Erling Nygaard <nygaard@xxxxxxxxxx> writes: > No, this will not work at all. > > All GFS locking is done on a filesystem level. In order to make this work > you need locking on the blocksystem level . I guess I'm looking for a concrete reason why it won't work. I've been assuming it won't work, but I can't think of a concrete reason. You need to lock a resource group to allocate blocks for a file, and you need to lock the file in order to modify its blocks, so it's not entirely clear to me why you need block-level locking when md is involved. The only concrete problem I can think of is that the md has a superblock, and no node would know that other nodes are using the same md superblock. -- Ed L Cashin <ecashin@xxxxxxxxxx>
