TeraByte Unlimited

What does byte-for-byte validation actually do? Does it re-read and re-compress the source as if it were creating the backup, but just compare the result to what was written in the backup phase?

Reads back the data and compares it to what is in the backup (decompressed).



http://www.terabyteunlimited.com/kb/article.php?id=350


"Bob Coleman" wrote in message news:[email protected]...

What does byte-for-byte validation actually do? Does it re-read and
re-compress the source as if it were creating the backup, but just compare
the result to what was written in the backup phase?

"Reads back the data". From where?

the hard drive and the file.

"Bob Coleman" wrote in message news:[email protected]...

"Reads back the data". From where?

So it reads and processes the image file as if it were going to restore it, but instead of writing anything to the original source, it compares what would be written during a restore to what is already there?

correct.

"Bob Coleman" wrote in message news:[email protected]...

So it reads and processes the image file as if it were going to restore it,
but instead of writing anything to the original source, it compares what
would be written during a restore to what is already there?

If validation is primarily a test of your hardware's ability to restore an image, it it necessary to validate every image. For example, if five images are created daily is it acceptable to only validate one? Or would you suggest all be validated?

On Sat, 5 Jul 2014 16:03:44 PDT, just as I was about to take a herb,
Brian K disturbed my reverie and wrote:

>If validation is primarily a test of your hardware's ability to restore an image, it it necessary to validate every image. For example, if five images are created daily is it acceptable to only validate one? Or would you suggest all be validated?

Putting my paranoia hat on , if hardware can fail at any time, one
should have to validate all the time. I always validate, but very
rarely validate byte-for-byte.
--
Cheers,

DrT

** You've never known happiness until you're married;
** but by then it is too late.

DrTeeth wrote:

> Putting my paranoia hat on , if hardware can fail at any time, one
> should have to validate all the time. I always validate, but very
> rarely validate byte-for-byte.
> --


DrT,

If you were truly paranoid you would validate byte-for-byte. So why do you use ordinary validation when validate byte-for-byte is more thorough? I suspect it is related to time. Time is the argument people use when they don't validate at all. In forums we see people saying they have been restoring images for years, have never validated and have never had a restore failure. So what do we say to these people? Sure, their RAM may fail in five minutes time but practically, how often is enough for validation?

I validate b-f-b when imaging and sometimes validate an image before a
restore. The latter depends on the time I have.

My C partition is 32 GB so not huge.

I figure if Image 1 is not valid, Image 2 probably will be and I WILL
validate that one before the restore.
Mary

On 7/6/2014 4:57 PM, Brian K wrote:
> DrTeeth wrote:
>
>> Putting my paranoia hat on , if hardware can fail at any time, one
>> should have to validate all the time. I always validate, but very
>> rarely validate byte-for-byte.
>> --
>
>
> DrT,
>
> If you were truly paranoid you would validate byte-for-byte. So why do you use ordinary validation when validate byte-for-byte is more thorough? I suspect it is related to time. Time is the argument people use when they don't validate at all. In forums we see people saying they have been restoring images for years, have never validated and have never had a restore failure. So what do we say to these people? Sure, their RAM may fail in five minutes time but practically, how often is enough for validation?
>
>