On 06/30/2014 11:48 AM, Andras Horvath wrote:
Hi Everyone,
I've been having an issue for a month or so now that I seem unable to track
down.
I have an external USB drive for backup. When I start copying from the computer
to the external disk, it starts to fail sooner or later. Whether at a large
file or after several small ones, but it fails dropping messages like this
(taken from dmesg):
...
I tested the disk on 2 different computers (one of them is brand new server,
the other is old one serving for years) in 3 different USB covers (they're new
ones too) with 2 different brand new disks. The disks are 2 TB in size (a bit
less actually, around 1.8 TB formatted).
When the errors occur, can you tell if the drive spins down and then
back up?
If so, I have seen similar errors with a pair of bus-powered 2.5 inch
1TB Seagate USB3 drives; it seems like the drives actually draw more
power than the port can deliver for an extended amount of time. I have
to put them on a USB 2 port instead of a USB 3 port to get them to be
reliable for writing (reading seems to never be the problem). You
didn't say if the drives were USB-powered or not, but the port spinning
the drives down would be the first thing I would check.
As to Debian 6 being able to work with it and SL6 not, that could be a
kernel difference where the Debian kernel is waiting and retrying longer
in the case where the drive is spinning down.
If the drive is not bus-powered, it could still be spinning down due to
its green features, and maybe the Debian 6 USB stack is disabling those
features (or at least not complaining about those features) whereas the
SL6 kernel is not as forgiving of drives spinning down or isn't
disabling those features.
