(http://bugs.debian.org/779412 explanation) There is a general problem with non-permanent block devices settings (hard disks, optical disks, usb storage, ...), that are not restored when resuming from suspend (instead using factory defaults and loosing all pre-suspend settings). And as long as the ata/scsi command set drivers can not save and restore every state register a device may have (impossible?), systemd may ship a viable workaround for this: A systemd unit file could trigger an udev change action upon resume for block devices. This way the same udev rules that set up the devices when they are first plugged, will re-apply their settings after resume. Providing this centrally with the systemd package could avoid that multiple packages ship their own files, resulting in multiple change events triggerd on each resume. Examples for very important (non-permanent) settings are with hdparm (i.e. the important -B hard disk wear settings) https://bugs.debian.org/725284 smartctl/mdadm/lvm/btrfs/zfs/... (i.e. set error recovery timeouts to prevent controller resets and data loss) http://sourceforge.net/p/smartmontools/mailman/message/33501936/ A draft for such a central systemd unit file: [Unit] Description=Trigger all block device udev rules on resume, to re-apply all non-permanent device settings (e.g. smartctl and hdparm rules). After=suspend.target After=hibernate.target After=hybrid-sleep.target [Service] Type=oneshot ExecStart=/sbin/udevadm trigger --action=change --subsystem-match=block [Install] WantedBy=suspend.target WantedBy=hibernate.target WantedBy=hybrid-sleep.target -- 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
