Spinrite

[Tom Del Rosso]

I have a drive with bad sectors in the FAT area, so I thought of
Spinrite since it works at the low level, but they tell me that their
program can't fix it. I couldn't expect them to explain why, so I'll
ask here.

I had thought that Spinrite relocates sectors at the low level, and as
far as the LL format is concerned the FAT is not special. Track 0 is a
special case, because IIRC that's where the LL format can pick up spare
sectors, but why can't the FAT be fixed?

 

[Rod Speed]

I have a drive with bad sectors in the FAT area,
so I thought of Spinrite since it works at the low
level, but they tell me that their program can't fix it.
I couldn't expect them to explain why, so I'll ask here.

Basically its a scam. It doesnt do what it claims to do.

I had thought that Spinrite relocates sectors at the low level,
Nope.

and as far as the LL format is concerned the FAT is not special.

Nothing can do a real LLF on a modern IDE drive.

Track 0 is a special case, because IIRC that's
where the LL format can pick up spare sectors,

Nope. The spares are even visible.

but why can't the FAT be fixed?

Because the drive is dying.

 

[Joep]

It remains a mystery to me what Spinrite is actually doing ... as a matter
of fact, I believed the same thing as you and thought Spinrite would try to
'cure' those sectors. Or at least I thought that was what they claimed to be
capable of.

Since a while there's this tool HDD regenerator that seems another tool
capable of performing miracles where it concerns bad sectors, I have not
tried it yet. They say they're not relocating sectors.

The solution I use in situations like yours, is one I at least understand :
create a sector by sector clone of the bad drive. The conventional drive
cloning tools probably will fail as they most of the times require a drive
to be error free.

DiskPatch will allow you to clone the bad drive to a known_to_be_good drive,
the contents of the bad sectors will be lost of course, it will skip those
sectors. Once you have cloned the drive try to copy off as much data as
possible. After that scandisk may be used to bring back the file system to a
consistent state.

regards,
Joep

--
D I Y D a t a R e c o v e r y . N L - Data & Disaster Recovery Tools

http://www.diydatarecovery.nl
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Please include previous correspondence!

DiskPatch - MBR, Partition, boot sector repair and recovery.
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[Mark M]

Basically its a scam. It doesnt do what it claims to do.

Hi Rod, I once took a look at Spinrite and it seemed quite clever.
What is so scammy about it?

 

[Tom Del Rosso]

Nope. The spares are even visible.

Visible how?

Because the drive is dying.

I know that. The question was, why does GRC claim the FAT is different.
If I understand you right, the sectors of the FAT can be relocated to
spares like any other sectors, but only by the internal mechanism.

 

[Rod Speed]

I have a 13 gig drive with an odd fault. It has random bad sectors
in about the top 3 gigs. I presume it's a head positioning problem.

Its more likely to be a flakey connection to the heads. Which
only manifests itself with a band of tracks at one end like that.

Scandisk surface check shows the random bad
sectors but spinrite could not find any problems.

Probably because it retrys a particular sector
more so does eventually see the sector.

Long ago I bought an AT with a 20 meg full height hard drive.
Every few months the drive would suddenly show lots of bad
sectors. I used the old version of spinrite to fix them.

Sure, Spinrite did once have a purpose, when the drives
could still be LLFed, it could certainly LLF a track which
was bad. In fact with stepper motor head actuators, that
had to be done occasionally as thermal cycles produced
sector jitter around track average position radially.

That problem is long gone now that none of the modern
drives use a stepper motor for head position and all modern
drives do their own automatic defect management now.

 

[Rod Speed]

Hi Rod, I once took a look at Spinrite and it seemed quite clever.
What is so scammy about it?

The short story is that all modern drives do their own defect management now.

Spinrite did once have a purpose, when the drives
could still be LLFed, it could certainly LLF a track which
was bad. In fact with stepper motor head actuators, that
had to be done occasionally as thermal cycles produced
sector jitter around track average position radially.

That problem is long gone now that none of the
modern drives use a stepper motor for head positioning.

 

[Rod Speed]

Sorry, typo, that should have said

Nope. The spares ARENT even visible.

