grub error 21 boot problems

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silver-one

grub error 21 boot problems

Post by silver-one »

I have a problem I can't seem to fix.
I have been running Elyssa ever since it has come out. It runs great I love it.
Well today while surfing the net, my system locked up. Cold nothing worked not keyboard not mouse nothing.
So I rebooted the system by turning it off and back on.
When it went to load grub it gave me an error 18
So I booted to the live cd and downloaded super grub and installed it on a usb pen drive.
I rebooted into super grub.
I did a repair to the grub file and it completed without errors.
So I rebooted.
And now I get an grub error 21

If I boot to the live cd I can't open my hard drive. It is a sata drive.
I can see it if I fdisk -l, but I can't seem to mount it.

What can I do to get my information off of it if I can't fix it?

Thanks in advanced for the help
Ronnie
Last edited by LockBot on Wed Dec 28, 2022 7:16 am, edited 1 time in total.
Reason: Topic automatically closed 6 months after creation. New replies are no longer allowed.
Husse

Re: grub error 21 boot problems

Post by Husse »

Have you tried pmount?
man pmount
We really need to see what's in menu.lst (and fstab)
silver-one

Re: grub error 21 boot problems

Post by silver-one »

pmount is for a removable drive.
Mine is a regular sata drive, it's been working perfect.

I opened gparted and check and there is a warning symble next to my main linux boot partition. When I check infromation it says, e2label: Attempt to read block from filesystem resulted in short read while trying to open /dev/sdb1. Couldn't find valid filesystem super block.

I checked on the internet for superblocks and found a command that shows me backup superblocks on my drive.
mke2fs -n /dev/sdb1
so I ran this and found which superblocks I could use. After I ran.
e2fsck -b 32768 /dev/sdb1
but when I run this command it comes back with this error.
e2fsck: Device or resource busy while trying to open /dev/sdb1
Filesystem mounted or opened exclusively by another program?
I don't know what to do from here?????

Please Help.
Ronnie
silver-one

Re: grub error 21 boot problems

Post by silver-one »

Well it seems that I won't be able to fix the hard drive.

Does anyone know a simple way to salvage the information off of a hard drive that you cant mount???


Thanks
Ronnie
Husse

Re: grub error 21 boot problems

Post by Husse »

First off - if you suspect errors of a basic kind be very careful
Try to mount it in another computer or another operating system
If that fails too I'm afraid you have to resort to a data salvage company
There are many now - you don't have to use the large and expensive ones
wight

Re: grub error 21 boot problems

Post by wight »

Its been a couple of days but if you're still trying to get past the drive mounted exclusivley error you might try to use another live cd to rescue the partition. I have had good success using puppy linux in cases like these. One of the particular advantages is that puppy does not mount any disk when booting from the cd.
silver-one

Re: grub error 21 boot problems

Post by silver-one »

Some times I just can't understand things?

Anyway. Yes I am still trying to recover my data.
I've checked around and many people say use testdisk and photorec.
When I used testdisk 6.9 it will show me all the files on my hard drive, just as if they were all there just like they should be.
But I can't seem to fix the disk to get to the files.

So now I am trying photorec. My problems is that photorec will recover some of my files, (maybe, it's still working), but it dosen't recover all types of files. For instance my thunderbird directory with all my emails, that I can't afford to loose. photorec dosen't help me there.

Wish there was something a little better to get these files.

I've pulled the drive and have it hooked up via USB, I can see it via fdisk -l, just can't mount it.

Well will see if photorec is worth much.

