Thanks for the reply.
Well, actually, "sfdisk" simply creates the tables this way. Admittedly, most people don't use sfdisk either but normal fdisk or cfdisk does the same with respect to the layout. Those do insist on cylinder alignment more (ie, the head of the chain of logicals wouldn't generally live in the second sector) but the point here really is that installing GRUB should never ever overwrite more than the first sector since it's never guaranteed to be available for use.
Second, don't get me wrong, I agree that directly reporting to the GRUB folks would be helpful but here it's definitely relevant as well. I mean, really, no matter what else, installing Zenwalk 6.2 BETA on a dedicated testing partition had the effect of destroying everything on the disk and that's a pretty serious bug to report. The point of beta's is getting bugs reported...
I'm here from several years of basically using my own distribution, also on a slackware base, and mostly because I started lacking the time and inclination to deal with all the problems directly myself. Generally, users of a distribution are expected to report problems to the distribution after which the distribution filters the noise and relays that which is applicable upstream. Yeah, I understand that Zenwalk might be a bit small and non-professional (in a financial sense) to have that be as true as it would be for the bigger distributions, but hey, it's the idea of things...
You do seem to know what you're talking about with respect to "the gap" so let me assure you that yes, there really wasn't one. Here's my partition layout:
Code: Select all
Device Boot Start End #sectors Id System
/dev/sda1 1 692272486 692272486 85 Linux extended
/dev/sda2 692272487 976773167 284500681 7 HPFS/NTFS
/dev/sda3 0 - 0 0 Empty
/dev/sda4 0 - 0 0 Empty
/dev/sda5 2 16777217 16777216 83 Linux
/dev/sda6 16777219 33554434 16777216 83 Linux
/dev/sda7 33554436 50331651 16777216 83 Linux
/dev/sda8 50331653 67108868 16777216 83 Linux
/dev/sda9 67108870 379690677 312581808 83 Linux
/dev/sda10 379690679 692272486 312581808 83 Linux
The tables therefore live in sector 0 (MBR), 1 (first sector of the extended), 16777218 and so on. What happened is that not just sector 0 but also sector 1 got overwritten while installing 6.2 BETA. After figuring out what the problem was (I of course had a dead system at that point) I could manually restore sector 1 but really only because I also knew that my /dev/sda5 was exactly 16777216 sectors in size. Had that not been the case, I wouldn't have known to pick up the chain at sector 16777218. That is, definitely more luck than anything else that I was able to patch things back again.
Finally, do please note that my attitude is definitely not
that new things are bad. My attitude is that new things that destroy my computer are bad. I love most other new things...
I will contact the GRUB developers. I expect they'll just boot me back here though since they'll assume (as you do) that they never make assumptions about MBR length. They seem to do though, and do so as a bug...