kcatthedog
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Post by kcatthedog on Aug 15, 2016 15:45:29 GMT -6
Hey, So one of my back up drives (hard disk) runs but won't mount in el capitan. I am running two demo disc recovery tools. Question, how do they work ?  If the drive won't mount, how does the software read the disc and recover useable data ? I understand that they do, but how ? |
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Post by johneppstein on Aug 15, 2016 19:10:25 GMT -6
Depends on the software. I remember one program (but not what it's called, might come back to me) that ran beneath the level of the OS and accessed the disk directly, on the level of the actual magnetic domains. Spinrite, I think it was. Don't know if it ran on Mac or just PC, but it could deal with drives from any OS. www.grc.com/spinrite.htmSteve Gibson, the guy behind the program, is an absolute genius and one of the last of the machine language programmers still around. |
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kcatthedog
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Post by kcatthedog on Aug 15, 2016 19:17:53 GMT -6
cool thx OWC the disc manufacturer recommended Data Rescue, which is chugging along as we speak, !
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Post by NoFilterChuck on Aug 16, 2016 1:27:31 GMT -6
once you get it up and running, you should sign up for backblaze.com and safeguard your entire collection of connected HDs in the cloud. ...assuming you have fast upload speed...
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Post by jazznoise on Aug 16, 2016 4:28:15 GMT -6
It depends. Data recovery has varying sucess, but as long as the disc isn't physically damaged and the drive became inoperable during a "read" and not a "write" action, the data itself should be intact.
Basically all you do is get the disc to perform a read action by talking directly to the IDE or SATA controller and then you just read out every data location possible and then parse the data from there, or at least that's what I understood.
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Post by kilroyrock on Aug 16, 2016 13:13:46 GMT -6
if you ever find yourself stuck in an issue where mac or windows (doesn't matter) can't read a disk right, make sure you have a copy of knoppix handy. it's a Linux OS on a cd, that you don't need to load to a hard drive. you can use your computer with the corrupt HD to fix itself. It creates a little ram drive for when it turns on. There are disk fixing utilities that come native to it. Nothing can fix physical damage. www.brighthub.com/computing/linux/articles/64736.aspxThis will tell you all you need to know. Save this thread, you will one day need it, believe me. And yes, it's free! |
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Post by kilroyrock on Aug 16, 2016 13:15:38 GMT -6
Ok I lied. If your harddrive is making a clicking noise, and you're down to last resorts, put that HD in a ziplock bag and suck out all the air. put it in your freezer for an hour. it may shrink enough to allow the arms to swing freer until it warms up. get that sucker in an enclosure and pull off whatever you need. wash rinse repeat until you have what you need. Then throw that HD away, and google RAID
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kcatthedog
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Post by kcatthedog on Aug 17, 2016 7:07:41 GMT -6
So I found an ironic solution, as my premise is that el capitain is the problem ( well documented on various apple/mac related internet sites) and that I doubt that the reduced disk utility functions like the old one did ( it seems to run/complete instantaneously), I remembered that my son has an older mac laptop running , wait for it ,,snow leopard!! ta dah.
Fired it up, it had been under the bed for two years, long story short it identified the header volumes had some problems and 10 minutes later had repaired the drive and it is now recognized fine on my 2012 mbp running el capitain and functioning fine.
hmm,, maybe I will partition a drive and or keep older os's on a thumb drive from now on and back up better !
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If the drive won't mount, how does the software read the disc and recover useable data ?
