Connecting WD My Book through ESATA vs. USB

[bbbl67]

A friend of mine has a 500GB WD My Book. It's got one wierd issue, and
that is that you can't read its SMART info when it's being connected
via ESATA, but it works perfectly fine when connected through USB. My
assumption was that SMART only works through ESATA not USB, but it
seems to be exactly the opposite here. He's tried the same drive on
two of his computers a desktop running XP and a laptop running Vista,
and it is exactly the same outcome in both systems: SMART info can
only be read when connected through USB. (The drive also has a
Firewire interface, but we haven't bothered testing that.)

Now I have an idea what's going on here, but I wanted to confirm with
others here if my hypothesis is right. I think what's going on here is
that the My Book has some sort of intelligence onboard that sits
between the computer and the actual drive within the My Book. This
controller has more features when connected through USB (and maybe
Firewire) than through ESATA.

Yousuf Khan

 

[Rod Speed]

A friend of mine has a 500GB WD My Book. It's got one wierd issue, and
that is that you can't read its SMART info when it's being connected
via ESATA, but it works perfectly fine when connected through USB.

What are you trying to read the SMART data with ?

My assumption was that SMART only works through ESATA not USB,
but it seems to be exactly the opposite here. He's tried the same drive
on two of his computers a desktop running XP and a laptop running
Vista, and it is exactly the same outcome in both systems: SMART
info can only be read when connected through USB. (The drive also
has a Firewire interface, but we haven't bothered testing that.)

Now I have an idea what's going on here, but I wanted to confirm
with others here if my hypothesis is right. I think what's going on
here is that the My Book has some sort of intelligence onboard that
sits between the computer and the actual drive within the My Book.

Corse there must be with that many interfaces supported.

This controller has more features when connected through USB
(and maybe Firewire) than through ESATA.

It would be unusual for the eSATA connection to not be direct to the drive.
Do you know what format the actual internal drive is, SATA or PATA ?

 

[Yousuf Khan]

What are you trying to read the SMART data with ?

The DLGDIAG utility that came with the MyBook.

It would be unusual for the eSATA connection to not be direct to the drive.
Do you know what format the actual internal drive is, SATA or PATA ?

It's a relatively new model, built around 2007, so I assume internally
it's likely a SATA. As for whether eSATA connection direct to drive, I
am thinking it's direct to interface controller rather than direct to drive.

Yousuf Khan

 

[Rod Speed]

Rod Speed wrote

The DLGDIAG utility that came with the MyBook.

Maybe it just a quirk of that. See if any of the standard tools can see the SMART data when eSATA connected.

It's a relatively new model, built around 2007, so I assume internally it's likely a SATA.

Yeah, thats likely, but not absolutely guaranteed.

As for whether eSATA connection direct to drive, I am thinking it's direct to interface controller rather than direct
to drive.

I didnt mean electrically, I meant logically, in other words its just passed straight thru when used in eSATA mode.

 

[Yousuf Khan]

Maybe it just a quirk of that. See if any of the standard tools can see the SMART data when eSATA connected.

Well, the DLGDIAG util was able to read all of the SMART info from all
of the other pre-existing internal hard disks, both IDE & SATA, not just
from the MyBook. I believe WD supplies DLGDIAG even with its internal
hard disks, not just with its external hard disk enclosures, so it would
have to be able to handle both types of interfaces.

Yeah, thats likely, but not absolutely guaranteed.

Well, I don't know if it's relevant anyways. The SMART info should be
available no matter if its internal interface was IDE, SATA, or even
SCSI for that matter. The only reason it would not be directly available
is if there is intelligence sitting in between.

I didnt mean electrically, I meant logically, in other words its just passed straight thru when used in eSATA mode.

Yeah, that's what I meant also. And that's what I also think isn't
happening here: there is no straight passthru.

