usb hdd keep restarting

[Dj YB]

On Tuesday June 15 2010 16:32:51 Patrick O'Callaghan wrote:
> On Tue, 2010-06-15 at 14:00 +0300, Dj YB wrote:
> > hello,
> > 
> > I have a problem, I am using F13 and eversince the install my seagate usb
> > hdd keep on acting strange (losing power and restarting),
> > on fc11 I don't have any problem and it can stay on for ages.
> > 
> > the kernel version I am using is 2.6.33.5-112.fc13.i686.PAE
> > 

> man hdparm
> 
> Check out the -B option in particular, your hd might be doing agressive
> power management.

tried the above:

[root at localhost djyb]# hdparm -B 127 /dev/sdd

/dev/sdd:
 setting Advanced Power Management level to 0x7f (127)
 HDIO_DRIVE_CMD(identify) failed: Invalid exchange

also tried:

[root at localhost djyb]# hdparm -Z /dev/sdd

/dev/sdd:
 disabling Seagate auto powersaving mode
 HDIO_DRIVE_CMD(seagatepwrsave) failed: Invalid exchange

I don't understand why.

by the way,
I switched to my fc11 installation and it also kept restarting.
now, in some point auto mount stopped working for some reason and I was asked 
for my root password to mount the partitions, and from that point on 
everything just worked perfectly.
my assumption then is something in the auto mount process is different then the 
manual mount...
and that along the way something in the hdd (or auto mount) itself changed 
since the problem occurs in both installations.

using kde 4.4.2 in both installations.

in dmesg I see lots of I/O error messages.

I really hope the disk is not lost, it's 500GB of my favorite TV series and 
Movies.

thanks,
YB.