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Please do not post questions about data recovery cases here (use this forum instead). This forum is for topics on finding new ways to recover data. Accessing firmware, writing programs, reading bits off the platter, recovering data from dust...



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 Post subject: Data rejuvenation strategies
PostPosted: September 13th, 2009, 10:00 
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Joined: September 12th, 2009, 21:21
Posts: 23
Location: Melbourne, Australia
All of my logical drives are in a RAID1 or greater setup. Occasionally (maybe every 6 months) I manually drop a drive then rebuild it, and once that has completed repeat for the other drive(s)

This is intended to rejuvenate data by redoing the magnetic arrangement so that a sector which has a 1% chance of being misread goes back to 0.01% (of course, these are just random figures I've made up to illustrate my point)

I've been looking into how programs like HDD Regenerator and DRevitalize work. Perhaps writing out an intermediate pattern between drop and rebuild may also help preserve the integrity of the sector. Get the flux moving around a bit.

Or is this all just fluff?

Along vaguely similar lines... why can't drives be 100% low level formatted back to factory status with a command or set of commands? Does some other equipment write the initial markers on the platters?

Strange questions at a strange time... it just hit midnight here and I think it's time for bed. :D


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 Post subject: Re: Data rejuvenation strategies
PostPosted: September 13th, 2009, 11:27 
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Joined: July 18th, 2006, 3:05
Posts: 7474
Location: ITALY
@Rowan

I've been looking into how programs like HDD Regenerator and DRevitalize work. Perhaps writing out an intermediate pattern between drop and rebuild may also help preserve the integrity of the sector. Get the flux moving around a bit.

Have you realized exactly what these programs do ? If so (and according to what you have written, the answer is NO) you would have noticed that.... etc. etc.

Or is this all just fluff?

For me, 90%

Along vaguely similar lines... why can't drives be 100% low level formatted back to factory status with a command or set of commands?

You probably don't know how MODERN drives work. You are still in the ST506 era, where "low level format" concept still had sense.
Anyway, with procedures or -depending on model/brand - commands is possible to perform some functions.... (Knowledge is power :mrgreen: )

Does some other equipment write the initial markers on the platters?

If you mean STW (Servo Track Writing) , the answer is YES. According to the technology used, it is the drive itself (under control of STW equipment) that write its servo, OR the platters are prepared individually before assembly.


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 Post subject: Re: Data rejuvenation strategies
PostPosted: September 13th, 2009, 18:09 
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Joined: September 12th, 2009, 21:21
Posts: 23
Location: Melbourne, Australia
BlackST wrote:
@Rowan

I've been looking into how programs like HDD Regenerator and DRevitalize work. Perhaps writing out an intermediate pattern between drop and rebuild may also help preserve the integrity of the sector. Get the flux moving around a bit.

Have you realized exactly what these programs do ? If so (and according to what you have written, the answer is NO) you would have noticed that.... etc. etc.


Ok, so I don't know, so tell me how they work?... :)

I'm not looking to push 5 year old drives until their last breath (and then still keep them going for another 2), just trying to figure out if this is going to keep my data a little safer.


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 Post subject: Re: Data rejuvenation strategies
PostPosted: September 14th, 2009, 3:41 
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Joined: July 18th, 2006, 3:05
Posts: 7474
Location: ITALY
Ok, so I don't know, so tell me how they work?...

No.


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 Post subject: Re: Data rejuvenation strategies
PostPosted: September 14th, 2009, 10:03 
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Joined: September 12th, 2009, 21:21
Posts: 23
Location: Melbourne, Australia
I just noticed FreeBSD's manual page for 'dd' mentions using it to refresh data.

Code:
Do a refresh of a disk drive, in order to prevent presently recoverable
     read errors from progressing into unrecoverable read errors:

      dd if=/dev/ad0 of=/dev/ad0 bs=1m


http://www.freebsd.org/cgi/man.cgi?quer ... ormat=html

This would be done with the file system unmounted, of course.


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 Post subject: Re: Data rejuvenation strategies
PostPosted: September 15th, 2009, 5:37 
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Joined: November 9th, 2006, 15:15
Posts: 2983
BlackST wrote:
Ok, so I don't know, so tell me how they work?...

No.


:lol:


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 Post subject: Re: Data rejuvenation strategies
PostPosted: September 15th, 2009, 13:30 
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Joined: October 19th, 2006, 11:56
Posts: 217
Deja Vu!

doesn't the topic has "Deja Vu" underneath somewhere in the title??
It atleast seemed to me. :mrgreen:

_________________
I just hate spammers...It was a Spammer, who ruined my life!


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 Post subject: Re: Data rejuvenation strategies
PostPosted: September 15th, 2009, 22:06 
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Joined: September 12th, 2009, 21:21
Posts: 23
Location: Melbourne, Australia
I know I'm a noob, but I'm not asking how to restore a HD that is on its last legs, or magically recover data that cannot be read with a mysterious program (which is what most of the 1 post people on here seem to want). I'm simply interested in *decreasing* the chances of data loss in the short term. It stands to reason that over time a magnetic orientation may become slightly weaker, so realigning it periodically (by rewriting sectors) would seem to make sense. Or not?


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 Post subject: Re: Data rejuvenation strategies
PostPosted: September 26th, 2009, 21:49 
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Joined: September 8th, 2009, 18:21
Posts: 15539
Location: Australia
rowan194 wrote:
I know I'm a noob, but I'm not asking how to restore a HD that is on its last legs, or magically recover data that cannot be read with a mysterious program (which is what most of the 1 post people on here seem to want). I'm simply interested in *decreasing* the chances of data loss in the short term. It stands to reason that over time a magnetic orientation may become slightly weaker, so realigning it periodically (by rewriting sectors) would seem to make sense. Or not?


What you are proposing seems logical, but if the magnetic domains needed periodic realignment, then how would the embedded servo information be refreshed? Are older drives suffering from seek problems as a consequence of this? I doubt it.


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 Post subject: Re: Data rejuvenation strategies
PostPosted: September 26th, 2009, 21:58 
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Joined: September 8th, 2009, 18:21
Posts: 15539
Location: Australia
BlackST wrote:
@Rowan

Does some other equipment write the initial markers on the platters?

If you mean STW (Servo Track Writing) , the answer is YES. According to the technology used, it is the drive itself (under control of STW equipment) that write its servo, OR the platters are prepared individually before assembly.


On a clear disc you can seek forever ...

I suppose at least one side of one platter would need to be prepared externally. Then the others could be written internally by the drive using head 0 as a reference. Is that how it's done?


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