Yousuf Khan

 

[Rod Speed]

Rod Speed wrote

Well, the DLGDIAG util was able to read all of the SMART info from all of the other pre-existing internal hard disks,
both IDE & SATA, not
just from the MyBook. I believe WD supplies DLGDIAG even with its
internal hard disks, not just with its external hard disk enclosures,
so it would have to be able to handle both types of interfaces.

Yes, but unless you actually see what the standard tools see SMART
wise, you can be sure whether its some oddity of the hardware or just
that particular version of DLGDIAG thats producing that effect.

Well, I don't know if it's relevant anyways. The SMART info should be available no matter if its internal interface
was IDE, SATA, or even SCSI for that matter.

There is no SMART with SCSI, what is available is something quite different.

The only reason it would not be directly available is if there is intelligence sitting in between.

And that is why I asked.

Yeah, that's what I meant also. And that's what I also think isn't happening here: there is no straight passthru.

That would be a very unusual way to implement it if the drive itself is SATA.

 

[bbbl67]

Yes, but unless you actually see what the standard tools see SMART
wise, you can be sure whether its some oddity of the hardware or just
that particular version of DLGDIAG thats producing that effect.

Well, which tools do you suggest? Freeware preferably.

There is no SMART with SCSI, what is available is something quite different.

Well, I don't know one way or another about the SCSI SMART, so I'll
accede to your point.

That would be a very unusual way to implement it if the drive itself is SATA.

It may be unusual, but it's not inconceivable. I think if WD is
planning to introduce a future My Book mini RAID array of some sort it
may need to virtualize all interfaces in this fashion. In this case, a
single eSATA connection might be in reality be a logical disk volume
rather than just a single disk.

Yousuf Khan

 

[Rod Speed]

Well, which tools do you suggest? Freeware preferably.

I like Everest myself, mainly because the report is much more readable than most.
http://www.majorgeeks.com/download.php?det=4181

Well, I don't know one way or another about the SCSI SMART, so I'll accede to your point.

It may be unusual, but it's not inconceivable.

Sure, but I cant see why anyone would do it that way. What is the point ?

I think if WD is planning to introduce a future My Book mini RAID array
of some sort it may need to virtualize all interfaces in this fashion.

Makes much more sense to do it that way when its necessary given how
aggressively competitive that particular market is with single drive housings.

In this case, a single eSATA connection might be in reality
be a logical disk volume rather than just a single disk.

Sure, but that would make their single drive housings rather uncompetitive price wise.

 

[Yousuf Khan]

I like Everest myself, mainly because the report is much more readable than most.
http://www.majorgeeks.com/download.php?det=4181

I'll pass it along.

Sure, but I cant see why anyone would do it that way. What is the point ?


Makes much more sense to do it that way when its necessary given how
aggressively competitive that particular market is with single drive housings.


Sure, but that would make their single drive housings rather uncompetitive price wise.

Well, you made the point yourself, this enclosure has a tremendous
number of connection interfaces: USB, Firewire, and eSATA. Probably the
chip that handles all of these interfaces is the same whether you get a
single-drive enclosure or a multi-drive array?

Yousuf Khan

 

[Rod Speed]

Rod Speed wrote

I'll pass it along.

Well, you made the point yourself, this enclosure has a tremendous
number of connection interfaces: USB, Firewire, and eSATA. Probably
the chip that handles all of these interfaces is the same whether you
get a single-drive enclosure or a multi-drive array?

The point tho is that it makes more sense to just pass the SATA thru it than to do anything else.

The main market with that chip is still the single drive enclosures.

 

[bbbl67]

The point tho is that it makes more sense to just pass the SATA thru it than to do anything else.

The main market with that chip is still the single drive enclosures.

Okay, so we've been able to run a thorough test using Everest, now. So
the result is Everest did not even bother to look for SMART data when
connected through either Firewire or USB. And while in eSATA, it
presented a SMART panel for the drive, but it was completely empty.