Anyone with other ideas I'm game.
I live in a small country out side of the U.S. and they don't have data recovery shops.
So I'll have to struggle until my drive gives it's last spin and is sent to were all dead drives go. :twisted:

Ron
Husse

Re: grub error 21 boot problems

Post by Husse »

I think this could be, or rather is, a logical error and if that's true I can help make it useable again, but that would mean loosing all data
But you are on the right track - hook it up to another system and save what you can
This was your system disk?
I reread your first post
So I rebooted the system by turning it off and back on.
So you rebooted with the power button?
That can cause logical damage (hardly physical damage)
The way to proceed is to press AltGr and SysRq at the same time and then key in REISUB and you get a safe reboot
Too late now ....
wight

Re: grub error 21 boot problems

Post by wight »

I have found testdisk useful in recovering deleted partitions but not so much if you want to rescue files. Photorec only looks for certain files types to recover and does not retain directory structures. In fact I have not been able to find any Opensource recovery tools that can recover entire directory structures. Anyone know of any? I only know of some recovery utils for windows partitions that can do that... maybe some of them work for linux but none of them wark for recovering deleted files on ext3 partitions. To my knowledge this can't be done. This kind of sucks I thought linux ext3 was supposed to be the way to go so now I have hundreds of gigabytes of data committed to ext3 partitions and no easy way to change this. I suppose, in the linux world, they figure users are more backup conscious and so have not come up with the tools yet for those scenarios where a backup may not exist (or be possible).

If anyone knows of any free or opensource tools that can recover files and retain entire directory structures from windows and/or linux partitions please post some suggestions.

Anyway back to your problem silver-one... Have you been able to get past the drive mounted exclusively problem? If not, then crossing that hurdle just might yield the solution to your problem. I have been multibooting systems with several linux distros and windows and mounting ext3 drives as ext2 under windows using the IFS Driver. In all my tinkering I have had several partitions come up with errors that prevented me from mounting them. Particularly on my USB backup drive. so far, knock on wood, I have been able to fix them everytime using e2fsck from my puppy linux boot cd. I haven't even had to run e2fsck with any special instructions either. I highly recommend you go this route before doing anything further.

Another utility you might want to look at is ddrescue (not to be confused with dd_rescue). I have used it to recover from scratched cds and dvds. I'm not sure if it will help in your situation, however, if you've got errors which will prevent it from identifying the boundaries of the partition.
silver-one

Re: grub error 21 boot problems

Post by silver-one »

Well photorec was a wast of time, both for me and my limited life hard drive. It took 6hrs and returned mostly info that I can't use.

Husse, on the reboot. Not one key on my keyboard worked when my system crashed. The only way I could reboot was the power button.

I have tried several rescue cds. Rescue CD for Linux and Ubuntu Rescue CD.
These are great but I can't seem to be able to repair the superblock error. I can't mount the hard drive even if I want to.

In all, with testdisk I can see my hole system perfect, just can't copy it to a new drive.
Photorec can recover files, if you have the patients to sift through the results and find anything usefull.

Is there a program on windows that might be able to save my data on a ext3. I could even manage that. As I have a windows system here.

Well anyway, loosing hope rapidly.
:(
Rone
wight

Re: grub error 21 boot problems

Post by wight »

silver-one, both the original error 18 and error 21 appear to be BIOS related. I would be very careful about running any repairs on the file system if bios is not seeing the drive properly. if all you've done thus far is repair grub then the problem is likely that the bios settings are wrong and grub can;t be read from the designated partition (since it can't be mounted) e2fsck should not be run in this state. That you got the drive mounted exclusively error that prevented you from running it is probably a good thing.

There was a thread I came across that recommended setting the drive to LBA and Auto in CMOS. This seemed to work for several people with a grub error 21 problem. You may still have file system errors due to the improper shutdown for which a boot cd like puppy linux, as I recommended before, and e2fsck may be the answer.

Just how important your data is and whether you have the resources available (another system to put the drive in enough room to hold a full recovery, etc) will play a big factor in how big a risk you can take trying to recover your data. Google minipe, a live XP cd with a ton of recovery and maintenance utilities, and see if any of the data recovery tools will work for linux partitions. (worth a try) I don't know about the legality of using such a tool where you are from tho which is why I hesitate to mention it. I prefer to try to stick with open source and free tools where possible. If minipe isn't a possibilty, and you have the room, use ddrescue to try to backup the partition and see if the ddrescue image can be mounted. (not likely, I would think) keep in mind however that ddrescue will get the entire partition and not just the data so if its a 200GB parttion this may not be possible. You can also try to get the whole drive, if it is a small drive and you have room for it, just to back it up before doing any attempted repairs to the file system. I don't really know if the backup will be able to be restored to the drive if BIOS isn't seeing the drive properly tho since I'm no expert. but if you have the room for the backup its better to have it than not.

