Page History

Table of Contents

Bug Reference

CLOUDSTACK-4787

Branch

Apache CloudStack master branch

Introduction

To access virtual disks, CD/DVD-ROM, and SCSI devices, a virtual machine uses storage controllers.

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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.

Purpose

This is functional specification document of feature "Granular SCSI Controller support in CloudStack over VMware deployments" which has Jira ID CLOUDSTACK-4787.

References

• https://pubs.vmware.com/vsphere-51/index.jsp#com.vmware.vsphere.vm_admin.doc/GUID-7A595885-3EA5-4F18-A6E7-5952BFC341CC_copy.html
• http://kb.vmware.com/kb/2004740
• http://pubs.vmware.com/vsphere-4-esx-vcenter/index.jsp#creating_virtual_machines/c_about_paravirt_scsi.html

Use Cases

1. User template already has drivers that can support specific disk controller (listed below). User instances created from this template need to use that specific disk controller to be used to attach volumes to the user instance.
2. Storage infrastructure has high end SAN infrastructure and admin user would like to leverage the high end environment for better I/O performance for user instances. Scsi disk controller sub types lsilogic SAS and PVSCSI are best suited for such environments. Hence user should be able to choose a specific disk controller to be used at cloud level (global configuration setting) or at template level (through an optional parameter that can be supported by API that registers the template)
3. Certain operating system images might not have disk drivers in the OS image from factory by default. In such cases, admin user might want to avoid a specific disk controller, which is not supported by OS by default, to be used during deployment of user instance.
4. Each operating system might have a recommended disk controller specified by the vendor of OS and/or hypervisor that suits best for the pair (OS instance running on specific hypervisor) to the best possible performance. Admin user might like CloudStack to detect the recommended disk controller while deploying user instance and later on use it while attaching volumes to the user instance.

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