bad superblock

[Harry Kuhman]

OK, when Knoppix can't open an NTFS partition and reports instead a "bad superblock", what is it trying to tell me? Any fix, even for opening the NTFS partition in read-only so I can get any files off of it? XP just looks at the disk while booting, flashes something on the screen too fast to read, shuts down the computer, and then it powers up again and the cycle starts over again.

[Jevington]

Hi
I have the same problem did you ever solve this ?

[Harry Kuhman]

As you can see, I got no feedback and nothing that I could find to do in Knoppix would help. There may very well be things that Knoppix could have done, but I don't know what they would be.

I ended up using a lot of Windows tools to attack it and slowly nursed it back to life. At one point when it still would not boot I had it well enough that Knoppix could read the partition. At that point I did use Knoppix to copy everything that I wanted to save to another computer on the network. BUt I later managed to get the disk booting and didn't need this. Sorry but this was months ago and I didn't take notes on all the utilities that I threw at it or which ones that I think did what. I still have no understanding of the true nature of the problem, what is wrong when this is seen, and what it takes to fix it.

If you learn more, please post it back here. At least that way we'll both have a record of it for the next time XP does this to us, and I have little doubt that there will be a next time with XP.

I'm also not clear about what the testdisc is that you used if you are having the same problem, since I couldn't get into XP at all.

[ckamin]

OK, when Knoppix can't open an NTFS partition and reports instead a "bad superblock", what is it trying to tell me?
Check the following link to some information on exactly what a "Superblock" is supposed to be in Solaris UFS file system: http://docsun.cites.uiuc.edu/sun_docs/C/solaris_9/SUNWaadm/SYSADV1/p172.html#FSFILESYSAPPX-3 I will assume that it is the same application in Linux/Unix as Solaris UFS. I would venture a W.A.G that the error message is due to a corrupted file system in the NTFS partition. If it were a UFS partition, look here for the resolution: http://docsun.cites.uiuc.edu/sun_docs/C/solaris_9/SUNWaadm/SYSADV1/p169.html . The procedure may shed some light on what the error might mean. Unfortunately, you mentioned that it was an NTFS partition that Linux was complaining about. It then has to be something in the NTFS partition that is corrupted, since Win XP AND Linux are both complaining about it. I have not experienced the error message you mentioned while using Knoppix/Linux, but have had Disc errors in Windows that were similar to what you had described. The only tool I have ever used to fix something like this is the Recovery Console in XP. Just boot from the xp cd to the recovery console and type "FIXMBR". I believe that will replace the MBR with a backup copy on the disk. It worked a few times for me in the past. It is the equivalent of the MBR switch when using FDISK on a FAT or FAT32 partition from DOS. I am sure that there might be some other tool that could fix it and one that might be more appropriate. I just never bothered to look any further since my problems were fixed by using the recovery console. I am not aware of any tool that Knoppix has that can fix an NTFS partition error such as this, but I have only limited knowledge of using Linux tools on NTFS partitions. There could very wll be an appropriate tool on the Knoppix disc or even something like the Helix or Insert discs. I have avoided writing to or modifying an NTFS partition with anything other than Windows. It sometimes ends up as a disaster like the one you described and I won't even begin to tell you how I might know that. :wink:

[harken]

I don't know if you've seen this definition (http://www.bellevuelinux.org/superblock) of a superblock already but I thought I'd mention it. Also, I encountered this kind of problem after I used improperly the dd command, applying a zero-ing to the wrong partition. I got it back with succes with the help of TestDisk (http://www.cgsecurity.org/index.html?testdisk.html). It is a utility which can be ran under DOS, Windows and Linux. It will scan for your lost partitions (it has a "deeper scan" option, which will attempt to read the backup partition table), it will display them so you will have to write down the heads/cylinders/sectors charateristics of the ones you are interested in and this way you can add them back to the table.
It worked like a charm for me so I warmly recommend it.

[ckamin]

I don't know if you've seen this definition of a superblock already
That is a good description. I have seen much more detailed information on the superblock and it's format, content, etc. I just used that link since it was short, not too complex, and to the point. Most Unix type operating systems use the Superblock terminology. Windows has a similar function in it's file systems and when Unix/Linux encounters an error, it uses it's native terminology to describe the error. Hence the use of the term Superblock in reference to a Windows NTFS partition error.


