OK. I have two hard drives, one parallel ATA with Slackware, one SATA with Windows XP. Using lilo to dual boot. I have spent the last three days solidly configuring my Slackware system. It is (was???) perfect.

Let me tell you the story of what just happened to me.

I wrote an entry for Windows in /etc/lilo.conf. I ran lilo. I restarted my computer. I tried to boot into Windows, and, I can't remember the error, but it wouldn't load. But I figured out quite quickly that it was because I'd told lilo to load a partition, instead of the whole disk.

So I rebooted again, and Lilo came up, and I went into Slackware. I edited /etc/lilo.conf to change "/dev/sda1" to "/dev/sda", ran lilo, and rebooted. I left the room for a minute, and got ready to go to bed, having spent literally 12 hours perfecting my installation and achieved everything I wanted to do with it. It was 4.30am and I was feeling quite pleased.

I came back to my computer, assuming that by now Slackware would have loaded because I'd been gone more than 5 minutes.

"Missing OS," the screen said.

"What?" I said.

"Missing OS," it said.

Now, every time I try to boot to my Linux hard drive, I get "Missing OS". Windows is fine. I've had a panic attack about this. If I have lost my hard drive, my life will be over. Everything in my world is on that hard drive and I don't have a backup of most of it.

I've tried a couple of things. I've unplugged the other drive, but got the same error. I've put the drive in a different computer - exactly the same error. I've used a live disk - dyne:bolic, one that came free with a magazine, and I don't know it very well. Apparently my hard drive partitions should have been mounted in /vol, but that directory was empty.

I found my Slackware boot disk and am too scared to boot it and run cfdisk to see what partitions are there.

What I want to know, before I do that, is, what do you think happened? Hard drive failure? Could it be that my partition tables got corrupted somehow? I know that it's not that my lilo.conf is wrong - the lilo bootloader is never even reached. It just goes straight to "Missing OS". What can I do to salvage all my data??

Please give me hope.

Just try booting with you Slackware CD ( There is a line, waht you have to type to boot a previously installed Slackware from hdd -something like boot bare.i /dev/hda1 noinitrd ro guess you should use boot sata.s .... since you have a sata Harddrive )

After boot ing your installed Slackware login as root and type liloconf. Thats the confirguration utility for lilo from setup.
Choose expert and start building a new lilo.conf.
Trust me, Slackwrae will know what to do, I also have a dual boot system ( though I only have pata hdds )

Good luck

Thank you...

While yours is a very good idea... I really don't think it's going to work:

I took the Linux (PATA) hard drive and put it into my other computer which had no other hard drives in it. I booted Slackware off the install disk. I ran cfdisk. Apparently the partitions on my Linux drive are now 197G NTFS, 3G FAT32. There were 6 partitions on there before. The partition table matches exactly that of the Windows drive. And yes, I definitely didn't put the other drive in, because that one's SATA and screwed into the other case.

My root partition *was* hda3. But apparently hda3 doesn't exist anymore. :/

I can't work out for the life of me why my partition table would have been changed!! *tears out hair*

If I plug both drives into one computer and boot the Windows one, Windows hangs during boot (in the blue loading screen). It's fine without the Linux drive involved. I guess it must be trying to find the partitions that aren't really there.

Is it safe to run cfdisk and just repartition it to exactly what it was before? I don't trust myself with this, eurgh.

I'm not much of an expert on this, but which drive do you have as master and which as slave? If the XP drive is currently set as slave, whilst the linux drive is master, that might explain why you can't boot the XP drive with the linux drive plugged in simultaneously? Try swapping them over and seeing what effect that has...

just a thought...?

PS You have a very nice writing style

Any chance you had Raid 1 turned on? From what your seeing on the disk I had to wonder if it started (but did not finish) mirroring your other drive.

There are companies that can recover data off of crashed disks. The harder it is to get at the data, the more they charge though.

Since it appears to have changed the drive to ntfs can you mount it as a slave in another system and see if any of the files are readable?

Good luck!

There are many misunderstandings in your post. Changing bootloaders or screwing up a lilo.conf (which is almost certainly a part of this problem) do not affect filesystems. You need to run fdisk -l so we can see what your partition tables look like. Don't be scared, the -l option runs read only and exits before you can do anything bad.

You should cut and paste that, and your lilo.conf, and then we'll have some facts. Anything else is just guessing and wasting time.

Okay. Thank you all for your ideas and comments

Randux: Maybe I'm not expressing myself properly, but I'm not misunderstanding. Please forgive my original post for being full of ambiguities - I wrote it at 5 in the morning, while I was having somewhat of a panic attack about all of this! I'm rather more coherent now..

When I used cfdisk this morning (from a Slack live CD) to look at the partitions on my Linux drive, it told me that I had a FAT32 partition and an NTFS partition exactly the same as my other drive. I know that bootloaders and lilo.conf and rebooting won't change my partition table, but somehow it happened. I can't for the life of me work out how. I'm just going to assume that it was when I was booting into Windows (I don't trust Windows not to screw things up without telling me).

How it happened isn't the point. I've progressed a little further since my last post.

I got someone (advertised in the paper..) to come and have a look at it, and he ran a program called testdisk off a CD, which scanned my disk and found all my *real* partitions. The table we were shown matched the table I wrote down when I made all the partitions a few months ago. We rewrote my partition table so it's correct now.

When I went back into the Slack Live CD, I was able to mount the drive at last, and discovered that all my data is intact! (*HAPPY DANCE*)

BUT when I ran cfdisk I was given an error - can't remember it verbatim, but it told me that partition 3 goes off the end of the disk. Partition 3 is my root partition, and is not near the end of the disk. There is an extended partition after it, containing 2 more partitions.

I am still getting the Missing OS error on bootup.

Going under now; I'll remove any mention of Windows from lilo.conf and see what happens.

I'm in Slackware! It worked! So the booting problem was lilo's fault. The weird other problem of partition table rewriting still remains a mystery.

But everything is back to normal now.

Second time that I've posted a problem on these forums and then solved it by myself

EDITED TO ADD:

"cfdisk /dev/hda" gives

But since it's all otherwise usable, it's alright.

EDITED AGAIN TO ADD:

I reckon my boot sector just got totally screwed over, losing my partition table AND my MBR. Which is really strange, but it all fits together now, and is sorted