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Data Recovery


G-Stress
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Okay guys, I'm close to pulling my hair out now lol.

Recently I had a drive fail on my which was entirely encrypted via truecrypt, as soon as I noticed it started to fail I went and bought a new drive and got things up and running again. I've tried a few vendor's to recover the data and have had best success with EaseUS Data Recovery. It finds quite a bit of data, but in raw format I guess. It just now tonight dawned on me that I'm betting because I encrypted the entire disk with truecrypt is why I cannot read/play any of the files.

So I installed truecrypt regular installation in hopes to decrypt the disk, but when I Select Device, Volume Tools, Permanently Decrypt I goto enter the password and it always returns invalid password or not a truecrypt volume.

I have tried a few other software to scan the disk for files, but nothing has found as much data as EaseUS. Is there something better? The weird thing is, this drive isn't doing the "click of death", but when recovery software is scanning the disk occasionally it will "click".

It shows the 100MB system partition in my computer and the 465GB partition and when you try to explore either it says it needs to be formatted. I'm using an EZ Dock USB to read the disk to backup data. Hoping there is a solution to retrieve the data.

Thanks in advance!

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The click is something like a reset of sorts for the harddisk. When it's repetitive is when you should really worry.

I don't quite get what you're saying. You pay a company good money to recover data off a disk, claim they're fairly succesful, and then seem to suggest you're trying your own luck reading back the data from your original disk?

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No I did not pay a company. I'm trying to recover the data myself. I have installed EaseUS Data Recovery and a few others to recover the data. EaseUS has found most of the data compared to the other software's I've tried. However a video file for example won't play and I think it might be due to the fact I encrypted the entire disk with truecrypt.

I guess right now I'm trying to decrypt the disk with truecrypt then attempt to recover the data, but when I try to decrypt the data with truecrypt it always returns wrong password or not a truecrypt volume.

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Thanks for the quick and prompt replies guys. I was actually able to recover my data. After running a few software's wondering why I couldn't access the data it recovered it dawned on me (oh yea it's an encrypted disk)

Using an EZ-Dock I was able to mount the disk "without pre-boot authentication" and then I was able to open my computer, access the drive and grab the data. I have since switched to Bitlocker.

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Very much dependent on your specific situation. I always thought I needed RAID5 but as time progressed I fell back onto a small RAID1 for the truly important stuff and the rest JBOD. It just made more sense for me financially, performance-wise and even simply with the amount of space a big RAID takes up.

If you do go with RAID, please go for software RAID. It might perform slightly less, but the alternative binds your array to the controller chip of your RAID card (since it decides how to distribute the file parts across the array) which, to me at least, sounds like a very bad situation.

Do note that any form of RAID doesn't equal backup. If you accidentally remove a file, it's gone no matter how many disks originally contained the file.

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Which RAID to use is normally dictated by a combination of how many disks you can justify using in the array and how resilient from a disk failure perspective you want it to be.

If you want some resilience and only have room for 2 disks then the only option is RAID 1.

If on the other hand you have 3 disks then you can use RAID 5 and have an array that would survive a single disk failure, or RAID 1 with the data mirrored across all 3 disks (assuming your setup supports RAID 1 on more than 2 disks).

If you have 4 or more disks available for the array then you could look to using RAID 6, which will survive up to 2 concurrent disk failures.

Personally I would go with RAID 1 unless there is a need for more space than a single drive can provide, in which case I would be looking to RAID 6.

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I'm familiar with raid, but never have set one up. I have this raid array now at home with 13x300GB SCSI disks, but it's old. The connection is LVD and I've never messed with any of that. I would like to be able to use these disks.

For my personal raid I am thinking of grabbing a couple 6TB or 8TB drives and doing a raid 1 or raid 5. I'll look into raid 6. Or possibly a drobo.

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The problem with old disks:

- They die sooner than new drives (duh).

- They use more power, meaning they're more expensive to run and the heat needs to be expelled some way aswell if you want to have any hope of a decent lifespan.

