Hi,
I would like to add support for granular disk controller support for CloudStack
over VMware deployments.
To access virtual disks, CD/DVD-ROM, and SCSI devices, a virtual machine uses
storage controllers.
Virtual storage controllers appear to a virtual machine as different types of
controllers of type IDE or SCSI. Further SCSI controllers can be classified
into 4 sub types, as below
BusLogic Parallel
LSI Logic Parallel,
LSI Logic SAS
VMware Paravirtual SCSI
Currently CloudStack supports following combinations only.
DATA volumes - SCSI controller (LSI Logic Parallel) - Hard coded in source
code, no option for user to edit/choose the controller type
ROOT volumes - IDE or SCSI (LSI Logic Parallel) - Baed on value of global
configuration parameter "vmware.root.disk.controller"
Currently the instances are deployed with the the LSI Parallel controller type.
This might result in failure to boot when attempting to deploy templates that
use the LSI SAS controller.
CloudStack should provide administrator the means to choose the type of disk
controller (including sub types listed in introduction section above) for an
instance. The controller to be used by VM to access virtual disk (volume) can
decided for various reasons. Some of them are listed here,
* Some controllers are optimized for best performance over specific backend
infrastructure like SAN. Ex: VMware Paravirtual SCSI
* Compatibility of some controllers with VM's virtual hardware version or
guest operating system.
* Operating system vendor recommendation and default set of drivers
distributed as part of operating system image. Ex: Windows 8.1 ISO doesn't have
Lsi Logic Parallel SCSI drivers by default. Hence a virtual disk attached to
this controller won't accessible during installation of OS using the ISO.
CloudStack should provide administrator an option which auto detects the
recommended disk controller for the instance's guest operating system and
applicable virtual hardware version.
Kindly let me know your thoughts.
JIRA ticket - CLOUDSTACK-4787
Note:- Detailed Functional Specification is to be added at cwiki.apache.org
under 4.4 Design documents. Currently cwiki.apache.org is down. Waiting for the
site to come up to add the FS document.
Regards,
Sateesh
