Hi Lamar, On Mon, 30 Jun 2014 13:18:12 -0400 Lamar Owen <[email protected]> wrote:
> 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. Actually the drive has its own power so it is not USB powered. I cannot tell if the drive spins down (did not get the idea to check it), but the CPU is in 100% I/O wait all the time after this happens. I was told the disk is a WD RED, but I'll check the power mode later with hdparm. Thank You for the suggestions. Andras