So it's likely that the utility that comes with the MyBook, DLGDIAG,
has a special proprietary method of obtaining SMART data through USB
for its own drives. DLGDIAG isn't able to obtain SMART data for the
MyBook in either Firewire or eSATA, as stated before for the eSATA
case.

Yousuf Khan

 

[Arno Wagner]

Okay, so we've been able to run a thorough test using Everest, now. So
the result is Everest did not even bother to look for SMART data when
connected through either Firewire or USB.

That is normal. There is no standardizes way to access MART data over
these interfaces. The only non-vendor tool I know that can do it
in many cases over USB is "Hard Disk Sentinel":

http://www.hdsentinel.com/usbharddisks.php

The creators program each way the learn about into the tool.

And while in eSATA, it
presented a SMART panel for the drive, but it was completely empty.

Pretty bad. eSATA is full SATA, which means the disk does not
have working SMART support.

So it's likely that the utility that comes with the MyBook, DLGDIAG,
has a special proprietary method of obtaining SMART data through USB
for its own drives.

More likely a special, proprietary way of obtaining special,
proprietary data. Or the USB bridge fakes something for
DLGDIAG. That would be even worse.

Arno

 

[Yousuf Khan]

That is normal. There is no standardizes way to access MART data over
these interfaces. The only non-vendor tool I know that can do it
in many cases over USB is "Hard Disk Sentinel":

http://www.hdsentinel.com/usbharddisks.php

The creators program each way the learn about into the tool.

Very good tool, well worth buying it.

Pretty bad. eSATA is full SATA, which means the disk does not
have working SMART support.

Either that or SMART is forwarded through the USB bridge chip, but not
the eSATA or Firewire bridges.

More likely a special, proprietary way of obtaining special,
proprietary data. Or the USB bridge fakes something for
DLGDIAG. That would be even worse.

That would be pretty bad considering DLGDIAG is supplied by the
manufacturer (Western Digital) with the unit as part of its support utils.

Yousuf Khan

 

[Rod Speed]

bbbl67 wrote

Okay, so we've been able to run a thorough test using Everest, now.
So the result is Everest did not even bother to look for SMART data
when connected through either Firewire or USB. And while in eSATA,
it presented a SMART panel for the drive, but it was completely empty.

That's interesting. If it decides that the drive doesnt support SMART, you dont
get a SMART panel at all. So presumably the passthru when in eSATA mode
has some sort of glitch that prevents the SMART data getting thru properly.

So it's likely that the utility that comes with the MyBook, DLGDIAG, has a special
proprietary method of obtaining SMART data through USB for its own drives.
Yes.

DLGDIAG isn't able to obtain SMART data for the MyBook in
either Firewire or eSATA, as stated before for the eSATA case.

Maybe the problem with eSATA is just the same glitch that prevents Everest from seeing it too.

What does smartctl from a bootable linux CD show ?

 

[Arno Wagner]

Very good tool, well worth buying it.

Either that or SMART is forwarded through the USB bridge chip, but not
the eSATA or Firewire bridges.

There are no eSATA bridges, just non-intelligent bus-drivers.
eSATA and SATA are the same logically.

That would be pretty bad considering DLGDIAG is supplied by the
manufacturer (Western Digital) with the unit as part of its support utils.

Indeed.

Arno

 

[Yousuf Khan]

That's interesting. If it decides that the drive doesnt support SMART, you dont
get a SMART panel at all. So presumably the passthru when in eSATA mode
has some sort of glitch that prevents the SMART data getting thru properly.

It may not be a true passthru in eSATA, it may simply be a virtual
passthru from the USB bridge. In other words, the USB bridge might be
emulating the eSATA connections and pretending to be the disk, when the
actual disk might be sitting behind it.

Maybe the problem with eSATA is just the same glitch that prevents Everest from seeing it too.

What does smartctl from a bootable linux CD show ?

