>Although, it is not possible with the current code, it should be possible >to do via failing the branches. First, you fail the branch intended for >backups and it becomes a backup copy. Later you can "unfail" the same >branch and fail the newer branch to start the on-line recovery. If you >enable atime updates on these lower file systems incremental (delta) >updates should not be a problem. So I guess you're saying that what you have now doesn't have the ability to recover from a temporary absence of a member by updating just the areas that changed while it was absent. Given how complex the path to one of these member filesystems might be, and how big a filesystem can be, I would think that's pretty important for making RAIF practical. Actually getting to the cloneset-like thing is a step further, though, because it doesn't have the instantaneous resync property -- if you fail a branch while it's being resynced, you can't then access that branch and expect to get current data. But I didn't actually understand, "Later you can 'unfail' the same branch and fail the newer branch to start the on-line recovery," so maybe you're talking about something different. I would think that if you fail the only branch that has current data on it (the "newer branch"?) that recovery would be pretty much over. -- Bryan Henderson IBM Almaden Research Center San Jose CA Filesystems - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
