[CentOS] OT hard disk geometry

Sat Feb 8 01:36:47 UTC 2014
Miguel Medalha <miguelmedalha at sapo.pt>

It seems to me that there's some confusion on your part about what a 
SATA power connector is...

The SATA edge connector is divided in two parts, a larger one and a 
narrower one. The narrower one is the signal, or data, connector. The 
larger one is the power connector.

Some older drives also had an additional common Molex connector for 
power, for compatibility reasons, since at first only a few power 
supplies had the SATA power connector. Note that the Molex connector 
does not enable the hot-plugging and unplugging of SATA drives. This 
needs the 3.3V supply that only the SATA connector provides. As far as I 
can see, the ST3250318AS does not have such a connector.

The manual for the ST3250318AS is here:


On page 28 you can read about the SATA cables and connectors. The pins 
you refer to, which are not present on the WD at the same position, are 
NOT power connections, that is a jumper block as you can read on the 
first image of page 28. The manual states the following:

It is usually not necessary to set any jumpers on the drive
for proper operation; however, if you connect the drive and receive a 
“drive not detected” error, your SATAequipped
motherboard or host adapter may use a chipset that does not support SATA 
speed autonegotiation. If
you have a motherboard or host adapter that does not support 
-Install a jumper as shown in Figure 1 below to limit the data transfer 
rate to 1.5 Gbits per second (and leave the drive connected to the 
SATA-equipped motherboard or host adapter that doesn’t support 
autonegotiation) or
-Install a SATA host adapter that supports autonegotiation, leave the 
drive jumper block set to “Normal operation” (see Figure 1 below), and 
connect the drive to that adapter. This option has the benefit of not 
limiting the drive to a 1.5 Gbits/sec transfer rate.

I think this is not a power connector issue.

The WD is a SATA3 drive (6gb/s). Are you sure that your motherboard 
supports SATA3 drives? Maybe SOME ports support them while others do 
not? If not, can you force the WD to operate in a lower mode? Some 
drives can, either by hardware or software.