- They are generally slower than modern drives.

My biggest problem with my 10 disk RAID5 array was that I wasn't around to make use of it 50% of the time, so I would allow the disks to spin down to conserve power and reduce heat. The consequence of this was that when I got home and tried to access any one file all those harddisks had to spin up again, which could take upwards of 20 seconds.

In my opinion, you want RAID generally because you want/need the added performance and/or want/need the added reliability. When you have a RAID5 array, you require the provided redundancy to counteract increased chance of a drive dieing on you (since there are simply more disks in a position to die on you, the chance of any 1 doing so increases). So in general you take RAID5 when you want a disk bigger than what you can feasibly buy in the store or you want the added throughput it can provide. RAID6 I think was RAID5 with a hot spare, so more redundancy at the cost of capacity (the space of 2 drives lost as opposed to just 1 drive).

The questions you should ask yourself is why do you want a RAID array, how much are you willing to spend on it and are you going to use it sufficiently to warrant that investment. And, as I noted before, since RAID isn't a replacement for a good backup, how are you going to create a backup of all that data? If you're only going to back up a part of it, why even put that part in the array? Why not just create an array for the parts that you also want to back up? That's the stage where I am now. I've got a 1TB RAID1 for photographs and the sort. The unchanging stuff gets backed up onto DVD and stored in a safe at my parents'. The remaining volatile bits I back up roughly once per week using an external HD.

I'm currently using 3 disks totalling 6 TB (2x2TB as a 1TB RAID1 and the remainder as plain storage plus a 3TB disk) and I've begun culling the data on there, seriously asking myself how important that file is to me. "How likely is it that I want to see this movie (again)?" "How important is it for me to have this file available to me instantly as opposed to having to wait, say, half an hour for a download to complete?" "What's the chance that I will want to (base future) work on this very old document?" By doing this I've halved the stuff I've got stored already and I'm still going strong. I genuinely expect to be able to take out the 3TB disk and maybe even drop the 2 disks and just plonk everything on the 3TB one, feeling sufficiently confident that my backup strategy renders the RAID1 obsolete...

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The other Cooper's right about the problems with old disks, though I would also add that they are usually much smaller to the list (13X300GB is about the same space as a modern 4TB disk).

Note: RAID 5 with a hot spare and RAID 6 are different. RAID5 with a hot spare leaves one disk unused and if any of the other disks in the array fail it will rebuild the array using that spare disk. RAID 6 uses all the disk but stores twice as much parity information on them so that the array can be rebuilt even it two disks fail at the same time.

Personally the real worry for me whenever I've used RAID 5 (with or without a hot spare) is that rebuilding a RAID array puts more stress on the disks than usual, and a degraded RAID 5 array can't afford to loose another disk in the rebuild.

These days the only reason to use RAID 5 and a hot spare would be if your system didn't support RAID 6. There are arguments that RAID 5 and a hot spare has better performance in some situations, but if performance is your key requirement then you wouldn't be looking at RAID 5 to start with.

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Hmmmm... I'm thinking maybe a Drobo might be the best solution for me, because I've read horror stories on dying disks set in a raid config and trying to recover the data. Also Cooper #1 you point out a good point about what/how would I backup all that data. Well another issue with that is I've been backing data for years and have never yet combined all my most important files and documents onto one or 2 disks.

That being said our smartphones today when they take pictures they save them such as img_0394 and so forth. So if I have 3 different pictures with that same file name in 3 different locations, I haven't looked yet, but I'm wondering if there is a app that will scan files and in a nice user-friendly way list same name types possibly auto-rename duplicates or some task to where I won't have to manually rename each file or over write a file.

I have also thought about the dvd solution as well, but is that possible for blueray? Don't the blueray discs store upto like 50GB per disk? I don't currently have a blueray at all, but am looking to do a new build in the new year and create a practical backup solution.

Thanks for all the info so far guys. I really appreciate it! It have given me a bit to think about as far as going with a RAID or another solution.

