Dracut contains tools to create a bootable initramfs for 2.6 and newer Linux kernels.
Unlike existing implementations, dracut does hard-code as little as possible
into the initramfs. Dracut contains various modules which are driven by the
event-based udev. Having root on MD, DM, LVM2, LUKS is supported as well as
NFS, iSCSI, NBD, FCoE with the dracut-network package.

The sg3_utils package contains utilities that send SCSI commands to
devices. As well as devices on transports traditionally associated with
SCSI (e.g. Fibre Channel (FCP), Serial Attached SCSI (SAS) and the SCSI
Parallel Interface(SPI)) many other devices use SCSI command sets.
ATAPI cd/dvd drives and SATA disks that connect via a translation layer
or a bridge device are examples of devices that use SCSI command sets.

Udev creates and removes device nodes in /dev for devices discovered or
removed from the system. It receives events via kernel netlink messages
and dispatches them according to rules in /lib/udev/rules.d/. Matching
rules may name a device node, create additional symlinks to the node,
call tools to initialize a device, or load needed kernel modules.