Directory File Inode Structure

[Linwood Varney]

In article <5434 at ingr.com> igug at ingr.com (Igug Moderator) writes:
>Over a period of time I understand that a directory file will continue
>to grow as new inode slots are added.  When the files in a directory
>get deleted and the inode is nulled out, the size of the directory yet
>remains the same. Fine, now when I begin to add files again are the
>old slots, that were nulled, reused in the same sequence?

When a file is created, the first nulled out entry is used.

>Also, will I
>encounter 'file system indirection' only when I access a file that has
>its inode in the 321st slot?

What do you mean by file system indirection.  the first 64 directory entries
are stored in 1 logical block (1K) of data on the disk. the next 64 in another
and so on.  After 10 logical blocks are used, a file system indirect block
has to be read to get to the next 512 (1K) blocks.

This is the struct for System V 1K File Systems.  Fast File Systems look much
different.

>Also, can I look at a directory file with fsdb and can anyone recommend
>a good book that covers use of fsdb.

The easiest way to look at directories is with od -c
first 2 bytes, inode number, next 14 bytes, file name.  16 bytes per record.

	- linwood