HP BL680c XenServer Software Development Kit Guide 4.1.0 - Page 33

XenServer API extensions

27

The network retrieval enables users to install the upstream Red Hat vendor kernel directly from their network

repository. An updated XenServer kernel is also provided on the

xs-tools.iso

built-in ISO image which

fixes various Xen-related bugs.

5.2.3. SUSE Enterprise Linux 10 SP1

This requires a two-round boot process. The first round downloads the kernel and ramdisk from the net-

work repository and boots them. The second round then inspects the disks to find the installed kernel and

ramdisk, and sets the

PV-bootloader-args

to reflect these paths within the guest filesystem. This pro-

cess emulates the

domUloader

which SUSE use as an alternative to

pygrub

. Finally, the bootloader is set

to

pygrub

and is executed to begin a normal boot.

The SLES 10 installation method means that the path for the kernel and ramdisk is stored in the VM record

rather than in the guest

menu.lst

, but this is the only way it would ever work since the YAST package

manager doesn't write a valid

menu.lst

.

5.2.4. CentOS 4.5/5.0

The CentOS installation mechanism is similar to that of the Red Hat installation notes above, save that

some MD5 checksums are different which

eliloader

recognizes.

5.3. Adding Xenstore entries to VMs

Developers may wish to install guest agents into VMs which take special action based on the type of the

VM. In order to communicate this information into the guest, a special Xenstore name-space known as

vm-

data

is available which is populated at VM creation time. It is populated via the

xenstore_data

map in

the VM record.

Procedure 5.3. To populate a Xenstore node

foo

in a VM

1.

Set the

xenstore_data

parameter in the VM record:

xe vm-param-set uuid=

vm-uuid

xenstore_data:vm-data/foo=bar

2.

Start the VM.

3.

If it is a Linux-based VM, install the guest tools and use the

xenstore-read

to verify that the node exists

in Xenstore.

Note that only prefixes beginning with

vm-data

are permitted, and anything not in this name-space will be

silently ignored when starting the VM.

5.4. Security enhancements

The control domain in XenServer 4.1.0 and above has various security enhancements in order to harden it

against attack from malicious guests. Developers should never notice any loss of correct functionality as a

result of these changes, but they are documented here as variations of behaviour from other distributions.

•

The control domain privileged user-space interfaces can now be restricted to only work for certain do-

mains. There are three interface affected by this change:

•

The

xenstored

socket interface, access via

libxenstore

. Interfaces are restricted via

xs_restrict()

.

Section	Page
XenServer Software Development Kit Guide	1
Table of Contents	4
Chapter 1. Introduction	7
Chapter 2. Getting Started	8
2.1. System Requirements and Preparation	8
2.2. Downloading	8
2.3. Installation	8
2.4. What's new	8
2.5. Content Map	8
2.6. Building Samples for the Linux Platform	9
2.7. Building Samples for the Windows Platform	9
2.8. Running the CLI	9
2.8.1. Tab Completion	9
2.9. Accessing SDK reference	9
Chapter 3. Overview of the XenServer API	11
3.1. Getting Started with the API	11
3.1.1. Authentication: acquiring a session reference	11
3.1.2. Acquiring a list of templates to base a new VM installation on	11
3.1.3. Installing the VM based on a template	12
3.1.4. Taking the VM through a start/suspend/resume/stop cycle	12
3.1.5. Logging out	12
3.1.6. \	13
3.2. Object Model Overview	13
3.3. Working with VIFs and VBDs	15
3.3.1. Creating disks and attaching them to VMs	15
3.3.1.1. Creating a new blank disk image	16
3.3.1.2. Attaching the disk image to a VM	16
3.3.1.3. Hotplugging the VBD	17
3.3.2. Creating and attaching Network Devices to VMs	17
3.3.3. Host configuration for networking and storage	17
3.3.3.1. Host storage configuration: PBDs	18
3.3.3.2. Host networking configuration: PIFs	18
3.4. Exporting and Importing VMs	18
3.5. Where to look next	19
Chapter 4. Using the API	20
4.1. Anatomy of a typical application	20
4.1.1. Choosing a low-level transport	20
4.1.2. Authentication and session handling	20
4.1.3. Finding references to useful objects	21
4.1.4. Invoking synchronous operations on objects	21
4.1.5. Using Tasks to manage asynchronous operations	22
4.1.6. Subscribing to and listening for events	22
4.2. Language bindings	23
4.2.1. C	23
4.2.2. C#	24
4.2.3. Python	24
4.2.4. Command Line Interface (CLI)	25
4.3. Complete application examples	25
4.3.1. Simultaneously migrating VMs using XenMotion	25
4.3.2. Cloning a VM via the XE CLI	28
Chapter 5. XenServer API extensions	30
5.1. VM console forwarding	30
5.1.1. Retrieving VNC consoles via the API	30
5.1.2. Disabling VNC forwarding for Linux VM	31
5.2. Paravirtual Linux installation	32
5.2.1. Red Hat Enterprise Linux 4.1/4.4	32
5.2.2. Red Hat Enterprise Linux 4.5/5.0	32
5.2.3. SUSE Enterprise Linux 10 SP1	33
5.2.4. CentOS 4.5/5.0	33
5.3. Adding Xenstore entries to VMs	33
5.4. Security enhancements	33
5.5. Advanced settings for network interfaces	34
5.5.1. ethtool settings	34
5.5.2. Miscellaneous settings	35
5.6. Internationalization for SR names	35
5.7. Hiding objects from XenCenter	36

HP BL680c XenServer Software Development Kit Guide 4.1.0 - Page 33

SUSE Enterprise Linux 10 SP1, 5.2.4. CentOS 4.5/5.0, 5.3. Adding Xenstore entries to VMs

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