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DVD vs BluRay is a matter of money vs practicality. A simple DVD holds 4.7GB and costs about 0.30. Double-layer DVD holds 9.4 and costs about 0.90. Single-layer BluRay holds 25GB and costs 1.85 and dual-layer BluRay holds 50GB and costs 5.75. All amounts are prices per disc when bought as a 10-pack and obviously buying more and preferably spindles (couldn't find 10-pack BR-DL disks as a spindle, so that's a box of 10 thin jewel cases). As you can see, the price/GB crown is still held firmly by the humble DVD. Problem is that they fill up mighty quickly so if you have a lot of stuff you need/want to back up, you're going to run into trouble fairly quickly. Also, these numbers are for the non-rewritable disks. A single-layer DVD-RW is 0.50 but a dual-layer BR-RE is 10.00.

Given all of that, I figured I'd get the best bang for my buck on changing data with regular external storage. Transfer rates tend to be much, much better aswell. For truly immutable stuff (photographs and the like) I just take a write-once DVD or BluRay and leave it at that. The directory containing these files are exported by the fileserver via a read-only share and the way to add to the set is to upload to the machine onto the regular storage, then from a shell on the machine itself move the data from there to the appropriate folder. Being read-only prevents accidents. When I first set this up the (now ex) girlie had the annoying habit of making 398256 copies of the same file, preferably in the same folder and preferably with names that have nothing at all to do with the image itself. She hated this setup, which means it worked well. :smile:

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Just curious

apt-get install aufs-tools

mount /dev/sdb1 /media/turdsplash/sdb1/
mount /dev/sdc5 /media/turdsplash/sdc5/
mount -t aufs -o br=/media/turdsplash/sdc5/=rw:/media/turdsplash/sdb1/=rw -o udba=reval none /var/www/html/movies/

my rc.local file...

So, I have mounted 2 hard disk to the same location threw software, what are the the problems you guys can foresee with this kind of setup

Software vs raid

edit: updated

Edited by i8igmac
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What I think you have is a unionfs. Basically one FS on top of the other. Typically the top on is read/write whereas the bottom one is read-only but both can be read-only aswell. What happens is that when you want to open a file on the top filesystem and there's no file there, it falls through to the filesystem below it. If no file is there either, you get a file not found. When you write a new file, it gets written on the top filesystem. When you want to overwrite a file that exists on the read-only filesystem, the edited copy is written to the top filesystem and since the top filesystem is queried first, the correct file is found.

The setup works just fine and is often used on LiveCD/DVDs. I'm sure there are problems for specific cases, but the general concept is sound.

My current setup involves a script that creates soft links to the various files on the harddisks within a structure that exists on all drives (/music /movies /series /other). So in /movies there's movie1 which is a soft link to /mnt/disk1/movies/movie1 and movie8 which is a soft link to /mnt/disk3/movies/movie8

This way, none of the drives gets spun up when I request an non-existing file. Fetching a directory listing doesn't do that either and it's instantaneous since the disk with these links is a really small SSD and will be a MicroSD card with my new build. The only time a disk gets spun up is when I actually follow the link to a file, and then it only spins up the disk containing that one file. Removing files is a bit tedious though.

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@ Cooper, I will be adding a Blueray writable drive to my new build and will probably go with that method. I think a couple 50GB discs would work for most import documents and files. All else is mostly just movies, music, etc. With all the features now in FreeNAS I was thinking of playing with that also.

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@i8igmac - I was just going to ask if anyone had tried aufs. I've seen it mentioned a few times and always wondered how well it worked in practice? I think that both its strength and weakness, when compared to RAID, is actually the same point. That being that when a disk fails you only lose the data on that disk, all the other disks retain their data. So instead of being there being a distinct number of disks that can fail before you lose all your data, you actually end up with a partial loss of data as each disk fails.

