disks monitoring for insert, remove, mount, umount events
alternatives:
- in newers linux distributives: findmnt -poll for mounts events and udevadm monitor for disks and partitions events
- dbus + hal/udisk/udisk2
linux kernel "removable" disk property means physical layer and it is equal to external or hotplug device, for example linux/drivers/ata/libata-scsi.c:
/* set scsi removable (RMB) bit per ata bit, or if the
* AHCI port says it's external (Hotplug-capable, eSATA).
*/
if (ata_id_removable(args->id) ||
(args->dev->link->ap->pflags & ATA_PFLAG_EXTERNAL))
hdr[1] |= (1 << 7);