On 15.09.2014, at 02:18, NeilBrown <neilb@xxxxxxx> wrote: > It would help to get "udevadm monitor" info to correlate with this. > Presumably some uevent is generated when the spindown happens. udev might > respond to this by reading from the device, which defeats the purpose... > > >> >> here’s the output of blktrace -d /dev/sda during that time. >> https://dl.dropboxusercontent.com/u/3464720/blktrace.tar.bz2 > > That suggest that something is reading the metadata from the device almost > constantly. Mostly a 'kworker' thread. I don't know what would cause that. > > Let's look at the 'udevadm monitor' trace first and see what that shows. here’s the output of udevadm monitor during the spindown cycle while mdadm-3.3 is installed. monitor will print the received events for: UDEV - the event which udev sends out after rule processing KERNEL - the kernel uevent KERNEL[299719.336261] change /devices/pci0000:00/0000:00:06.0/0000:09:00.0/host0/port-0:1/end_device-0:1/target0:0:1/0:0:1:0/block/sdb (block) UDEV [299720.646760] change /devices/pci0000:00/0000:00:06.0/0000:09:00.0/host0/port-0:1/end_device-0:1/target0:0:1/0:0:1:0/block/sdb (block) KERNEL[299780.202901] change /devices/pci0000:00/0000:00:06.0/0000:09:00.0/host0/port-0:0/end_device-0:0/target0:0:0/0:0:0:0/block/sda (block) UDEV [299781.567308] change /devices/pci0000:00/0000:00:06.0/0000:09:00.0/host0/port-0:0/end_device-0:0/target0:0:0/0:0:0:0/block/sda (block) KERNEL[299841.090818] change /devices/pci0000:00/0000:00:06.0/0000:09:00.0/host0/port-0:1/end_device-0:1/target0:0:1/0:0:1:0/block/sdb (block) UDEV [299842.407035] change /devices/pci0000:00/0000:00:06.0/0000:09:00.0/host0/port-0:1/end_device-0:1/target0:0:1/0:0:1:0/block/sdb (block) please note that the issue immediately disappears when downgrading to mdadm-3.2 without touching anything else. I see the udev rules have been updated in mdadm-3.3.. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
