On Wednesday November 20, brugolsky@telemetry-investments.com wrote: > On Wed, Nov 20, 2002 at 03:09:18PM +1100, Neil Brown wrote: > > u32 feature_map /* bit map of extra features in superblock */ > > Perhaps compat/incompat feature flags, like ext[23]? I thought about that, but am not sure that it makes sense as there is much less metadata in a raid array than there is in a filesystem. I think I am happier to have initial code require feature_map == 0 or it doesn't get loaded, and if it becomes an issue, get user-space to clear any 'compatible' flags before passing the device to an 'old' kernel. > > Also, journal information, such as a journal UUID? As there is no current code, or serious project that I know of, to add journalling to md (I have thought about it, but it isn't a priority) I wouldn't like to pre-empt it at all by defining fields now. I would rather that presense-of-a-journal be indicated by a bit in the feature map, and that would imply uuid was stored in one of the current 'pad' fields. I think there is plenty of space. Thanks, NeilBrown > > Regards, > > Bill Rugolsky - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
