@cks

Which in turn then prompts the question of whether one with suitable chicanery could set it up as a correct i-node which fsck would consider allocated, but that would be unfixable.

Presumably the reference counting checks would detect it as an an orphan, but putting a directory entry referencing it in lost+found would not work.

Assuming that the reference counting pass does not also have a < ROOTINO short-circuit in the code too. (-:

#Unix #filesystems #FFS #UFS #FreeBSD

@cks

The same thought occurred to me. There have been cute tricks like that played. I've even played some of them on other systems.

But as far as I know that first entry in the i-node table was just unused.

I wonder whether fsck even checked it. Modern FreeBSD fsck_ffs does, but that's a very different beast.

#Unix #filesystems #FFS #UFS

@cks

Off By One Error in your post on this. (-:

Since 0 means a free directory entry, that's only 65535 i-nodes.

Mind you, at 8 i-nodes per block, you'd come close to the size of some contemporary discs with a maximally sized i-node table.

#Unix #filesystems

@spacehobo @brouhaha

Yes. Berkeley FFS broke things up into cylinder groups and had an allocation policy of putting various things in the same CG and other things not, because much the same idea was also useful for reducing seeks on discs.

(Even OS/2 got in on the act. (-: Its FAT filesytem driver put the extended attributes record for every file in front of the file data where it could. Which was why it was a bad idea to defragment the "EA DATA. SF" file so that it ended up stuffed all at the start of the volume.)

And the elevator algorithm in the block cache would at least make the tape do straight runs in one direction and then rewind, where it could.

Putting filesystem *and* swap on tape boggles the mind, though. (-:

#Unix #magtape #filesystems #tar #DEC #retrocomputing

@atoponce

There seem to be no answers matching "back". Both options match "up".

I think that you've overlooked an even more important poll that might be the shibboleth of our time: Does one go up and down a tree? Or does one go back and forth a tree?

Has the tree been chopped down?

(-:

#shell #POSIX #filesystems