> [root at node001 ~]# ssh node002 dog vdi read sheeptest
> aaaa
> [root at node001 ~]# ssh node003 dog vdi read sheeptest
> aaaa
> [root at node001 ~]# ssh node004 dog vdi read sheeptest
> aaaa
> [root at node001 ~]# ssh node002 "echo 1234 |dog vdi write sheeptest"
> [root at node001 ~]# ssh node001 dog vdi read sheeptest
> 1234
> [root at node001 ~]# ssh node002 dog vdi read sheeptest
> 1234
> [root at node001 ~]# ssh node003 dog vdi read sheeptest
> aaaa
> [root at node001 ~]# ssh node004 dog vdi read sheeptest
> 1234
> 
> The data was not updated for node003 after new data was written.
> 
> And I found corruption is solved by "dog vdi cache delete".
> 
> [root at node001 ~]# ssh node002 dog vdi cache flush sheeptest
> [root at node001 ~]# ssh node001 dog vdi read sheeptest
> 1234
> [root at node001 ~]# ssh node002 dog vdi read sheeptest
> 1234
> [root at node001 ~]# ssh node003 dog vdi read sheeptest
> aaaa
> [root at node001 ~]# ssh node004 dog vdi read sheeptest
> 1234
> [root at node001 ~]# ssh node002 dog vdi cache delete sheeptest
> [root at node001 ~]# ssh node001 dog vdi read sheeptest
> 1234
> [root at node001 ~]# ssh node002 dog vdi read sheeptest
> 1234
> [root at node001 ~]# ssh node003 dog vdi read sheeptest
> 1234
> [root at node001 ~]# ssh node004 dog vdi read sheeptest
> 1234

Hi,

Thanks a lot for your report and a way to reproduce. I'd like to work on the bug
ASAP. If you have time, could you add an issue on our launchpad tracker?

https://launchpad.net/sheepdog-project

Thanks,
Hitoshi