On Mon, Oct 13, 2008 at 12:19 PM, kenneth johansson <ken@xxxxxxxxx> wrote: > When writing data to /dev/sdb (that is the whole disk and no filesystem) > it starts out ok around 100MB/sec but soon end up doing considerably > worse. For prolonged times lasting several minutes it hovers in the > 20-30MB/sec. Is the application using "O_DIRECT"? If not, could be issue with how VM writeback is (not) working. Can you reproduce this using fio or even "dd"? (See git://git.kernel.dk/fio) grant > > This happens on two different SATA disk one samsung and one seagate and > on both 2.6.26 and 2.6.27 kernel. The disk are connected to the external > esata connector. Controller is 00:1f.2 SATA controller: Intel > Corporation 82801HB (ICH8) 4 port SATA AHCI Controller (rev 02) > > What could be the reason for this ?? reading is no problem. > > > -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