Well, I don't know if I'm going to be able to convince him to bother
with Linux, even if it is just a live-CD boot. However, I've told him
about HD Sentinel, that Arno mentioned, and we'll try that one out soon.
HD Sentinel is an amazing tool, so far as I've been able to see. It not
only does a lot of automatic analysis of disk states, the authors have
also collected a lot of information about many USB bridge chips, and it
can collect SMART data through those chipsets. It's been able to collect
SMART data off of one of my own external USB-only disks, a Lacie 500GB.
Until now, I didn't think I'd ever be able to see SMART data come out of
that external, nor that there was ever any hope of being able to see
SMART off of it. If it can see SMART off of the Lacie, hopefully it'll
see it off of the WD MyBook too.

Yousuf Khan

 

[Arno Wagner]

It may not be a true passthru in eSATA, it may simply be a virtual
passthru from the USB bridge. In other words, the USB bridge might be
emulating the eSATA connections and pretending to be the disk, when the
actual disk might be sitting behind it.

So SATA (disk) <-> USB <-> eSATA?

Sounds overly complicated. eSATA is SATA with different
electrical characteristics, i.e. you just need a switch.
However there is a lot of stupid design out there, so it is a
possibility.

Well, I don't know if I'm going to be able to convince him to bother
with Linux, even if it is just a live-CD boot. However, I've told him
about HD Sentinel, that Arno mentioned, and we'll try that one out soon.
HD Sentinel is an amazing tool, so far as I've been able to see. It not
only does a lot of automatic analysis of disk states, the authors have
also collected a lot of information about many USB bridge chips, and it
can collect SMART data through those chipsets. It's been able to collect
SMART data off of one of my own external USB-only disks, a Lacie 500GB.
Until now, I didn't think I'd ever be able to see SMART data come out of
that external, nor that there was ever any hope of being able to see
SMART off of it. If it can see SMART off of the Lacie, hopefully it'll
see it off of the WD MyBook too.

Looking forward to the results.

Arno

 

[bbbl67]

Looking forward to the results.

Well, here is the results from HD Sentinel. HDS was able to obtain
SMART data off of the WD MyBook both through the USB interface and
the Firewire!!! WD's own internal DLGDIAG util was not able to do the
Firewire interface, just the USB. HDS is truly the ultimate SMART
utility!!!

Oh and none of the utils could get SMART out of the eSATA on the
MyBook. Not even HDS.

Yousuf Khan

 

[Arno Wagner]

Well, here is the results from HD Sentinel. HDS was able to obtain
SMART data off of the WD MyBook both through the USB interface and
the Firewire!!! WD's own internal DLGDIAG util was not able to do the
Firewire interface, just the USB. HDS is truly the ultimate SMART
utility!!!

Oh and none of the utils could get SMART out of the eSATA on the
MyBook. Not even HDS.

Interesting. Looks like your suspicion that the eSATA is
not done right is correct.

Arno

 

[Rod Speed]

Rod Speed wrote:

It may not be a true passthru in eSATA, it may simply be a virtual
passthru from the USB bridge. In other words, the USB bridge might be
emulating the eSATA connections and pretending to be the disk, when
the actual disk might be sitting behind it.

Yes, that is possible, but like I said, it would be a VERY unusual way to implement it.

Essentially because its a hell of lot easier to do a passthru for eSATA instead.

Well, I don't know if I'm going to be able to convince him to bother
with Linux, even if it is just a live-CD boot. However, I've told him
about HD Sentinel, that Arno mentioned, and we'll try that one out
soon. HD Sentinel is an amazing tool, so far as I've been able to
see. It not only does a lot of automatic analysis of disk states, the
authors have also collected a lot of information about many USB
bridge chips, and it can collect SMART data through those chipsets.
It's been able to collect SMART data off of one of my own external
USB-only disks, a Lacie 500GB. Until now, I didn't think I'd ever be
able to see SMART data come out of that external, nor that there was ever any hope of being able to see SMART off of
it. If it can see
SMART off of the Lacie, hopefully it'll see it off of the WD MyBook too.

We'll see...