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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Tue May 24, 2011 1:58 am 
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Quote:
Alternatively you could do your backups with a program that automatically generates hashes such as duplicity. If you're not doing backups, you have bigger worries than hash management!

If I'm not doing backups, maybe hash checking-management maybe my only consolation though...


Still a lot to learn about computers and the internet...thanks for the info...


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Sat Jun 18, 2011 11:53 pm 
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HFat wrote:
What ddrescue does is to image the drive. It can be really slow if the drive has issues because it does not fail when it encounters a problem, it retries trouble spots and so on. As far as simple, free tools go, this is the one who'll give you the best image so far as I know. In some cases, you'll even get a perfect image.

You can then try whatever software you fancy to recover your files from the image. If you make a backup copy of the image first or if you keep the software from writing to it, you can mess things up and try again many times without doing any further damage to the failing drive.


Hi there, sorry to bother you again
it's been a long time, but I just now brought myself to getting on with recovering the data from the drive that had the most trouble.

I used a windows program first to attempt and salvage the data (same way, creating an image first) but the program (R-Drive) does not seem to be that efficient.

So I returned to ddrescue (I was discouraged a bit at first, some instructions I had found were not working too well for me) using a Parted Magic CD.

With advice from this pageand this page I used the following syntax:
Code:
ddrescue -f -n /dev/sdb5 /dev/sda5 rescue.log

Up to now - it has been running close to 7-8 hours, it has rescued 700gb out of the 2TB WD20EARS drive, which contained 1.3TB of actual data, if I remember correctly, and it has recorded two errors, concerning 18817kB of data (ipos)

After this command first rescues data in non-trouble areas, I will use a command of this sort (again drawing advice from the previous two links)
Code:
ddrescue -d -f -r* /dev/sdb5 /dev/sda5 rescue.log (*= the amount of read attempts)


I have some questions though, if you could help:

1) I fear it might have been a mistake not to specify the hard disc as a whole, e.g. sdb instead of sdb5 (in each device - source/destination - I get two IDs, 5=extended and 7=NTFS). I don't know why I did this exactly...I guess because "mount-gtk" in PartedMagic showed only the sda/b5 part (linux ignorant)...
Is this wrong?

2) Are the above commands correct?

3) How many read retries should I specify?

4) Do I need to run the following command after the above have finished?
Code:
e2fsck -v -f /dev/hdb2


5) Is there anything else I'm missing?


Cheers


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Sun Jun 19, 2011 2:04 am 
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Posts: 1694
Location: Switzerland
Pierre wrote:
1) I fear it might have been a mistake not to specify the hard disc as a whole, e.g. sdb instead of sdb5 (in each device - source/destination - I get two IDs, 5=extended and 7=NTFS).
Is this wrong?

Not wrong: it's maybe not ideal. It depends on what you want to do with the image. But there are many things you can do with just the partition.

I've never done what you've done with an extended partition and you didn't give any details on your drives and procedures but you might want to make sure your regular and extended parition tables are identical. I guess if you copy sd_5 it copies the parition record for sd_7 as well as the extended partitions but I don't know. And I don't know how NTFS would handle a situation where there was a mismatch between the partition record and the actual partition. It should be clever enough to deal with that but, again, I don't know.

I'd have imaged to a file instead of a drive or partition by the way: much simpler and the result is more versatile too (thanks to VM software).

Pierre wrote:
3) How many read retries should I specify?

Your call: 3 is probably what I'd use but if you don't have a lot of errors and want to make really sure you've done the best possible job you could try a higher value.

Pierre wrote:
4) Do I need to run the following command after the above have finished?
Code:
e2fsck -v -f /dev/hdb2

No. That's like chkdsk in Windows. Maybe you have an fsck for NTFS on the system you're using for dd. I think there are NTFS-specific utilities that could possibly be used to repair a partition which come with ntfs-3g and ntfstools. If you have some of these tools you could use that instead of e2fsck... but not so fast!
I don't know what you're doing and what your resources are but, ideally, you don't want to do anything to your image. What I'd do is to back it up first if possible or to isolate it from modifications through software (VM software is neat for that). With that approach, you can try any unproven software or harebrained approach you fancy and simply start over if it doesn't work without having to disturb the bad drive again.
But if you feel confident you're not going to damage the image or that you could recreate it if needed, go ahead and try to mount and/or repair your image without precautions. In that case think through what you're doing however! Maybe you want to use Windows. Who else than Microsoft knows how the various version of NTFS really work after all? I'm not saying that non-Microsoft tools couldn't succeed where Microsoft's fail (we've seen that before). But it would seem safer to try the official Microsoft way first, don't you think?

