Recovering a 16Tb Drobo part by part

Discussions on using the professional data recovery program R-STUDIO for RAID re-construction, NAS recovery, and recovery of various disk and volume managers: Windows storage spaces, Apple volumes, and Linux Logical Volume Manager.
pdupreez

Recovering a 16Tb Drobo part by part

Post by pdupreez » Thu May 23, 2013 9:58 am

We have frequent power failures in South Africa, and my 16tb Drobo got corrupted during a recent outage. I have R-Studio, and I can enumerate the files and recover the files just fine. However, my recovery keeps on getting interrupted, again due to power failures, but also because I have to swap hard drives every so often. Given the size of my recovery, it is not possible to manually keep track of what has been recovered and what not.

To do a full scan and save the .scn file will take 8-9 days, which I will never achieve due to the daily power outages, and the longer I take to recover the files the bigger the risk of a permanent failure. Is there any way to get R-Studio to track files recovered and only recover those not yet fully recovered?

Also, when selecting to skip files that already exist on the target hard drive whilst recovering causes R-Studio to also skip partially recover/incomplete files from previous recovery attempts, leaving holes all over the recovery data. Is there no way to compare file size and overwrite only if target file is smaller and skip if the same?

Thanks, your help will be appreciated. My data has been accumulated over twenty years, and is pretty important to me.

Alt
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Re: Recovering a 16Tb Drobo part by part

Post by Alt » Thu May 23, 2013 11:45 am

Probably, the best solution might be a small and inexpensive diesel power generator... Even a lent one.
But back to reality.
1. You don't have to scan the entire disk in a single run. You may use multiple scans - divide the entire disk into smaller but overlapping portions, scan them separately saving the scan info files while scanning, and combine the result by loading the scan info one by one. Read more in our on-line help: Disk Scan, Multiple scans.
2. The same way, recover the files in parts by selecting only those that might fit into the target disk. There's a log panel and you may save the log files by right-clicking the panel and selecting Save LOg to file on the shortcut menu. You may specify which events should be displayed in the log. Read more at our on-line help: R-Studio Settings, Log.

pdupreez
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Re: Recovering a 16Tb Drobo part by part

Post by pdupreez » Fri May 24, 2013 8:14 am

Thanks Alt for the advice, will take that route.

The generator is cheap, the diesel is about $1.50/litre or about$7/US gallon

-Pieter

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Re: Recovering a 16Tb Drobo part by part

Post by pdupreez » Sun Jun 30, 2013 3:21 pm

Is it at all possible to access a drive (recognised and enumerated by R-Studio) through Windows Explorer (sort of a virtual drive) for easier copying of files?

I am trying to recover this 16TB drive and it is excruciatingly slow, and I cannot do a compare and overwrite if size is different through R-Studio, it allows only for overwrite or skip. I have tried the partial recovery, but that is equally frustrating as the enumeration takes very long.

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Re: Recovering a 16Tb Drobo part by part

Post by Alt » Mon Jul 01, 2013 7:46 am

pdupreez wrote:Is it at all possible to access a drive (recognised and enumerated by R-Studio) through Windows Explorer (sort of a virtual drive) for easier copying of files?
No. Actually, a recognized partition is a pure virtual object existing only within R-Studio itself. Simply speaking, it is a set of rules R-Studio uses when processing a certain set of disk sectors.
pdupreez wrote: I am trying to recover this 16TB drive and it is excruciatingly slow, and I cannot do a compare and overwrite if size is different through R-Studio, it allows only for overwrite or skip. I have tried the partial recovery, but that is equally frustrating as the enumeration takes very long.
You can also write all files with the same filename. R-Studio will add some numbers at the name end. Then you can manually leave only those files that are needed. Select Rename on the Recover->Advanced dialog box. R-Studio will add some digital IDs to original file names.

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Re: Recovering a 16Tb Drobo part by part

Post by pdupreez » Mon Jul 01, 2013 7:58 am

I am a bit confused by your last reply. Does that mean I will end up with 5 million files to later manually rename?

Also I noted sometimes a file is recovered halfway when the recovery is interrupted. When the recovery is resumed again, that partial file is not overwritten, but skipped, if you have selected skip on existing during recovery. This results in a huge number of partial files (if you have as many interruptions as we have) with no way of identifying them afterwards. This would also be resolved if external tools can be used on a "virtual" copy of the drive/raid

HINT: Can you consider the idea of "virtual access" to the drive content? That will release a myriad of synchronising tools to ensure drive access is limited to the minimum. Mine have been churning away for 4 WEEKS!!!

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Re: Recovering a 16Tb Drobo part by part

Post by Alt » Tue Jul 02, 2013 4:08 am

Well, R-Studio never has been developed to work under so harsh conditions of constant power interrupts. And I don't know any other data recovery software that has. These words aren't a polite way to send you to fry an egg. I really don't know any solution to your problem except a sort of uninterrupted power supply.

About virtual access. The problem is that when other programs like TrueCrypt, R-Drive Image, and others can connect their files as virtual disks, they work with file-containers which contain all necessary pieces of a real disk: MBR, file tables, etc, which helps OS access the data in its common way. Whereas virtual objects in R-Studio has non of them. They are actually sector areas (or groups of sector areas) on hard drives that should be treated according to some rules stored in its own format inside R-Studio. This format isn't MFT or FAT, or another file table format. That alone makes mounting R-Studio's virtual objects as virtual disks very hard if even possible.

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Re: Recovering a 16Tb Drobo part by part

Post by pdupreez » Tue Jul 02, 2013 4:17 am

Thanks Alt, fried an egg or two, but the problem stayed! :mrgreen:

A UPS would work only if it will keep the unit up long enough until the power comes back on again. The last power failure was 5 days!

I am SOOL I suppose....

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Re: Recovering a 16Tb Drobo part by part

Post by Alt » Thu Jul 04, 2013 9:54 am

I really sympathize with you in your dire straights. I tried to think something up for your situation, but the only idea that I think workable is as follows:
A engine-generator which can provide uninterrupted power, a storage enough to keep all data from the corrupted Drobo, and the Recover all option. Step-by-step sorting the recovered staff out upon recovery.
That might look too expensive, but the generator and storage can be sold away as second-hand, and the money difference looks to me as less spending than myriads "teaspoon per hour" attempts to do some partial recovery. Time is money, as you know.

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