On Aug 01, 2007 11:46 +0530, Aneesh Kumar K.V wrote: > Andreas Dilger wrote: > >On Aug 01, 2007 07:34 +0530, Aneesh Kumar K.V wrote: > >>undoe2fs can be used to replay the transaction saved > >>in the transaction file using undo I/O Manager > > > >This should save the mtime of the superblock, and only do the undo > >step if the filesystem hasn't changed. Otherwise it could seriously > >corrupt the filesystem. > > I am not sure i understand this. The Undo I/O manager tracks all the write > happening to the file system and copy the original content of the blocks to > the tdb file. Undoe2fs simply copies these blocks back to the file system. > > That way if you look at undoe2fs it doesn't have any knowledge of the file > system at all. > > Can you let me know a use case where this will fail. - modify filesystem with undo manager (e.g. inode resize) - mount filesystem, make changes, unmount - run undoe2fs to overwrite filesystem, corrupting it Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc. - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
