[SOLVED] GRUB error 17, possibly due to damage in swap partition

[the dsc]

GRUB is not loading any menu; it just ends with the "error 17".

I can edit it through a live knoppix, all the "normal" partitions are fine, I can access them.

However, the swap partition is not recognized by gparted (says it's unknown); fdisk -l says

FATAL ERROR: Bad primary partition 3: Partition ends before sector 0



I don't know what to do. Can I just format the swap partition with gparted without losing the current linux installation? (well, if this is the solution, of course)




The output of fdisk -l, as it will probably be asked:

Disk /dev/hda: 40.0 GB, 40020664320 bytes
16 heads, 63 sectors/track, 77545 cylinders
Units = cylinders of 1008 * 512 = 516096 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hda1               1        9690     4883728+  93  Amoeba
Partition 1 does not end on cylinder boundary.
/dev/hda2           74556       77536     1502077+  15  Unknown
Partition 2 does not end on cylinder boundary.
/dev/hda3            9691       74556    32692275   93  Amoeba
Partition 3 does not end on cylinder boundary.
/dev/hda4               1           1           0   10  OPUS
Partition 4 does not end on cylinder boundary.

Partition table entries are not in disk order

hda1 - linux instalation

hda2 AND hda4 - linux swap (for some reason (actually, more likely without any reason besides newbieness) I had the swap partition inside a FAT32 of the same size

hda3 - /home


Gparted does not see that there are two partitions (hda2 and hda4 are seen as one, unreconized format)






A short summary of what lead possibly to that, perhaps someone with more expertise can spot something that is important, but it could have nothing to do with it:

I had windows installed, but it was "seeing" the linux partitons, which I find particularly scary, since it does not recognize the format and asks if we want to format them.

I've learnt that I should use the comand "hide" on the GRUB's menu.lst, but I don't quite know the syntax, so it may have started there. I've just set insert a "hide" command line referring to the whole linux HD, and went to test. It did work once, but when I rebooted the error 17 started.

I tried many possible alternative syntaxes, combining "hide" commands for the windows option with "unhide" for linux, as I thought it may be needed to "undo" the hide of the previous boot. After many attempts, I decided to just reinstall GRUB, and then I noticed the problem with the swap partition.

[MikeTbob]

You could just Fire up Knoppix, Delete the offending partitions and create a new Swap, then edit /etc/fstab accordingly.
Why are your partitions listed as Amoeba and OPUS?

[the dsc]

You could just Fire up Knoppix, Delete the offending partitions and create a new Swap, then edit /etc/fstab accordingly.

Thanks. I'm gonna do that then. I was worried that somehow the current instalation would require the current swap for some reason.

Why are your partitions listed as Amoeba and OPUS?

I have no idea.... I thought it was supposed to be that way... gparted recognizes hda1 and hda3 as ext3, anyway...

[the dsc]

Is it normal that partitions don't "end on cylinder boundary"? It does not sound like anything good.

[MikeTbob]

Is it normal that partitions don't "end on cylinder boundary"? It does not sound like anything good.

I don't know if it's normal or not, but I doubt that it's the cause of your problem, I have seen it before with no apparent effects.

[the dsc]

I've formatted the swap. Now I have a normal partition, not an "envelope" partition with another.

I've edited the fstab, but I still have "error 17" on grub, either on actual boot and when running grub and entering the command "root (hd0,0)" and/or "root (hd0)".

I think that this partition may be slightly damaged then.

Perhaps that would explain why it's being recognized as "amoeba" and the other one was "opus" (by the way, this topic is already the first result in google for these words, what an honor).

Would fsck.ext3 -f be reasonably safe? Or maybe I'm again missing the real point?

[the dsc]

Well... after searching a bit I didn't found nothing much scary about the command, but it didn't solved anyway, if the problem is this misrecognition (if that is really a word) of the partition type...

I'm reading in some places about cfisk.... I know that I can theoretically go and actually tell it to write in the partition table the correct partition type.... I thought it would format as well... but apparently it's a separate process...

[Type]With this option you can MARK any partition as a certain format type. THIS DOES NOT FORMAT THE PARTITION!! That is a seperate process to be completed later AFTER writing your partition table AND confirming the re-read of your partition table which may involve a reboot.

from [knoppix.net]Partitioning and cfdisk how-to and how to ungoof your MBR

... I'll read a bit more about it in more places before doing anything, anyway... the messages on cfdisk are so scary that it may even give me some nightmares... I'll wake up screaming "nooo! Don't format it! Don't!", soaked in my own sweat...

[devils casper]

I would suggest you to try GParted or PartedMagic LiveCD for managing partitions.

Is it normal that partitions don't "end on cylinder boundary"? It does not sound like anything good.

Yeah, its normal.

[the dsc]

The problem is that gparted at least does not have the function I suspect I need... as it recognizes the partiton correctly already. With cfdisk I think maybe I can rewrite just the partition table without formatting, so it would be recognized by GRUB as ext3 again.... I think I'll try only with the system partition, as the /home isn't required to be acessed by GRUB. If anything happens, I'll have to reinstall anyway, but the /home will probably be safe all the time. Compiling the kernel isn't so much of a trouble anyway.

[the dsc]

Great. Cfdisk does not the have "ext3" option. :/