If the damage didn't affect the file system structure, you should be able to see and recover most of your files (not the ones affected by unrecoverable errors of course) easily as soon as dd_rescue has finished.
But if there's file system damage it could be more complicated. Depending on the data you're looking for, you could recover it from the raw partition without bothering with the file system. There are tools which do that but you can also do it manually (again, depending). Otherwise you'll have to try to repair the FS and that can be trouble... or not depending on the damage and the tools you're using. If both Windows as well as non-Microsoft NTFS implementations fail to mount your recovered partition because critical parts of the FS have been damaged and you're lost, best ask someplace where you'll find people who are knowldgable about recovering from NTFS breakage. The people documenting ddrescue or giving advice about it may not be the most qualified!


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Sun Jun 19, 2011 4:20 am 
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Quote:
Not wrong: it's maybe not ideal. It depends on what you want to do with the image. But there are many things you can do with just the partition.

I've never done what you've done with an extended partition and you didn't give any details on your drives and procedures but you might want to make sure your regular and extended parition tables are identical. I guess if you copy sd_5 it copies the parition record for sd_7 as well as the extended partitions but I don't know. And I don't know how NTFS would handle a situation where there was a mismatch between the partition record and the actual partition. It should be clever enough to deal with that but, again, I don't know.

I'd have imaged to a file instead of a drive or partition by the way: much simpler and the result is more versatile too (thanks to VM software).

Well, to tell you the truth I was kind of confused.
I found instructions for dd_rescue for outputting an image file, but in the ddrescue manual there were none, so I went on with what I had at hand.

This meaning, there was nothing out of the above discussed, that I wanted to do: Restore files, check, if possible, which ones have not been salvaged and save them to my regular data drive.

One (well, another) foolish thing I could have done is that I've used the drive that had produced a specific number of bad sectors (data copied from it to a replacement drive already) but is now stabilised - have stress tested it a bit - to save the data from the failing drive (since two drives would be needed, according to what we had discussed previously). I did that because because getting an RMA from the shop might take some time, and because then I would be able to copy the final set of rescued data to their final destination, the second new replacement drive

Quote:
Your call: 3 is probably what I'd use but if you don't have a lot of errors and want to make really sure you've done the best possible job you could try a higher value.

Well, I don't have much experience, but aren't 3 just too few? I don't know that the time-cost effect would be setting retries to 6-7, but I would -unknowingly- take that as minimal.

About the errors, you mean bad sectors? There must be over a thousand there.
Right now, with the parameters ddrescue is running, it has come across two of them.

Quote:
No. That's like chkdsk in Windows. Maybe you have an fsck for NTFS on the system you're using for dd. I think there are NTFS-specific utilities that could possibly be used to repair a partition which come with ntfs-3g and ntfstools. If you have some of these tools you could use that instead of e2fsck... but not so fast!
I don't know what you're doing and what your resources are but, ideally, you don't want to do anything to your image. What I'd do is to back it up first if possible or to isolate it from modifications through software (VM software is neat for that). With that approach, you can try any unproven software or harebrained approach you fancy and simply start over if it doesn't work without having to disturb the bad drive again.
But if you feel confident you're not going to damage the image or that you could recreate it if needed, go ahead and try to mount and/or repair your image without precautions. In that case think through what you're doing however! Maybe you want to use Windows. Who else than Microsoft knows how the various version of NTFS really work after all? I'm not saying that non-Microsoft tools couldn't succeed where Microsoft's fail (we've seen that before). But it would seem safer to try the official Microsoft way first, don't you think?

If the damage didn't affect the file system structure, you should be able to see and recover most of your files (not the ones affected by unrecoverable errors of course) easily as soon as dd_rescue has finished.
But if there's file system damage it could be more complicated. Depending on the data you're looking for, you could recover it from the raw partition without bothering with the file system. There are tools which do that but you can also do it manually (again, depending). Otherwise you'll have to try to repair the FS and that can be trouble... or not depending on the damage and the tools you're using. If both Windows as well as non-Microsoft NTFS implementations fail to mount your recovered partition because critical parts of the FS have been damaged and you're lost, best ask someplace where you'll find people who are knowldgable about recovering from NTFS breakage. The people documenting ddrescue or giving advice about it may not be the most qualified!

