isabella232 / compute-centos5-drivers

Linux virtio_scsi driver RHEL5 / CentOS5 Backport

Overview

This package contains the virtio_scsi driver as backported originally from 3.3 to 2.6.39 and now to 2.6.18 RHEL5 / CentOS5 kernels. These kernels already have some virtio devices backported to it including virtio_net and virtio_blk, but do not support virtio_scsi directly.

This driver allows using these older kernels on with virtio_scsi devices and works with implementations such as qemu and Google Compute Engine.

This is not an official Google product.

Building

This code distribution can work in one of two forms:

Direct KBuild invocation

This driver can be invoked from the top-level directory of configured and built kernel sources:

  $ cd ${HOME}/rpm/BUILD/kernel-2.6.18/linux-2.6.18.x86_64/   # KSRC
  $ make M=${HOME}/virtio_scsi                                # this package

When invoking this way, the driver may require specifying whether it should use find_vq(),del_vq() or find_vqs(),del_vqs(). This can be overriden on the build using the USE_FIND_VQS flag:

  $ cd ${HOME}/rpm/BUILD/kernel-2.6.18/linux-2.6.18.x86_64/   # KSRC
  $ make M=${HOME}/virtio_scsi USE_FIND_VQS=1

Building RPMs

By default, when "make" is run, it will use the included kmodtool to configure and build a kernel module package (.rpm). By default, this will build against the currently running kernel. To build for another kernel version, be sure to have installed the matching kernel-devel package and invoke "make" specifying the KVERSION flag:

  $ make                                # builds rpms for current kernel
  $ make KVERSION=2.6.18-371.12.1.el5   # builds rpms for another version

Booting with the driver (initrd setup)

Be sure to rebuild your initrd to ensure that the driver is available when looking for the boot disk. This is done using mkinitrd on RHEL5, using the /--with/ flag to specify additional modules to include. The virtio_pci driver must also be installed/available in the initrd! otherwise your device will not be found!:

  $ sudo /sbin/mkinitrd --with virtio_scsi --with virtio_pci \
      /boot/initrd-2.6.18-164.el5.img 2.6.18-164.el5