On Friday April 7, osk@xxxxxxxxxxxxxxxxxxxxxxxx wrote: > Unfortunately md lacks the ability to mark an array as > used/busy/you_name_it. Sometime ago I asked on this list for such an > enhancement (see thread with subject "Question: array locking, > possible"). Although I managed (with great help from few people on > this list) to attract Neil's attention, I couldn't fine enough > arguments to convince him to put this topic on hist TO-DO list. > Neil, you see the constantly growing number of potential users of this > feature? ;-) I don't think that just marking an array "don't mount" is really a useful solution. And if it was, it would be something done in 'mdadm' rather than in 'md'. What you really want is cluster wide locking using DLM or similar. That way when the node which has active use of the array fails, another node can pick up automatically. Then we could put a flag in the superblock which says 'shared', and md would need a special request to assemble such an array. One thing that is on my todo list is supporting shared raid1, so that several nodes in the cluster can assemble the same raid1 and access it - providing that the clients all do proper mutual exclusion as e.g. OCFS does. Your desire to have only-assembled-once would be trivial to include in that. NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