Yes, file structure damage could be another issue.

What do you mean by the "Microsoft way", exactly? The check disk utility?
There are many utilities out for repairing file structure, I don't know how effectively though.
From what I read around people might also use the "test disk" utility or other software that focus on recovering data from damaged partitions (instead of actually repairing them)
So, since I won't actually be keeping the drive that I use for restoration, maybe I could afford not to dwell too much on file system repair? Of course I don't know what is worse, trying to fix the file structure or restoring files from damaged file structure.
But that may not be the case after all ..(?)..

You are right, the creation of an image file would have made thing much simpler
- What is the appropriate command for that?

Since the bad drive can fail at any time, I don't know if I will have the opportunity to retry ddrescue to save an image file.


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Sun Jun 19, 2011 5:21 am 
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Pierre wrote:
I found instructions for dd_rescue for outputting an image file, but in the ddrescue manual there were none, so I went on with what I had at hand.

This meaning, there was nothing out of the above discussed, that I wanted to do: Restore files, check, if possible, which ones have not been salvaged and save them to my regular data drive.

The ddrescue manual's first example outputs an image file (hdimage). That is not the same as restoring files. It simply means copying the drive's data to a very large file which can then be manipulated (compressed to save space, fingerprinted and so on) by any program.

The manual also explains a trick to mark bad files from a recovered partition irrespective of the file system involved. But most of the operations you talk about are FS-dependant and therefore outside the scope of ddrescue.
If the drive isn't too badly broken and ddrescue is able to do good job, there'll be nothing special to do after ddrescue has finished recovering the data from the bad drive (just access the imaged drive like a regular drive, assuming the partition table is valid).

Pierre wrote:
One (well, another) foolish thing I could have done is that I've used the drive that had produced a specific number of bad sectors (data copied from it to a replacement drive already) but is now stabilised - have stress tested it a bit - to save the data from the failing drive

If it passed your stress-testing, you'll probably be alright.
It's not the safest thing but I don't throw away drives as soon as they get a few bad sectors. Most of them can still serve for years as backup drives and so forth (if you go by the "at least three copies" rule, it's OK if some of them are on somewhat dubious drives).

Pierre wrote:
Well, I don't have much experience, but aren't 3 just too few? I don't know that the time-cost effect would be setting retries to 6-7, but I would -unknowingly- take that as minimal.

About the errors, you mean bad sectors? There must be over a thousand there.
Right now, with the parameters ddrescue is running, it has come across two of them.

Well, I'm pessimistic. If it doesn't work after three attempts...
But you have only two errors with about 19MB to retry, right? It shouldn't take ages to retry these aeras many times so go ahead with your optimistic (or desperate?) settings.

Pierre wrote:
What do you mean by the "Microsoft way", exactly? The check disk utility?

Whatever Microsoft recommends (they probably have some KB article about this). That would certainly include chkdsk but maybe they recommend something else in addition in case the drive has gone bad. I've never needed anything else except when the data was overwritten or the drive was totally shot (that's beyond the help of any software). So if you could run chkdsk without affecting your image or on a copy of the image, I'd simply try chkdsk. But if you have only one shot at this, maybe you should check out Microsoft's documentation first.

Pierre wrote:
From what I read around people might also use the "test disk" utility or other software that focus on recovering data from damaged partitions (instead of actually repairing them)

Yeah, that's what I called "recovering [your data] from the raw partition". I think ddrescue's manual mentions such a tool: photorec

I've never used Testdisk but it sounds like it can do more than just that and tries to package several capabilities in a user-friendly way. It may have done the ddrescue operation (or equivalent) for you.

Pieer wrote:
So, since I won't actually be keeping the drive that I use for restoration, maybe I could afford not to dwell too much on file system repair? Of course I don't know what is worse, trying to fix the file structure or restoring files from damaged file structure.

