WD20EARS and WHS2011

bisk · September 2011

I just installed the Beta version of Scanner on my WHS 2011 server. When I look at the SMART status of one of my WD20EARS drives it reports at non-advanced format. Is this correct or should it be showing up as advanced format?

Alex · September 2011

I've looked into this, and it seems like those drives are reporting non-advanced format. It might be that they're lying on purpose for backwards compatibility.

bisk · September 2011

I had these drives in my WHS v1 server with the jumper enabled. When moving them to WHS 2011 I did remove the jumper and reformat the drives. I'm wondering if they are in fact using 4k or 512? Is there any other way to check?

Alex · September 2011

According to WD, the RS, RX, RSDTL (as in WD20EARS) are 4K.

The way this works is, all legacy OSes assume 512 bytes per sector. And all drives use that as the logical sector count / mapping.

However, in the newer ATA specs. there are fields that should be able to tell the scanner the real sector size. They basically tell you how many logical sectors are there per physical sectors. E.g. 8 would be 8 * 512 = 4096. Legacy OSes would not know about this field and it shouldn't matter.

The scanner reads those newer fields directly from the drive and tells you what it sees, and ideally the pin shouldn't matter.

The pin doesn't actually change the way the sectors are addressed. All sectors are addressed using their logical layout (as in 512 bytes). The pin affects the logical to physical mapping.

As in:

logical -> physical

Without pin:

0 -> 0

1 -> 0 + 512B

2 -> 0 + 1024B

3 -> 0 + 1536B

4 -> 1

5 -> 1 + 512B

6 -> 1 + 1024B

7 -> 1 + 1536B

With pin:

0 -> 0 + 512B

1 -> 0 + 1024B

2 -> 0 + 1536B

3 -> 1 + 0B

4 -> 1 + 512B

5 -> 1 + 1024B

6 -> 1 + 1536B

7 -> 2 + 0B

This is just an example from memory, I don't recall exactly how the pin changes the mapping, but it's along those lines. It just shifts the mapping by 1.

IIRC, this is because XP places the partition on a sector that's not evenly divisible by 4096. And as a result all 4096 NTFS clusters must read 2 physical sectors, so it's a major slow down.

This is all done on the drive and the OS is not aware of this. It just sees sectors and doesn't care about logical vs. physical.

TransientTRP · March 2012

Sorry to dig up an old thread, but I thought this was relevant. I have two drives from WD which exhibit this same problem: WD15EARS and WD20EARX. If I run the WD Align utility, it reports that both drives are advanced format and properly aligned, however Scanner reports them as non-advanced.

I wonder then, is it possible to query the drive in the same way as WD Align to determine if a drive is advanced format? Or is WD doing something non-standard?

backwards1 · December 2012

Same situation for me 9months later. Any insight or new knowledge surrounding this issue with the WD20EARS drives showing up as non advanced 512sector under scanner but show advanced/aligned under WD utility?

Maybe just leave a finally answer for the next guy 9months from now.

AMCross · April 2013

my wd20ears drives reported as non advanced format with no pin installed but my threewd20earx drives are showing as advanced format again with no pins installed

I thought the issue only affect the ears range

so I purchased 3 x wd30earx red drives and all are now showing as advanced ormat

AMCross · April 2013

this also crops up if your using an add in card that doesn't pass the smart data correctly to scanner

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