As aufs runs at the filesystem level and not at the device level it could be used to merge multiple RAID arrays into one file system, but then I would start to feel that I'm building a house of cards :)

@G-Stress - One important thing for backups that you will want to keep in mind is that the more active you have to be to take them the less likely you are to do them. If you're using optical media for your backups then you'll need to replace them during each backup (unless you're not hitting their limits). This means you have to be about for the back up to run, if you're backing up to a device that has plenty of room for backups then you can schedule a backup script to run at a regular time, and then you won't miss a backup because you didn't have the time free to run it.

Edited by Jason Cooper
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Ewwwwww, DVD/BluRay backups are a bad idea. Shelf life sucks on them.

NIST disagrees with you.

"The results show that high quality optical media with good quality initial recordings can survive several decades in ambient storage conditions."

By "several decades" they mean 20 years minimum.

Life expectancy of a disk is dependant upon several factors such as light exposure, humidity and temperature variations. I'm storing my DVDs in my parents' safe. It's a beast of a box which they don't open very often so I'm willing to bet my DVDs get a relatively gentile treatment in a fairly constant and generally non-hostile environment.

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NIST disagrees with you.

"The results show that high quality optical media with good quality initial recordings can survive several decades in ambient storage conditions."

By "several decades" they mean 20 years minimum.

Life expectancy of a disk is dependant upon several factors such as light exposure, humidity and temperature variations. I'm storing my DVDs in my parents' safe. It's a beast of a box which they don't open very often so I'm willing to bet my DVDs get a relatively gentile treatment in a fairly constant and generally non-hostile environment.

In perfect conditions.

My work deals with 50 TB a month added to the stack of how much we need to keep on average. If you are willing to burn all the Blu-ray and have a climate controlled room for all that, hit me up. Also that article is from 2007 so it really doesn't apply to modern conditions.

Think about it. Blu-Ray store SO MUCH more data in the same size as a traditional CD-R. Yet a CD-R holds much less. Why you may ask?

One reason is the bit density. They are cramming more bits into tighter spaces like they did with hard disks. Now we don't have nearly the tolerance as we did in the past, but hey, now we can store a crap ton more.

With hard disks, it uses ECC to detect when a sector is going bad to re-map the data elsewhere. You can't do that on optical media.

TL;DR: Optical Media is not the best backup solution; NIST is out of date.

In regard to the original post, it would be easier and probably cheaper to build a small RAID system for backups. I will only suggest optical media if you can back up your data to a practical amount of discs (1-3). Another side note: Static data when using optical. It's basically comparing burning the new linux distribution release to a new DVD every time instead of just replacing the ISO file on a thumb drive to boot from.

G-Stress, if you need assistance with the recovery portion, inbox me.

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That's work you're talking about. G-Stress and I are discussing home movies, pictures and the like - stuff that's typically low in volume and not needed very often either.

If you have 50 TB that you need to back up on a regular basis, you're obviously not going to do it on an optical disk. Aside from the slowness of it all and the tediousness of having to replace disks every 5 minutes, you'd have a room filled with optical disks by the end of the year plus the cost involved there would be rather inhibitive.

The best backup solution I know is tape, which is probably what your work uses too, but the initial cost of that is considerable and not something you'd typically see for home use. The only alternative I know of is external harddisk(s), optical disks or a combination thereof, and I personally chose the latter for my specific needs which thus far has been working quite nicely.

And yes, the report is old, but it's not like they suddenly started making shittier dyes for the optical disks. BluRay was out of scope at the time, but the general principle holds.

Yes, they degrade. However they tested at 25 degrees celcius and 50% humidity which might be 'perfect conditions' to you but I think it's mighty hot and humid and not particularly ideal for the organic dye. Our atmosphere didn't change so rapidly that suddenly the degradation process sped up. If you store your disks at relatively constant conditions without a lot of sunlight hitting them, you should be able to reach a decade or two without breaking a sweat. And I'm sure that in just 1 decade alternative backup solutions will either have been developed or gone down in price sufficiently to be viable for home use.

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