It doesn't matter is you're going to keep the drive or not. What matters is:
-do you know what files you want to recover? can these files be identified? if not, you'll need to fix the file system
-how many files do you want to recover? if there are many, it might be simpler to try to fix the file system
-do you care about recovering files names and location (as opposed to the contents alone)? if yes, you'd better try to fix the filesystem
Files can be identified most easily in the raw partition with plain text strings they might contain or because they have some other kind of marker such as magic numbers (only useful if you don't have too many files of the same type). Check out photorec and get some idea of what it can and can't do.


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Sun Jun 19, 2011 7:13 am 
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Quote:
The ddrescue manual's first example outputs an image file (hdimage). That is not the same as restoring files. It simply means copying the drive's data to a very large file which can then be manipulated (compressed to save space, fingerprinted and so on) by any program.

The manual also explains a trick to mark bad files from a recovered partition irrespective of the file system involved. But most of the operations you talk about are FS-dependant and therefore outside the scope of ddrescue.
If the drive isn't too badly broken and ddrescue is able to do good job, there'll be nothing special to do after ddrescue has finished recovering the data from the bad drive (just access the imaged drive like a regular drive, assuming the partition table is valid).


Oops...that's what one gets for reading manuals 3-4 hours after midnight in hot weather with his eyes barely open...I kinda missed it the reference to the imagefile. It was the parameters that caught my eye in that example...
I will read the manual more cautiously to get rid of the confusion...

Quote:
Well, I'm pessimistic. If it doesn't work after three attempts...
But you have only two errors with about 19MB to retry, right? It shouldn't take ages to retry these aeras many times so go ahead with your optimistic (or desperate?) settings.

This is strange to me however, because if the damage was so small, the absolute inability to boot into windows with this drive and even mount it on linux, would be difficult to explain...linux's smart check showed about 1000 bad sectors...
So it may have to do also with the way data is accessed with the ddrescue command?

When running Drive-Image,which ran a hell lot slower than ddrescue, I pressed retry on 3 occasions and got no result...ddrescue seems to be doing a far better job throughout with regard to speed and efficiency, so I'll give it a go with 6 retries.

Quote:
-do you know what files you want to recover? can these files be identified? if not, you'll need to fix the file system

The vast majority of files are photo and video files, maybe a lot of text files too (mostly subs, i.e. largely unimportant) and a few .pdf files.
I know the types of files, I don't have so many specific files I can remember separately that I want to save
Quote:
-do you know what files you want to recover? can these files be identified? if not, you'll need to fix the file system

Oh,they're many, many in number...
Quote:
-do you care about recovering files names and location (as opposed to the contents alone)? if yes, you'd better try to fix the filesystem

It would be some waste of time reorganizing them, but it's not like I must have their particular folder placement, or hell will break loose. Easier, not absolutely necessary
Quote:
Files can be identified most easily in the raw partition with plain text strings they might contain or because they have some other kind of marker such as magic numbers (only useful if you don't have too many files of the same type). Check out photorec and get some idea of what it can and can't do.

If the drive is bootable into windows but file structure is messed up, I also hear File Scavenger is very very effective for NTFS volumes. Will also check Photorescue...


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Sun Jun 19, 2011 7:51 am 
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It sounds like you've got enough of a mess to make it worthwhile to try all you can to repair the file system if it's broken. Rescuing the files one by one would be a major PITA (it can't be fully automated).

Pierre wrote:
This is strange to me however, because if the damage was so small, the absolute inability to boot into windows with this drive and even mount it on linux, would be difficult to explain...linux's smart check showed about 1000 bad sectors...

1000 bad sectors would only be 500K (or 4M with 4K sectors). You've apparently got more bad sectors than just those.

I wouldn't be concerned by an inability to boot into Windows with the drive (and I wouldn't try to boot the imaged drive: boot another drive with this one as a secondary).
But if it couldn't mount on Linux, it might be bad... or not so bad. ddrescue isn't magic but copying the good data to a drive which doesn't stall unpredictably when you try to read from it could make a world of difference even if some data is missing.


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Mon Jun 20, 2011 10:40 am 
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The second test for the trouble areas is now officially running for as much time as it took to rescue the 2TBs of data.....this even if, after running the test for 3-4 hours with 6 retries, I interrupted the test to change the parameter to 3 retries...
...while I had that parameter set to 6 retries, I got a successful read every 30min or so...after changing to 3 retries it's been more than 18 hours since the last successful read..not sure if this means I should increase it to get better results...

