> From: Richard Elling [mailto:richard.ell...@gmail.com] > Sent: Sunday, April 25, 2010 2:12 PM > > > E did exist. Inode 12345 existed, but it had a different name at the > time > > OK, I'll believe you. > > How about this? > > mv a/E/c a/c > mv a/E a/c > mv a/c a/E
The thing that's still confusing you is the idea that directory names or locations matter. They don't. Remember that a directory is just an inode, with text and data inside it, which stores an association of child names and child inode numbers. Suppose "somedir" is inode 12345. Then if you "ls somedir/.snapshot/somesnap" then the system is reading a version of inode 12345 in a time gone by. At that time, inode 12345 may have been referenced by its parent using the name "foo" instead of "somedir" but that won't even matter in this case because we've only instructed the system to read the contents of a past version of inode 12345. In this case, we haven't told the system to do anything even slightly related to any parent of that inode. We're not even going to know what name was associated with inode 12345 at that time. At the time of somesnap, inode 12345 had contents which indicate "a.txt" is inode 1000 and "b.txt" is inode 1050 and so on. So "a.txt" and "b.txt" will appear in the directory listing, and if you cat a.txt or b.txt, the system will fetch inode 1000 or 1050 as it appeared at the time of the snapshot. Does that help? There is no actual entity called ".snapshot" It's a magical thing, just like there is no actual entity called ".zfs" If you "ls somedir" or "ls somezfsfilesystem" you will see, that the parent inode does not contain any reference to anything called ".snapshot" or ".zfs" (Unless you turned it on for some reason.) However, if you "cd .snapshot" or "cd .zfs" then there's some magic behind the scenes that's able to handle that differently. I don't know how they do that. But I do know it's not listed in the inode like any other normal child subdirectory or file. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
