On Sun, Jul 06, 2014 at 01:18:03AM +0800, loody wrote: > hi all: > we met a USB Hard Disk that will go to suspend if host stop > sending scsi command over 5mins. > To save the IO, kernel will keep the file in page cache as much as > he can and under this circumstances, the scsi command may disappear > for a while longer enough to cause the device suspend. > > is there any kernel config or module parameter can do the dummy > read or scsi command periodically? No but you could set up a simple cron job to call an sg3_utils command. E.g. issue an sg_read for one sector to the device every 4m: */4 * * * * sg_read count=1 if=/dev/<disk> You'll probably want to disable mail notification for the job or have it dropped or it'll get a bit noisy running that frequently. Regards, Bryn. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