The error size fell from 18817kB to 13787kB before the first run had finished.
After running the second command the error size fell to 13774kB, while the retries were set to 6. These past 18 hours have not had any further effect.


Supposing that I end up with a this error size. Is there a way to find out which files these 13MB concern?
It could belong to a single video file, to a series of small image files etc...
Is there a way to determine that?

Cheers


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Mon Jun 20, 2011 11:54 am 
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Pierre wrote:
while I had that parameter set to 6 retries, I got a successful read every 30min or so...after changing to 3 retries it's been more than 18 hours since the last successful read..not sure if this means I should increase it to get better results...

You shouldn't interrupt it to change the number of retries. Unless the feature has been added recently, it doesn't handle that gracefully.
My guess is that you've hit a troublespot or that the drive's condition has deteriorated. If that troublespot was already there before today and it contains a part of the file system data, you can see why it wouldn't mount!

If you're in a hurry, you could give up on some of the lost data and use an offset to tell ddrescue to only try the end of the drive. I've never done it but there should be an option for that. But be very careful with the advanced options if you're writing to your only good copy of the data!

Pierre wrote:
Supposing that I end up with a this error size. Is there a way to find out which files these 13MB concern?
It could belong to a single video file, to a series of small image files etc...
Is there a way to determine that?

I very much doubt a single file is affected. It could also affect the file system data, deleted data, or simply unused capacity.

The manual explains some ways to determine that. There are more. One of the ways assume the rescued copy can be mounted without affecting its content (please refer to my earlier comments about VM software and so on).
If you can not backup your rescued copy, be careful with these tricks (please refer blah blah).

Unless you're in a hurry, let ddrescue finish first.
But if the drive has died or simply locked-up somehow (requiring a power cycle), it may never finish so exercise some common sense...


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Mon Jun 20, 2011 1:31 pm 
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Quote:
You shouldn't interrupt it to change the number of retries. Unless the feature has been added recently, it doesn't handle that gracefully.

I did not stop the program by force, e.g. shutting down...it displays "Press Control-C to interrupt" at the beginning of each running test.

My first thought was that more retries are indeed necessary. As you suggested there are other alternatives, that I have hit a troublespot, or that the program didn't handle the interruption gracefully, or that the drive has somehow been affected.
Since it has not stopped responding, though, normally it should just proceed to the next sector...
It's just that right now I don't know if it is doing anything.

Normally, since I can save the logfile, I can reboot and restart, right?


I was getting a little tired, so I interrupted the test, and booted into windows. Before logging in, I got a prompt to check the file system of the drive I saved the data to for errors. At that point I didn't...
I booted into windows and then went to "My Computer".
The drive didn't show up properly there, it displayed just the drive letter...after a while the system started locking up for a few seconds, so I shut it down.

Damn I'm tired of this and I am tiring you too.


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Mon Jun 20, 2011 2:01 pm 
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Pierre wrote:
I was getting a little tired, so I interrupted the test, and booted into windows. Before logging in, I got a prompt to check the file system of the drive I saved the data to for errors. At that point I didn't...
I booted into windows and then went to "My Computer".
The drive didn't show up properly there, it displayed just the drive letter...after a while the system started locking up for a few seconds, so I shut it down.

Since you may have written to your target already, you might as well forget about resuming ddrescue.

I don't understand the system locking up... did you boot the partially-recovered drive? I hope not.
Unless your target drive is also going bad, it seems you've got a broken filesystem. How badly, we don't know.

If you don't want to learn the proper procedure from Microsoft, you should try chkdsk (which, for all I know, is the proper procedure anyway). Avoid writing to the drive (that means don't boot form it!) because you might want to try to recover data that the file system has lost with programs like photorec or the commercial one you mentionned. But if you write to it, you could overwrite more than the missing 14 MBs.


To the other people reading this: you think you can avoid such ordeals with RAID, LVM, ZFS or some other scheme? Think again! RAID is great (it saved my butt before so I'm not complaining) but a RAM error or a bug can take out your file system and a lot of data in spite of perfectly working drives. It happened to me with NTFS. Backups are paramount!


