HDD GURU FORUMS
http://forum.hddguru.com/

Correct Dump and Reread Dump Function Question
http://forum.hddguru.com/viewtopic.php?f=27&t=36851
Page 1 of 1

Author:  ddrecovery [ May 21st, 2018, 16:38 ]
Post subject:  Correct Dump and Reread Dump Function Question

I understand the Reread Dump operation, I am using that at the moment to correct the dump via ECC with several passes.

But what is the Correct Dump operation for?

Author:  hddguy [ May 22nd, 2018, 4:28 ]
Post subject:  Re: Correct Dump and Reread Dump Function Question

Correct dump will execute any corrections in the dump and save these corrections into the dump file. Re-read will attempt to re-read source pages that could not be corrected (this map of uncorrected pages taken from the ECC map). I am assuming since you use this your dump would have already been corrected or that this re-read also corrects errors as it re-reads (not entirely sure, I rarely use VNR for ECC correction or dumping)

Author:  ddrecovery [ May 22nd, 2018, 12:48 ]
Post subject:  Re: Correct Dump and Reread Dump Function Question

Thanks for the reply. One more question. What corrections are likely to be made that are not saved to the dump automatically (apart from the source ECC corrections).

Author:  ddrecovery [ May 22nd, 2018, 13:15 ]
Post subject:  Re: Correct Dump and Reread Dump Function Question

I think I have partially worked it out. You can correct ECC from the source chip with the Reread Dump as we know. This puts the corrections into the ECC map file, but does not correct the dump as the ECC element is still in place and is used in the recovery process.

You can then go back and use Correct Dump to physically add the ECC corrections so the original dump.

At least I think that is what is happening.

Author:  p_patryk [ May 23rd, 2018, 5:53 ]
Post subject:  Re: Correct Dump and Reread Dump Function Question

Good day!

VNR has three different modes to correct errors. By pressing yellow button from parameters of ECC element(POWER off/on), VNR does correction(of lime pages) on fly(it doesn't correct errors from dump).
To remove errors from dump we created two modes, first called "Correct dump" does same thing that upper mode but also saves changes.

Second one "Reread dump" does same that "Correct dump" plus it once again reads red pages and if condition of page is enough good (it becomes lime) software does the correction and save good page to dump.

Author:  ddrecovery [ May 23rd, 2018, 8:51 ]
Post subject:  Re: Correct Dump and Reread Dump Function Question

Hi

I was experimenting with this and I have reread the dump and then corrected the dump, so did I correct it twice? Therefore do I need to start again?

Also once the dump is corrected using the ecc map, do we leave the ecc element in place?

Author:  melvin [ May 23rd, 2018, 9:40 ]
Post subject:  Re: Correct Dump and Reread Dump Function Question

Reread is for red blocks in my opinion. Correct makes light green(correctable) dark green(good).
Once the dump is corrected you don't need to turn the ECC on.

Author:  Sasha Sheremetov [ May 24th, 2018, 9:10 ]
Post subject:  Re: Correct Dump and Reread Dump Function Question

melvin wrote:
Reread is for red blocks in my opinion. Correct makes light green(correctable) dark green(good).
Once the dump is corrected you don't need to turn the ECC on.

100% correct.

ddrecovery wrote:
I was experimenting with this and I have reread the dump and then corrected the dump, so did I correct it twice? Therefore do I need to start again?

Also once the dump is corrected using the ecc map, do we leave the ecc element in place?

Basically when you doing dump reread it will bring all changes into dmp file, so no need correction anymore (after first pass all correctable pages will be corrected).
You still can press "correct dump" button even after multiple times reread operation but it will skip all pages.

Author:  ddrecovery [ May 24th, 2018, 11:59 ]
Post subject:  Re: Correct Dump and Reread Dump Function Question

Sasha Sheremetov wrote:
melvin wrote:
Reread is for red blocks in my opinion. Correct makes light green(correctable) dark green(good).
Once the dump is corrected you don't need to turn the ECC on.

100% correct.

ddrecovery wrote:
I was experimenting with this and I have reread the dump and then corrected the dump, so did I correct it twice? Therefore do I need to start again?

Also once the dump is corrected using the ecc map, do we leave the ecc element in place?

Basically when you doing dump reread it will bring all changes into dmp file, so no need correction anymore (after first pass all correctable pages will be corrected).
You still can press "correct dump" button even after multiple times reread operation but it will skip all pages.

When the dump has been corrected, do we remove the ecc element? or leave it in place?

Author:  melvin [ May 24th, 2018, 12:12 ]
Post subject:  Re: Correct Dump and Reread Dump Function Question

Doesn't matter. If ECC is off it's transparent.

Author:  ddrecovery [ May 24th, 2018, 12:15 ]
Post subject:  Re: Correct Dump and Reread Dump Function Question

Okay thanks.

Author:  p_patryk [ May 24th, 2018, 12:18 ]
Post subject:  Re: Correct Dump and Reread Dump Function Question

ECC with disabled POWER(yellow color) doesn't affect on reading speed.
But when dump is already reread, it is good practice to keep ECC element on place, then when you get back to case you can easily understand that dump is w/o errors and go further with case.

Page 1 of 1 All times are UTC - 5 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/