Maybe someone else who knows more about file systems can give us some info on the usefulness of a dd image from a drive that is being improperly reported in BIOS or has superblock errors?
Husse

Re: grub error 21 boot problems

Post by Husse »

wight you are right
A tool that can do a sector by sector copy makes the data safe - after that one can experiment freely with the disk
I don't know if ddrescue can do the trick here but commercial software like Acronis and ghost can
Wight

Re: grub error 21 boot problems

Post by Wight »

Husse,

My question is whether or not a sector by sector copy can be useful if the drive is misreported in BIOS. DD and DDrescue can definitely do the job if the drive parameters are known.
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Mordak
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Re: grub error 21 boot problems

Post by Mordak »

FWIW, I have had success recovering data from bad/damaged drives with Spinrite (Google spinrite). It's not free but you can download an ISO image and burn it to a CD and boot to it. It runs on FreeDOS and reads the drive at the most basic level below even OS' and BIOS. It's easiest to put the drive in a PC that you can leave running the programs for up several days in some cases. If there is physical damage to the drive as in the read write head impacted the drive platter while spinning or if the laptop was dropped during a read/write operation then it could take some time. I once ran it on a drive for over 1 week and was able to recover all the data but the drive was toast and not trustworthy enough to keep using. However, no data loss. Good luck.
Ken
silver-one

Re: grub error 21 boot problems

Post by silver-one »

I connected the drive to a windows xp computer with acronis, this also saw the drive and showed my partitions. Showed where my data was. But couldn't mount the drive.

It seems that part of my problem is this. The drive is a 250gb drive. I don't have another 250gb or better drive.

Most of the fixes that seem like they could work need a drive of the same size or bigger.
Which I understand, but I only have 60gb of data on the hole drive. There doesn't seem to be a program that can only grab the data. I have another drive that has 80gb of free space where I could copy all this data. But ddrescue, acronis or another program I have checked wants to make a drive copy sector by sector.

I haven't given up yet, even if I have to wait awhile till I can go out and get another drive. I'll find a way to get the data off.
Thanks for all the Ideas and advice, I'll just keep working at it.

Ron
Husse

Re: grub error 21 boot problems

Post by Husse »

I have Acronis (workstation - the almost only reason I keep XP)
You can choose to compress the tib file it writes and it should fit on a 80 GB disk
I have you on a list of disk problems, that's why I gave you the link to the new wiki - that's not your problem
Husse

Re: grub error 21 boot problems

Post by Husse »

I've read this again and I don't have much valuable to say
Spinrite is good
http://www.grc.com/sr/spinrite.htm
dd_rescue also seems interesting (Note - this is not the same as ddrescue, both can rescue data though)
Fred

Re: grub error 21 boot problems

Post by Fred »

silver-one,

I was just skimming through your thread. I was left with a couple questions.

Did you try using Puppy linux to see if you could mount the partition with puppy or run fsck on the drive partition in question? If you can you are home free.

Just a note. If you can see the partition, it is mounted. Maybe not properly, but it is mounted. If you can see the folder tree, it is mounted and you can copy it.

You can probably construct an rsync command to pick out the files/folders you want to save.

Just a couple thoughts.

Fred

PS: This is going to sound silly, but did you know that if you put a failing drive in the fridge for a while it will sometimes come back to life long enough to strip the data off it?
Husse

Re: grub error 21 boot problems

Post by Husse »

Oh yes - even the freezer - but let it thaw for a day at least
And I'm not joking
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