Re: extended partitions

Theodore Ts'o (tytso@mit.edu)
Mon, 2 Oct 1995 14:35:18 -0400


Date: Mon, 2 Oct 1995 10:35:34 +0100
From: Andries.Brouwer@cwi.nl

: If we really want to do allow it, we could just set the size of the raw
: extended partition to be 2 sectors (1 block), and mke2fs won't be able
: to make a partition on a partition that small.

No, because only 1 sector is guaranteed to be free. Writing a
block to /dev/hda4 might destroy the first sector of /dev/hda5.

True, but destroying the first sector of /dev/hda5 should be easy to
recover from. That won't make a difference at all for the ext2
filesystem (unless there's a boot sector at that location, at which
point lilo will restore it), and for a DOS filesystem, Norton Utilities
shouldn't have any problems recovering from a smashed boot sector,
either.

Yes, this is a bit of an ugly kluge, but in general the first 512 bytes
of most filesystem formats are generally recoverable without losing any
real user data. And mke2fs will refuse to touch a partition that small
anyway, so the most common way someone might accidentally use /dev/hda4
will still be prevented.

- Ted