Comment by morninglight
1 day ago
ValiDrive was designed to be fast and nondestructive -
In a random, non-repeating sequence, at each of 576 separate evenly spread locations on any drive, ValiDrive reads the current contents of that region. It then fills that region with random “data noise” then reads back the region's contents to verify that the “data noise” was actually stored. ValiDrive then always rewrites the region's original data to restore whatever data may have been originally stored there.
For in-depth analysis, Gibson's "SpinRite" can be used -
The two programs are complimentary but very different. ValiDrive quickly checks for the presence of any storage at 576 locations across a drive's storage media. SpinRite thoroughly, deeply and fully examines, verifies, and exercises any drive's storage media, while also performing comprehensive data recovery if necessary.
So, ValiDrive is a “quickie” test to see whether any storage is present, whereas SpinRite is the heavy hitter that verifies every byte of a drive's storage to verify its integrity and reliability.
SpinRite is a data professional's tool at a hobbyist price - inexpensive, but not free.
https://www.grc.com/sr/spinrite.htm
Validrive is less than 100K bytes! You could download and test it in 10 minutes. That should answer any questions you may have.
Spinrite is for HDDs, sure you can use it on SSDs but that's fairly useless in the best case and actively destructive in the worst case. The whole point of Spinrite is exploiting the magnetic nature of HDDs for recovery, that's the only thing that distinguishes it from other generic block device analysis and data recovery software. For SSDs there are plenty of open source software that will work just as well for reading raw data (but what you get for unallocated blocks is at the whim of proprietary SSD controllers anyway).
Spinrite had utility for combating data loss inherent to the HDD medium... I don't like the idea of ValidDrive because it's a paid user tool to fight fraud, that's a bad incentive, you don't want to benefit from that, it should be free and open.
How is a "write random data and undo it later" test considered "nondestructive"? Unless it has fs knowledge and only does it to unallocated sectors.
But it's also windows only...
SpinRite is not a Windows application. Or were you talking about ValiDrive?
Yeah, though for non-windows (assuming you don’t mind nuking any disk contents), various permutations of dd, md5sum, and pipes work pretty well.
Windows is….. significantly more challenging.
> In a random, non-repeating sequence, at each of 576 separate evenly spread locations on any drive, ValiDrive reads the current contents of that region. It then fills that region with random “data noise” then reads back the region's contents to verify that the “data noise” was actually stored. ValiDrive then always rewrites the region's original data to restore whatever data may have been originally stored there.
Does this test actually spot modern fakes? My understanding was that they typically used simple modulo addressing such that any write was immediately readable, and even large continuous chunks operated perfectly fine, it just also "overwrote" that address every 4GB or whatever.