On Tue, Jul 08, 2014 at 12:15:54AM +0800, loody wrote:
> so sg_read will not hammer on the page cache like dd without "iflags=direct"
>
> thanks for your kind help,
The sg_read program (and other programs in sg3_utils) sends a command directly
to the device using an SG_IO ioctl. This bypasses all
On Mon, Jul 07, 2014 at 11:39:05PM +0800, loody wrote:
> hi David:
>
> 2014-07-07 23:06 GMT+08:00 David Laight :
> > From: Lars Melin
> > ...
> >> sgread is not included in BusyBox but you should have "touch".
> >> Create a dummy file on the disk and let cron touch it every 4 minutes.
> >
> > You
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