Visible how?

I know that. The question was, why does GRC claim the FAT is different.

It probably chooses not to do it with the FAT, because
of the ripple thru consequences with a whole bad sector
with the fat. With a file, a problem just affects one file.
With the fat, its much more serious.

If I understand you right, the sectors of the FAT can be relocated
to spares like any other sectors, but only by the internal mechanism.

Correct.

 

[Folkert Rienstra]

It doesnt do what it claims to do.

And what would that be?

I have a 13 gig drive with an odd fault.

I wouldn't be surprised if SpinRite was limited to 8GB, the CHS limit.

It has random bad sectors in about the top 3 gigs.

Which is in that area above 8GB.

I presume it's a head positioning problem. Scandisk surface check shows
the random bad sectors but spinrite could not find any problems.

Presumably because it doesnt test that area.

 

[Joep]

Hmm .... they suggest more, I mean they suggest there method is more
'sophisticated' ... have you ever looked at it's interface and all the hocus
pocus graphs and all that while scanning a drive (Spinrite I mean)?

Read sectors to establish whether there is a problem with them or not.
If there is, Spinrite steps up a notch and tries to read them by many
retries.

Yes, but that's not magic, it will be in the next DiskPatch version as well
.... it is plain dumb trying and see if it works.

If it fails to read a sector there are 2 things it can do:
1 let it stay and add bad cluster to FAT
The problem with that is that the FAT cannot have a bad sector in

itself

Yes, I can understand that, it is what scandisk does. I mean their technique
to revive bad SECTORS, not clusters is what interests me most.

That's odd given the complexity it already must have.
Presumably they meant that the data stays where it is where SpinRite
copies tracks to a safe place before it tests and restores afterwards.

No, what they mean is that they do not use the hdd spare sectors. And yes it
all odd, that's the freaking point I am trying to make. Do they really
perform magic?

 

[Joep]

It's the program as well. What does it do? ... As I read it this is
typically the kind of trouble you can use it for. So, if it can't pull this
one, then what does it do?

 

[Folkert Rienstra]

Hmm .... they suggest more, I mean they suggest there method is more
'sophisticated' ... have you ever looked at it's interface and all the hocus
pocus graphs and all that while scanning a drive (Spinrite I mean)?

Yes, impressive, isn't it? All that from a 94 kB program, 'pure genius'.
Try and beat that, van der Steen.

Yes, but that's not magic, it will be in the next DiskPatch version as well
... it is plain dumb trying and see if it works.

Well, like you said, that is plain dumb.
Spinrite at least takes several different approaches.
Like reading different sectors before returning to the problem sector.
Like reading the contents many times and approximate the original contents.

itself

Yes, I can understand that, it is what scandisk does. I mean their technique
to revive bad SECTORS, not clusters is what interests me most.

Yes, and I told you what it does in the part that you snipped.
Cut the obstinacy and read it again.

No, what they mean is that they do not use the hdd spare sectors.

They have no say in that when the drive decides to do that anyway.
Obviously they must mean something else.

And yes it all odd, that's the freaking point I am trying to make.

Do they really perform magic?

Ofcourse not. They have the same problem as SpinRite has.
If the sector is consistantly bad, it's unrepairably bad.
All that may be left is rewrite the sector with the bad
data but with correct ECC so that it doesnt appear bad.
It may ofcourse go bad again, depending on why it was
bad in the first case.

 

[Folkert Rienstra]

It's the program as well. What does it do? ...

I'm not going to repeat what I already told you.

As I read it

this

What's this "this"?

is typically the kind of trouble you can use it for.

So, if it can't pull this one, then what does it do?

Read the other post.

 

[Rod Speed]

It's the program as well. What does it do? ... As I
read it this is typically the kind of trouble you can use
it for. So, if it can't pull this one, then what does it do?

Can do something when the sector isnt part of the FAT.
But only in the sense that it can encourage the drive to
apply its internal remapping mechanism, and obviously
will be better than nothing if the drive doesnt remap auto.

That last isnt at all common anymore, but there are still a
few older drives around in use that dont auto remap on the fly.

