mjnelson99 wrote:
>
> I figure if Image 1 is not valid, Image 2 probably will be and I WILL
> validate that one before the restore.
If an image fails validation due to bad RAM I assume all images will fail validation. Is that correct?
What does byte-for-byte validation
-
Bob Coleman
- Posts: 788
- Joined: Fri Aug 12, 2011 5:58 pm
Re: What does byte-for-byte validation
TeraByte Support wrote:
> correct.
>
> "Bob Coleman" wrote in message news:8305@public.image...
>
> 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?
OK, now I guess I understand what validate byte-for-byte does.
For completeness, what does validate without byte-for-byre do?
> correct.
>
> "Bob Coleman" wrote in message news:8305@public.image...
>
> 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?
OK, now I guess I understand what validate byte-for-byte does.
For completeness, what does validate without byte-for-byre do?
-
TeraByte Support
- Posts: 3628
- Joined: Thu May 05, 2011 10:37 pm
Re: What does byte-for-byte validation
checks that the file passes validation (can decompress, hashs match, etc..)
"Bob Coleman" wrote in message news:8312@public.image...
TeraByte Support wrote:
> correct.
>
> "Bob Coleman" wrote in message news:8305@public.image...
>
> 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?
OK, now I guess I understand what validate byte-for-byte does.
For completeness, what does validate without byte-for-byre do?
"Bob Coleman" wrote in message news:8312@public.image...
TeraByte Support wrote:
> correct.
>
> "Bob Coleman" wrote in message news:8305@public.image...
>
> 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?
OK, now I guess I understand what validate byte-for-byte does.
For completeness, what does validate without byte-for-byre do?
-
TeraByte Support
- Posts: 3628
- Joined: Thu May 05, 2011 10:37 pm
Re: What does byte-for-byte validation
and all validations always ensure they are using different memory than when
created.
"TeraByte Support" wrote in message news:8313@public.image...
checks that the file passes validation (can decompress, hashs match, etc..)
"Bob Coleman" wrote in message news:8312@public.image...
TeraByte Support wrote:
> correct.
>
> "Bob Coleman" wrote in message news:8305@public.image...
>
> 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?
OK, now I guess I understand what validate byte-for-byte does.
For completeness, what does validate without byte-for-byre do?
created.
"TeraByte Support" wrote in message news:8313@public.image...
checks that the file passes validation (can decompress, hashs match, etc..)
"Bob Coleman" wrote in message news:8312@public.image...
TeraByte Support wrote:
> correct.
>
> "Bob Coleman" wrote in message news:8305@public.image...
>
> 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?
OK, now I guess I understand what validate byte-for-byte does.
For completeness, what does validate without byte-for-byre do?
Re: What does byte-for-byte validation
On Sun, 6 Jul 2014 23:45:42 PDT, just as I was about to take a herb,
"TeraByte Support" disturbed my
reverie and wrote:
>and all validations always ensure they are using different memory than when
>created.
Could you put a figure on how 'better' BfB validation is compared to
the regular validation? Putting it another way, can something fail BfB
validation and still pass regular validation and be usable?
BfB validation takes way too long for me to use it routinely here. I
may decide to run my main backup overnight with BfB set.
--
Cheers,
DrT
** You've never known happiness until you're married;
** but by then it is too late.
"TeraByte Support" disturbed my
reverie and wrote:
>and all validations always ensure they are using different memory than when
>created.
Could you put a figure on how 'better' BfB validation is compared to
the regular validation? Putting it another way, can something fail BfB
validation and still pass regular validation and be usable?
BfB validation takes way too long for me to use it routinely here. I
may decide to run my main backup overnight with BfB set.
--
Cheers,
DrT
** You've never known happiness until you're married;
** but by then it is too late.
Re: What does byte-for-byte validation
On Sun, 6 Jul 2014 14:57:57 PDT, just as I was about to take a herb,
Brian K disturbed my reverie and wrote:
>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?
Brian,
You are right. It is the time factor. As a result of this thread I may
run my main backup with BfB set so time is not a real consideration.