I got it back with succes with the help of TestDisk. It is a utility which can be ran under DOS, Windows and Linux.
I have seen the Testdisk program, but I have not yet had an opportunity, or a need to use it. I found that the recovery console in Windows did what I needed it to do and I was much more familiar with it. Testdisk looks promising, but it is an unknown quantity for me and I will use what I have had experience and positive results with. I would try to work with it on a test system a little before I used it to recover something critical. I just liked the simplicity of the recovery console for Win XP for the easy solution I needed. One command did it all without the need to get into an overly involved process. I did not encounter a severely corrupted partition and TestDisk appears it may be more useful when things have gone from bad to worse. I have a collection of disk utilities that I have yet to need or try. I am also very hesitant to write to, or modify an NTFS partition with something other than Windows. I have learned a hard lesson about that more than once.

I have had very few instances where I could not recover the information that I needed and then just reload the OS and start over. I do back up most of the important stuff regularly. I usually get involved with partition/file recovery when it involves someone else's system. I have also had a few "Learning Experiences" about what you should NOT do to NTFS and other file systems. I have been lucky so far and I have had only a few hardware failures that could not be recovered. The one thing I have learned throughout all of it is that the need to back up critical information can not be overstated, especially BEFORE doing something that might cause a data loss.

Thanks for the additional information!

[harken]

I just liked the simplicity of the recovery console for Win XP for the easy solution I needed. One command did it all without the need to get into an overly involved process. I did not encounter a severely corrupted partition and TestDisk appears it may be more useful when things have gone from bad to worse.Indeed, the Recovery Console is simple in usage but also limited in functionality. I mean, of course a "fixmbr" and/or "fixboot" will restore a corrupted (by another bootloader) MBR, but that's pretty much all AFAIK. But think that the whole partition table is gone, just as it was in my case, you have nothing to restore with fixmbr. Actually, I ran
dd if=/dev/zero of/dev/hdaand only after a good 20-30 seconds I realized what I just typed. So, without any advertising intention, TestDisk actually scanned for lost partitions (I don't know if there's any tool in Rec. Console which can do that) and, more important, found them. But, while TestDisk's UI is not complicated at all, you must wait a few minutes until it finishes scanning and also write down some characteristics. Erm...and it's a little short on documentation.
Anyway, I found TD to be just what I needed, so I just thought I could let others know, maybe it'll help them too.

[ckamin]

Erm...and it's a little short on documentation.
Anyway, I found TD to be just what I needed, so I just thought I could let others know, maybe it'll help them too.
TestDisk appears to be a good program and one that may be a little too complex for the average user at first glance. I do intend to work with it on a test system sometime and take a better look at it. I would hesitate to try it on something that is mission critical without knowing a little more about how it works and what it can do. Not being familiar with something can be a dangerous situation, especially when the documentation is a little lacking. I'm sure that it will be a good choice for myself or someone else and will prove useful at that time, as it has for you. Help is what these forums are all about and I truly appreciate the efforts of others who freely spend the time and effort in those regards. I have learned a great deal just lurking and listening in over time. I have found many solutions to past, present, and probably future issues in this, and many other forums.

I just use whatever lame tools I can find within Windows to try and fix Windows first, unless I know of something that is better suited. If I could truly "Fix" Windows, I'd have one on B. Gates and company. Using something more complex and time consuming than that required is like killing a fly by dropping a house on it. I certainly don't want to imply that the Windows Recovery Console is the best tool and that it can do everything that there is to do. I just use it when it is appropriate. I am always looking at alternatives to Windows and tools that can fix things that I may not have even seen or heard of yet. It is that curiosity that got me to this forum and others. I now have a great collection of "Live Disks" and other useful tools that continues to grow.

I try to avoid those "OOPS" moments if I can and just try to keep a running backup of critical information. It may cost a bunch and take up a lot of room, but I have not been sorry that I do it. If I have a good backup, the "broken" drive gets blanked and reformatted to whatever filesystem it needs to be, or trashcanned and I don't need to spend the time fixing it to recover it's contents. I have had many of those "I can't believe I typed that" episodes. Knowing what you did wrong helps greatly when trying to recover from those self inflicted setbacks. If things didn't break or get broken, I would never really learn anything and life would be boring indeed!