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Mon Jun 20, 2011 2:55 pm 
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Thank you for your swift answer, patience and for sticking with me on this...and I know I haven't been helpful or quick picking it up...
I'm somewhere between trying to get some work done, doing bothersome errands for the family and protesting the new fiscal austerity measures/memorandum in the streets of Greece...when I finally get down to this technical issue, I am fatigued, I have a headache and I can barely follow instructions either...
This damn lcd screen of my old, old laptop is also not helpful...besides the bad display quality, 1024x768 resolution now officially sucks...
(sorry for that, not in the greatest of moods and can't help complaining)


I am considering attempting to get a data image file from the failing drive to my newest hdd, just in case the other thing goes wrong and the first drive dies on me...

I didn't try to boot the drive. I started getting the lockups after I opened an hdd monitor program to check the drive's smart details...
But it's probably the bad filesystem you mentioned...


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Mon Jun 20, 2011 3:05 pm 
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No need to apologize. Many of us have been in a situation with non-cooperating hardware and software. It's annoying enough when your backups are in order. That and trying to hit the streets while working or passing exams... so good night and good luck!


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Mon Jun 20, 2011 3:31 pm 
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Thanks for the support HFat

I can't seem to get ddrescue to create an image file in my other hdd...is there something wrong with this command?
Code:
ddrescue -n /dev/sda /dev/sdb5/backup/backup.img /media/sdc1/rescue.log

I get the following error:
-"Can't open output file: Not a directory"
even if I throw the -f command in there, it doesn't make any difference. I created a folder "backup" in my hdd because it didn't like the /dev/sdb5/backup.img either...

Do I also have to create the "backup.img" file too?


EDIT:

I gave up on the above and I tried to boot into windows, having connected the drive I had saved data to, it notified me it would check it for consistency before booting into the OS.I got the message
Quote:
Corrupt master file table, Windows will attempt to recover master file table from disk.

and so it's just sitting there, I don't know if it is actually doing anything (win7 Ult. x64)...


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Tue Jun 21, 2011 3:10 am 
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Having heard nothing from you today, I don't know if you've solved the problems below by now. Just in case:

Pierre wrote:
I can't seem to get ddrescue to create an image file in my other hdd...is there something wrong with this command?
Code:
ddrescue -n /dev/sda /dev/sdb5/backup/backup.img /media/sdc1/rescue.log

I get the following error:
-"Can't open output file: Not a directory"

The /dev/sd_ paths are for direct access to drives. They're not like the drive letters in Windows (in Windows, you can access a drive which has no letter). If you want to access a file, you need to go through the file system. In order to do so, you must mount the file system, as you'd do in Windows. Windows tends to do this automatically, as do desktop versions of most operating systems. But maintenance tools tend to require you to it manually so that nothing is touched without your explicit consent.
So issue commands like:
mkdir /targetdrive
mount /dev/sdb7 /targetdrive
ddrescue -n /dev/sda /targetdrive/imagefile /targetdrive/rescue.log
This assumes your environment has the software to mount NTFS. You may need to specify NTFS as a mount option (I don't remember if it can be recognized automatically). You may also need to specify the read-write mount option (sometimes the defaults are set to read-only for safety).

If you launch a new ddrescue run, think about what you'll do next while it's working. In particular, think about using VM software to access the image file non-destructively in the future (and collect the software and information necessary to do so).

Pierre wrote:
Quote:
Corrupt master file table, Windows will attempt to recover master file table from disk.

and so it's just sitting there, I don't know if it is actually doing anything (win7 Ult. x64)...

If that didn't work, you can try running chkdisk manually with the appropriate options. You can try consulting Microsoft's documentation or asking Windows/NTFS gurus. You can try fixing the file-system with non-Microsoft tools such as the testdisk you mentionned or the ones which probably come with ntfs-3g (use a recent version, some Live CDs probably have it). There are Windows-based tools which may be better at fixing NTFS.
You may also want to give something like photorec (or the file recovery capabilites of testdisk or ...) a try, first as a sanity check (did ddrescue actually work or did the drive return garabage when ddrescue read from it?) and also to give you a feel of what it'd be like to try to recover your data without fixing NTFS.
In any case there's a number of things you can try before giving up on that rescued parition. And what you learned can be then applied to another copy. So I recommend working on it a bit before running ddrescue again, preferrably with the advice of some people who are knowledgable about fixing NTFS.
Unless you have destroyed the backup MFT by accessing the partition without repairing it first as Windows suggested or you do a better ddrescue (which may not be possible), the problem won't be fixed simply by running ddrescue again.


