Rebuilding RAID from Apple MacPro Classic 4.1 Hardware RAID-5 (4 drives)

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.
Alt
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Re: Rebuilding RAID from Apple MacPro Classic 4.1 Hardware RAID-5 (4 drives)

Post by Alt » Sun May 19, 2019 5:10 pm

Please test our new version.

winguru
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Re: Rebuilding RAID from Apple MacPro Classic 4.1 Hardware RAID-5 (4 drives)

Post by winguru » Mon May 20, 2019 10:01 am

Thanks for the heads up!

I tested the new version (8.10.173981) and found that the raid configuration looks better. I am able to delete the default 4-block sequences and create new 3-block sequences as expected. So that part looks correct now, as shown below:
RAID Configuration - Version 8.10.173981.png

However, I am still seeing the same issue where 1/4 of the blocks show as "not checked". I have tried different variations, but all of the custom 3-block sequences seem to exhibit the same behaviour. Again, I am not sure how much to make of this, but it appears as though there is still something amiss, as shown below:
RAID Consitency Check - Version 8.10.173981.png

As a test, when I took the last 3-block sequence and marked them all as ignore, I did not see the "not checked" blocked issue. Obviously this RAID configuration would not be appropriate, but it seems to indicate something internally may not like having 4 "3-block" sequences instead of 3 "4-block" sequences.

I will continue to investigate, and I appreciate all of your support thus far...

Thanks!!
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Alt
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Re: Rebuilding RAID from Apple MacPro Classic 4.1 Hardware RAID-5 (4 drives)

Post by Alt » Mon May 20, 2019 1:22 pm

My understanding is that:
1. Offset is surely incorrect. Must not be 0. But this is not the source of the problem.
2. My understanding is you should look at block size.

winguru
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Re: Rebuilding RAID from Apple MacPro Classic 4.1 Hardware RAID-5 (4 drives)

Post by winguru » Mon May 20, 2019 5:34 pm

Well, after much trial and error, it looks like I may have stumbled across the correct settings. Perhaps a combination of blind luck and getting dirty with the MBP/GPT and partition details, verifying expected LBA sectors match virtual RAID data, etc. I was able to mount the HFS+ partition without errors and examined a few test files and they look to have no artifacts, errors, or other signs of corruption.

For what it's worth, here are the settings I used:
RAID Configuration - Working.png

Here is the RAID consistency check:
RAID Consistency Check - Working.png
I still don't know what to make of those "not checked" blocks, but it doesn't seem to affect the actual data recovery.

Thanks again for all your support, and let me know if you would like any follow up information. Now that I have a known good configuration, I can rest a bit easier :D
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Alt
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Re: Rebuilding RAID from Apple MacPro Classic 4.1 Hardware RAID-5 (4 drives)

Post by Alt » Tue May 21, 2019 12:02 pm

winguru wrote:
Mon May 20, 2019 5:34 pm
Well, after much trial and error, it looks like I may have stumbled across the correct settings. Perhaps a combination of blind luck and getting dirty with the MBP/GPT and partition details, verifying expected LBA sectors match virtual RAID data, etc. I was able to mount the HFS+ partition without errors and examined a few test files and they look to have no artifacts, errors, or other signs of corruption.
How large they are? Larger than 3x(Block size)? If yes, the RAID parameters are surely OK.
winguru wrote:
Mon May 20, 2019 5:34 pm
I still don't know what to make of those "not checked" blocks, but it doesn't seem to affect the actual data recovery.
I've just noticed that one disk is of another model. Does the number of its sectors on this disk _exactly_ match that on others? Maybe, this is the answer?

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