In another message, I have asked TBU to try to quantify how much
'better' BfB is over the regular validation. I would never dream of
not validating at all.
--
Cheers,
DrT
** You've never known happiness until you're married;
** but by then it is too late.
Brian K disturbed my reverie and wrote:
>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?
Brian,
You are right. It is the time factor. As a result of this thread I may
run my main backup with BfB set so time is not a real consideration.
In another message, I have asked TBU to try to quantify how much
'better' BfB is over the regular validation. I would never dream of
not validating at all.
--
Cheers,
DrT
** You've never known happiness until you're married;
** but by then it is too late.
Re: What does byte-for-byte validation
I too would like to know how many of you have received a b4b validation failure, and if diagnostics produced a reason for it.
I would think if the failure was due to a memory or disk hardware problem, then just using or accessing a disk/file normally, (like defrag) could do a terrible amount of damage, and B4B validation would not be of much additional benefit to already corrupted files. If the natural error rate is 1 in a zillion, then a bit change too will happen during normal operation, and b4b will not help either. Therefore I would see little benefit in a b4b backup validation, but I might see much more benefit in using b4b validation for a restore operation.
Do you see problems with my assumptions? Maybe CD/DVD's have a higher potential error rate, if that is your media for restore/backup.
I would think if the failure was due to a memory or disk hardware problem, then just using or accessing a disk/file normally, (like defrag) could do a terrible amount of damage, and B4B validation would not be of much additional benefit to already corrupted files. If the natural error rate is 1 in a zillion, then a bit change too will happen during normal operation, and b4b will not help either. Therefore I would see little benefit in a b4b backup validation, but I might see much more benefit in using b4b validation for a restore operation.
Do you see problems with my assumptions? Maybe CD/DVD's have a higher potential error rate, if that is your media for restore/backup.
Re: What does byte-for-byte validation
I backup to an internal HD and then mirror that to an external USB3 HD.
-
TeraByte Support
- Posts: 3628
- Joined: Thu May 05, 2011 10:37 pm
Re: What does byte-for-byte validation
covered in http://www.terabyteunlimited.com/kb/article.php?id=350
"DrTeeth" wrote in message news:8316@public.image...
On Sun, 6 Jul 2014 23:45:42 PDT, just as I was about to take a herb,
"TeraByte Support"
disturbed my
reverie and wrote:
>and all validations always ensure they are using different memory than when
>created.
Could you put a figure on how 'better' BfB validation is compared to
the regular validation? Putting it another way, can something fail BfB
validation and still pass regular validation and be usable?
BfB validation takes way too long for me to use it routinely here. I
may decide to run my main backup overnight with BfB set.
--
Cheers,
DrT
** You've never known happiness until you're married;
** but by then it is too late.
"DrTeeth" wrote in message news:8316@public.image...
On Sun, 6 Jul 2014 23:45:42 PDT, just as I was about to take a herb,
"TeraByte Support"
disturbed my
reverie and wrote:
>and all validations always ensure they are using different memory than when
>created.
Could you put a figure on how 'better' BfB validation is compared to
the regular validation? Putting it another way, can something fail BfB
validation and still pass regular validation and be usable?
BfB validation takes way too long for me to use it routinely here. I
may decide to run my main backup overnight with BfB set.
--
Cheers,
DrT
** You've never known happiness until you're married;
** but by then it is too late.
Re: What does byte-for-byte validation
TeraByte Support wrote:
> covered in http://www.terabyteunlimited.com/kb/article.php?id=350
That article covers the differences between the two validation protocols, but does not quantify how much 'better' one is than the other. I am not sure it is possible to provide it, but this information is what is needed to help users decide which one to use.
Think we can all agree that BfB is better, but by how much? Is the extra benefit worth the extra time it takes?
TIA,
DrT
> covered in http://www.terabyteunlimited.com/kb/article.php?id=350
That article covers the differences between the two validation protocols, but does not quantify how much 'better' one is than the other. I am not sure it is possible to provide it, but this information is what is needed to help users decide which one to use.
Think we can all agree that BfB is better, but by how much? Is the extra benefit worth the extra time it takes?
TIA,
DrT