 

[Tom Del Rosso]

Can do something when the sector isnt part of the FAT.
But only in the sense that it can encourage the drive to
apply its internal remapping mechanism, and obviously
will be better than nothing if the drive doesnt remap auto.

If Spinrite does this by formatting the track and forcing the drive to
remap the sectors, then why wouldn't this work with any track, including
the FAT?

 

[Rod Speed]

If Spinrite does this by formatting the track

It doesnt. No modern IDE drive actually formats the track anymore.

The most drives ever do anymore is write zeros thru the sectors
on the track and thats no use to spinrite, all that data is then lost.

and forcing the drive to remap the sectors,

Might as well just write zeros thru the sector its decided
is bad instead. That will at most encourage the drive to
remap that sector, and spinrite can then put the data
back in the replacement sector, which its presumably
obtained by repeated reads of that sector, before it
forced the drive to remap the sector, by writing zeros in it.

then why wouldn't this work with any track, including the FAT?

Yes, it would work, even when done with just one sector.

BUT it cant mark sector/cluster as bad at the OS level
because that isnt possible with the sectors used by the
FAT. That OS level bad cluster marking is actually done
in the FAT entry for that particular bad cluster, the value
in that particular FAT entry is the bad cluster mark.

 

[Svend Olaf Mikkelsen]

I have a drive with bad sectors in the FAT area, so I thought of
Spinrite since it works at the low level, but they tell me that their
program can't fix it. I couldn't expect them to explain why, so I'll
ask here.

I had thought that Spinrite relocates sectors at the low level, and as
far as the LL format is concerned the FAT is not special. Track 0 is a
special case, because IIRC that's where the LL format can pick up spare
sectors, but why can't the FAT be fixed?

What did you pay for this program?

The FAT can be repaired if different sectors of each FAT copy are bad
sectors.

If it is the "bad sectors at write problem", where all sectors written
in one second become bad, typically the same sectors of each FAT copy
will be damaged.

 

[Folkert Rienstra]

Says who?

No modern IDE drive actually formats the track anymore.

So what? As long as that sector is reassigned, who cares?

OK, I had thought there still was an IDE command for ordering the drive
to format a track --

There usually still is, although the command was removed from the ATA
spec long ago.

just not with the direct control software once had.

Should work unless the drive rejects the command.

That remains to be seen.
The formatter may have to command the drive to reassign a sector
using the Format Track command

But I guess it doesn't do that, because that should work with the FAT
even better than for data, since it has 2 copies of the FAT. After
doing this, NDD could use the other FAT copy to fix it.

No BUT except when the reassign fails/doesn't happen.

So the only conclusion seems to be that Spinrite really just uses the
'bad cluster' mechanism,

Nope. God knows where you got that idea from.

and it has no mechanism whatsoever for
relocating bad sectors -- not even encouraging the drive to do it.

Ofcourse it has. It should be obvious by now.

 

[Rod Speed]

OK, I had thought there still was an IDE command
for ordering the drive to format a track

Yes, but the drives just write zeros thru the
sectors on the track now when they get that.

They do that basically for convenient backwards compatability.

-- just not with the direct control software once had.

Correct. Tho that format track command has
been removed from the ATA standard now.

But I guess it doesn't do that, because that should work with the
FAT even better than for data, since it has 2 copies of the FAT.

Correct. Thats what I assume happens from the
available evidence, that it doesnt attempt that.

After doing this, NDD could use the other FAT copy to fix it.
Correct.

So the only conclusion seems to be that Spinrite really just uses the
'bad cluster' mechanism, and it has no mechanism whatsoever for
relocating bad sectors -- not even encouraging the drive to do it.

Dunno, thats less clear with sectors outside the FAT.

This would make their marketing a flat-out lie.

Yep, thats what I meant by the original scam comment.

 

[Tom Del Rosso]

Dunno, thats less clear with sectors outside the FAT.

But why would it be more or less clear for other sectors? If it doesn't
do that in the FAT -- and we just agreed that it could in theory -- then
isn't it logical to conclude that it doesn't force relocation on any
sectors?