Table
of Contents
Introduction
XenMan is an intuitive, graphical management tool aimed at
operational life cycle management for the Xen virtualization platform. XenMan is built on the firm design
philosophy that ease-of-use and sophistication can, and should,
co-exist in a single management tool. So, XenMan should hopefully
prove valuable to both seasoned Xen Administrators as well as those
just seeking an introduction to Xen Virtualization.
Definitions
VM |
Virtual machine (Xen Virtual Machine in this context) |
Server |
Refers to a physical host or machine |
Client Machine |
Server on which the XenMan is invoked is referred to as
client machine. |
Managed Server |
Server to be managed using XenMan. |
Server Pool |
A collection of managed Servers typically owned/managed
by a department or used to provide related
services/applications. |
Whats New in
v0.6?
XenMan v0.6 greatly enhances some of the key multi-server
management features first introduced in v0.5. Moreover, a
comprehensive, multi-server monitoring feature is new in this
release. The major changes are, briefly:
Multi-Server performance
and
availability metrics are now available in
a single, consolidated
dashboard. Common administrative tasks may
be performed directly
from the dashboard.
The Image Store,
provisionable image
structure and the VM provisioning
mechanisms have all been
completely overhauled and vastly improved.
The new system is
highly flexible, configurable and very well suited for
users
wishing to define and/or use their own provisionable images/schemes.
Deployment
Instructions
XenMan is distributed both as a source/binary tarball and as a
binary rpm for a few specific distributions** (see the important note
at the bottom). Depending on your method of installation, the
deployment procedure may differ slightly.
I. Deployment
from tar ball
1. cd to the location where you've extracted the tarball.
e.g.> cd
~/xenman.0.6/
2. Make sure your environment fulfills
XenMan's pre-requisites. Consult the client and managed-server
configuration sections contained in the main README under the ./doc
directory.
3. If you haven't already, deploy python-paramiko
(an SSH client library XenMan uses for remote management) in your
environment. Python-Paramiko is available for download at:
http://www.lag.net/paramiko.
(follow the installation instructions at the site carefully).
4. Execute the default configuration script if you see one
for for your distro. (e.g. configure_defaults-suse.sh for SUSE):
e.g. > sh
./distros/suse/configure_defaults-suse.sh
5. If you see
a default configuration file for your distro in the distros area
(e.g. ./distros/fedora/xenman.conf for FC), rename it to xenman.conf
and copy it to the top.
e.g. > cp
./distros/fedora/xenman.conf ./xenman.conf
NOTE: If you
do not see a default configuration file specific to your distro,
don't worry, XenMan will create one for you upon startup.
6.
Create a local copy of the Image Store (XenMan's provisionable
Virtual Machine Image repository)
e.g. > sh ./mk_image_store
(this will
create the Image Store at /var/cache/xenman/image_store)
7.
Make sure XenMan has execute permissions:
e.g. > chmod 0755 ./XenMan
8.
Run XenMan and enjoy!
e.g. > ./XenMan
II.
Deployment from an RPM package
1. Remove any earlier versions of xenman from your
environment.
e.g.> rpm
-e xenman
2. cd to the directory you've downloaded the
rpm package to and
install XenMan:
e.g.> rpm -Uvh
xenman-0.6.1.fc5.noarch.rpm
If all goes well, you are
good to go. Run XenMan and enjoy!
e.g.> xenman
NOTE: XenMan
requires the python-paramiko package for remote operations over SSH.
A python-paramiko rpm package is available for most distro's;
however, if you cannot locate a suitable package for your distro, you
can manually deploy it (see section I.3 above), and then run rpm with
dependency checks disabled.
e.g.>rpm
-Uvh xenman-0.6.1.suse.noarch.rpm --nodeps
XenMan is distributed both as a
source/binary tar
ball and as a binary rpm for a few specific distributions** (see the
important note at the bottom). Depending on your method of
installation, the deployment procedure may differ slightly.
Prerequisites
Prerequisites for running XenMan :
Client Machine :
-
Xen 3.0.2 or later
installed.
-
X server (to display
XenMan UI)
-
Ability to connect to
Managed Server through SSH
-
Paramiko library (if
you have problems installing along with xenman)
-
XenMan installed
Managed Server :
Environment
setup
This section describes some additional setup for managing
multiple
Server.
This is NOT required if you want to manage virtual
machines on local host/client machine only.
Xen Server
setup
On the server to be managed,
the Xen daemon
(xend) needs to start listening using tcp-xmlrpc.
To enable this,
follow the following instructions.
