Brian Kroth wrote: > Luis Freitas <lfreita...@yahoo.com> 2009-05-20 10:46: >> I am not aware of any filesystem that can withstand a online fsck. >> Sun ZFS can do online correction, but it doesnt have a fsck tool. > I hear btrfs will support this. It may be a feature that's easier to > accomplish with copy on write.
Yes. fsck in non-cow file systems scan the volume multiple times each time starting from a different point. Then it matches the collected data and looks for inconsistencies. Say it finds an inode but it is not in any directory. It will add it to lost+found. Or, that inode is not allocated in the appropriate bitmap. It will allocate it. etc. etc. For this to work, it needs the ondisk image to be frozen. If the volume is mounted, then it will have to lock out all nodes... which is effectively umount. Remember that the fs has journaling. The journal is replayed as part of node recovery and/or mount. So fsck is more an added security than anything else. _______________________________________________ Ocfs2-users mailing list Ocfs2-users@oss.oracle.com http://oss.oracle.com/mailman/listinfo/ocfs2-users
