Ok, I just had the same issue - or at least a similar one. Unfortunately the box has some other problems and I don't have network with me.
It affected a RAID0 as well and I'm running 2.6.36. I was rebooting into 2.6.38 and after that reboot my RAID array was gone. I have to admit that array has a partially faulty disk (hence me working on it).
The symptom was that /proc/mdstat reported an inactive device md4 in state (S). The other physical devices participating in this array did not show up in /proc/mdstat. When trying to --assemble /dev/md4 it would complain that the one physical device listed in the incomplete md4 was reported "in use". The event counters were equal on all four participating partitions and the "partner" partitions were properly listed, i.e. `mdadm --examine /dev/sd{a,b,c,d}4` spit out all correct information. I'm in the process of downsizing this RAID0 (hence the kernel upgrade). This device had seen a `mdadm --grow --array-size` before and a `mdadm --grow --size` was attempted, but failed in the past. More details can be found in my "log" here: http://miriup.de/index.php?option=com_content&view=article&id=83:wading-through-my-own-raid-and-lvm-mess&catid=8:linux&Itemid=25&lang=en
I did `mdadm --stop /dev/md4` followed by `mdadm --assemble /dev/md4` which fixed the problem.
Ok, I just had the same issue - or at least a similar one. Unfortunately the box has some other problems and I don't have network with me.
It affected a RAID0 as well and I'm running 2.6.36. I was rebooting into 2.6.38 and after that reboot my RAID array was gone. I have to admit that array has a partially faulty disk (hence me working on it).
The symptom was that /proc/mdstat reported an inactive device md4 in state (S). The other physical devices participating in this array did not show up in /proc/mdstat. When trying to --assemble /dev/md4 it would complain that the one physical device listed in the incomplete md4 was reported "in use". The event counters were equal on all four participating partitions and the "partner" partitions were properly listed, i.e. `mdadm --examine /dev/sd{a,b,c,d}4` spit out all correct information. I'm in the process of downsizing this RAID0 (hence the kernel upgrade). This device had seen a `mdadm --grow --array-size` before and a `mdadm --grow --size` was attempted, but failed in the past. More details can be found in my "log" here: http:// miriup. de/index. php?option= com_content& view=article& id=83:wading- through- my-own- raid-and- lvm-mess& catid=8: linux&Itemid= 25&lang= en
I did `mdadm --stop /dev/md4` followed by `mdadm --assemble /dev/md4` which fixed the problem.