Software to check file integrity ?

  • Thread starter Thread starter zjustice
  • Start date Start date
Z

zjustice

Is there a utility if you have concern over a HD to run against it to check
all the files present to see if they're ok and readable ?

thanks
 
zjustice said:
Is there a utility if you have concern over a HD to run against it to check
all the files present to see if they're ok and readable ?

thanks
Click to expand...

Chkdsk?
 
point taken but something to check the file integrity rather thanthe disk

i'm making this up as i go but hope you get the drift !
 
zjustice said:
Is there a utility if you have concern over a HD to run against it to check
all the files present to see if they're ok and readable ?
Click to expand...

Readable? Yes. OK? Not really. A utility can only read what's there; it
can't know what's supposed to be there. The only way to discover defects
in the content of a file, as opposed to its structure, is to compare it
to another copy known to be correct.
 
Neill Massello said:
Readable? Yes. OK? Not really. A utility can only read what's there; it
can't know what's supposed to be there. The only way to discover defects
in the content of a file, as opposed to its structure, is to compare it
to another copy known to be correct. an
Click to expand...
Right!

For the OP, if the file is readable, it's high probablility that the file
contents have not changed or become corrupted. I.e, you imagine that
someone could create a utility that would change files such that chkdsk
would see them as OK, but the contents were either changed or were
corrupted - but the chances of that happening normally would be quite small.
 
fj said:
For the OP, if the file is readable, it's high probablility that the file
contents have not changed or become corrupted.
Click to expand...

That isnt true if its been recovered.
I.e, you imagine that someone could create a utility that would change files
such that chkdsk would see them as OK, but the contents were either changed or
were corrupted - but the chances of that happening normally would be quite
small.
Click to expand...

Not with recovery.
 
<http://support.microsoft.com/default.aspx?scid=kb;en-us;841290>
Availability and description of the File Checksum Integrity Verifier
utility

Article ID : 841290
Last Review : June 14, 2004
Revision : 1.0

File Checksum Integrity Verifier

SUMMARY
The File Checksum Integrity Verifier (FCIV) is a command-prompt
utility that computes and verifies cryptographic hash values of files.
FCIV can compute MD5 or SHA-1 cryptographic hash values. These values
can be displayed on the screen or saved in an XML file database for
later use and verification.
 
fj said:
Right!

For the OP, if the file is readable, it's high probablility that the file
contents have not changed or become corrupted. I.e, you imagine that
someone could create a utility that would change files such that chkdsk
would see them as OK, but the contents were either changed or were
corrupted - but the chances of that happening normally would be quite
small.
Click to expand...

A bad bit in RAM can corrupt files during a copy. I've seen it happen.
I've also seen a defective address line cause corruption during a copy. In
both cases the system ran quite reliably. Unfortunately the only way to
detect such a problem is by a direct comparison with the original.
 
Previously zjustice said:
Is there a utility if you have concern over a HD to run against it to check
all the files present to see if they're ok and readable ?
Click to expand...

Readable is simple:

tar -cf - / | /dev/null

Integrity check is impossible (in the strong, mathematical sense).

Arno
 
one thing to add

in the past i've used Kaspersky anti-virus , and it found 2 files it said
were corrupted
in its report

they were rar files and opened ok in winrar but i hadnt extracted them

Q) Wondering if this is a useful check ?

thanks

tar - guess your a unix bod , isn't a tar file similar to a zip but doesnt
necessarily have to be compressed ?

thanks
 
Previously zjustice said:
one thing to add
Click to expand...
in the past i've used Kaspersky anti-virus , and it found 2 files it said
were corrupted
in its report
Click to expand...
they were rar files and opened ok in winrar but i hadnt extracted them
Click to expand...
Q) Wondering if this is a useful check ?
Click to expand...

No. Still a decompression attempt is useful for compressed files (those being
the only one that can be checked for integrity problems).
 
Arno Wagner said:
Oh yes. If you made it before corruption happened. Afterwards you cannot.
Click to expand...
Windows 2K and latter have SFC, which can compare system files with originals.
 
Back
Top