[SOLVED] External HDD power down

[rodrigomendoza]

Hello,

I have a B Model connected through 5V @ 1.2A power supply from here and a Western Digital My Passport 1Tb USB 2.0 HDD.

The problem I'm experience is randomly I get this error:
ls: reading directory .: Input/output error
When trying to read a directory from the HDD.

If I do a df -h I see the drive mounted.

If I try to mannually unmount/mount the drive I'll get this error:
xbian@raspberry ~ $ sudo mount -t ntfs-3g /dev/sda1 /media/usb0
Error opening '/dev/sda1': No such device or address
Failed to mount '/dev/sda1': No such device or address
Either the device is missing or it's powered down, or you have
SoftRAID hardware and must use an activated, different device under
/dev/mapper/, (e.g. /dev/mapper/nvidia_eahaabcc1) to mount NTFS.
Please see the 'dmraid' documentation for help.

Can someone help me?
Will a USB Hub with external power solve this issue?

Thanks in advance

---

A little bit more data:

xbian@raspberry ~ $ lsusb
Bus 001 Device 002: ID 0424:9512 Standard Microsystems Corp. LAN9500 Ethernet 10/100 Adapter / SMSC9512/9514 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 004: ID 1058:071a Western Digital Technologies, Inc. My Passport 1TB

xbian@raspberry ~ $ sudo smartctl -i /dev/sda1
smartctl 5.41 2011-06-09 r3365 [armv6l-linux-3.6.11+] (local build)
Copyright © 2002-11 by Bruce Allen, http://smartmontools.sourceforge.net

Smartctl open device: /dev/sda1 failed: No such device or address