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Wed Jun 22, 2011 10:07 pm 
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Joined: Sun Jan 17, 2010 3:55 am
Posts: 127
Location: Greece
Quote:
If that didn't work, you can try running chkdisk manually with the appropriate options. You can try consulting Microsoft's documentation or asking Windows/NTFS gurus. You can try fixing the file-system with non-Microsoft tools such as the testdisk you mentionned or the ones which probably come with ntfs-3g (use a recent version, some Live CDs probably have it). There are Windows-based tools which may be better at fixing NTFS.
You may also want to give something like photorec (or the file recovery capabilites of testdisk or ...) a try, first as a sanity check (did ddrescue actually work or did the drive return garabage when ddrescue read from it?) and also to give you a feel of what it'd be like to try to recover your data without fixing NTFS.
In any case there's a number of things you can try before giving up on that rescued parition. And what you learned can be then applied to another copy. So I recommend working on it a bit before running ddrescue again, preferrably with the advice of some people who are knowledgable about fixing NTFS.
Unless you have destroyed the backup MFT by accessing the partition without repairing it first as Windows suggested or you do a better ddrescue (which may not be possible), the problem won't be fixed simply by running ddrescue again.

I Have Conquered the Beast!! [__THIS___IS___{SPAR...} a little provincial town just a few kilometers south of * resting on the roots of mountain * (whatever) ] ....

I used a couple of programs I had mentioned earlier to scan the hard drive and see what they could attempt to restore from it, and I was very happy to see that File Scavenger both managed to recognize international file names correctly and discover the proper folder structure of those files, for the vast majority of them at least...
The scan took quite a while (10 hours approximately) to complete but it was very thorough...I tried another program, which read only a fraction of the files that File Scavenger discovered, so I gave that up...
Then I proceeded to the actual recovery process with File Scavenger...it copied 1.27TB in a little less than 5 hours...the program reports whether the recovery process is successful or not for every single file, but it does caution that even successfully recovered files need to be verified, so I spent all yesterday afternoon and evening testing as many files and file types I could to confirm they had been restored properly...
It seems all were indeed successfully recovered...the only bad ones were some of the files whose volume affiliation was not properly recognized (all bundled in an "Unknown" folder), but were in fact damaged and truncated copies of others files successfully recovered in some other folder...
It also came up with some audio files I am pretty sure I never owned...don't know where they came from...

To sum up,

HURRAY!!

I would like to thank you HFat for your continuous, patient and informative support and for proposing that miraculous little program, ddrescue, in the first place...it got me out of the mud...


Last edited by Pierre on Thu Jun 23, 2011 2:51 am, edited 1 time in total.

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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Thu Jun 23, 2011 12:32 am 
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Joined: Thu Jul 03, 2008 4:27 am
Posts: 1694
Location: Switzerland
Congratulations and thanks for letting us know that File Scavenger is a competent utility. This might be useful to some of us at some point.
You were lucky the drive didn't simply die, leaving you with nothing. So really, do some backups now! It's more convenient to backup to other drives of the same size of course but if you're on a budget you can back up the important stuff to a bunch of smaller drives people are throwing away (or to tapes or to DVDs or...).


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 Post subject: Re: Seagate Barracuda Green 2TB & Momentus 750GB
PostPosted: Thu Jun 23, 2011 2:50 am 
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Joined: Sun Jan 17, 2010 3:55 am
Posts: 127
Location: Greece
HFat wrote:
Congratulations and thanks for letting us know that File Scavenger is a competent utility. This might be useful to some of us at some point.
You were lucky the drive didn't simply die, leaving you with nothing. So really, do some backups now! It's more convenient to backup to other drives of the same size of course but if you're on a budget you can back up the important stuff to a bunch of smaller drives people are throwing away (or to tapes or to DVDs or...).

Yes you are right about that...
But saying I am currently on a budget is putting it very mildly, actually it's approximating euphemism...
So I can't afford to be safe, I am just left with being sorry...and a little lucky, as you said...

I bought the two new drives, to which I copied the data from the other two faulty ones, with the intent of selling the replacements of the latter ones as soon as possible...
They were new drives, just a few months old, so keeping them as backup feels like a "waste" at this moment (predicament)...but next time I need an upgrade, I'll probably keep the older drives, with a "best of" selection of files, including the really important ones...

Cause luck does run out...


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