- login as root
- uncomment the following line in /etc/xen/xend-config.sxp (change no
to yes)
(xend-tcp-xmlrpc-server yes)
- and restart xend service
# service
xend restart
SSH
setup
XenMan uses an ssh tunnel to communicate to with
the Xend
server. In addition, it needs to read a bunch of
configuration
files, create VBDs, LVMs and give few other remote
commands.
Basically all managed servers need to trust all client
machines. (Yes, u can have more than one client machines)
From client machine, ssh to managed server from the client machine
using the account
from which xenman would be started.
# ssh <managed server
name>
This will prompt you to add the key to the known_hosts. Say yes.
This will add the /etc/ssh_host_key.pub from the managed server
to users $HOME/.ssh/known_hosts on client machine
(Alternatively you can manually add
it)
## Repeat above steps for each managed
server.
If you want to use password based
authentication, the you are done.
You can skip the
rest of the section.
For a small environment it
may be OK to use password based authentication,
but in a
large setup we recommend using key based authentication for
convenience and tractability.
Refer to SSH
manuals and on line material for setting up key based trust and
using ssh-agent.
Here are some useful
URL's
http://www.suso.org/docs/shell/ssh.sdf
http://www.linux.ie/articles/tutorials/ssh.php
Remote file
browsing
While managing remote servers, there are operations like,
"Open
VM File" etc that would require selecting a file on a remote
server. For GNOME users, XenMan uses gnome-vfs to browse files on the
remote server. Unfortunately this is done on a separate channel and
hence would require user to enter the password again for the
managed server. When prompted for saving the password, it is
recommended not to save password in key-ring for security
reasons.
The user is NOT prompted for password if the key
based authentication is used. The user experience is quite seamless
between localhost vs remote managed server management.
NOTE : There is a small bug in paramiko library used by XenMan. The XenMan
distribution contains the necessary files to patch this bug. In order
to apply this patch,
If you have paramiko 1.6.4 or later, then
you do not need to apply the patch.
Use the patch_paramiko script
as root.
# cd <xenman install>/patches
#
./patch_paramiko
XenMan
Features
The Dashboard
The Dashboard is a
consolidated listing of
all known managed servers along with critical performance,
availability and configuration metrics for each. It provides
the user the ability to ascertain the state of his/her entire
deployment at a glance. In addition, most common administrative tasks
can be launched by right clicking on a server.
- Launch.
The Dashboard may be launched by selecting 'Server Pool' in the
navigator on the left and then clicking on the Summary Tab on the right
hand side. (Note: Upon startup, XenMan
launches the Dashboard by default).
- Operations:
Left-Clicking a row in the Dashboard selects the associated managed
server. The following actions may be then be performed:
- Double-Click:
Connect to the managed server (if necessary) and drill down into a more
detailed view. This selects the server's node in the navigator on the
left hand side and brings up the Summary tab for the server on the
right.
- Right-Click:
Context sensitive menu. Most server operations can be executed directly
here.
- Sorting:
Clicking on the column header will re-sort the listing based on the
clicked column. (not available for all columns)
- Data*.
Each row in the Dashboard corresponds to a managed server. The fields
are:
- Server.
The name of the managed server.
- Connection.
Connectivity status to the managed server ( i.e. whether
XenMan has an active connection to the server).
- VM Summary.
A compact listing of VM status on the server.
Total(known)/Running/Paused/Crashed respectively.
- VM CPU(%).
Aggregate processor usage by VM's running on the server.
(Does not include the host OS/Domain-0's processor usage).
- VM Mem(%). Aggregate
memory usage by VM's running on the server. (Does not include the host
OS/Domain-0's memory usage).
- Server CPU(s).
Number and clock speed of the physical processors
on the managed server. (if available)
- Server Mem.
Total, usable physical memory installed
on the managed server. (if available)
- Version. The version string
being reported by Xen at the managed server.
* Most
of the data fields in
the Dashboard listing are available for managed servers running Xen
v3.0.3 or above. For servers running earlier versions of Xen, most
fields will display N/A.
Server Pool
Operations
XenMan shows a Server
Pool node which
refers to a pool in which all managed servers belong. XenMan supports
only one server pool in this release.
A Local server is
automatically added to the pool, if prerequisites are met. XenMan
would manage Virtual machines on the local server.
- Add
Server : Additional remote managed servers can be added by using the
"Add Server" operation.
You are prompted for
basic information:
* Host name : Name of the
server/host to be added.
* Xen Port : Port on
which Xen Daemon (xend) is listening. Typically 8005
* username : (typically root)
* password
: (NOT SAVED ANYWHERE ON DISK/can be left blank if
authentication is done using keys)
One needs to make
sure that Xen daemon (xend) listening on port 8005 on managed
server.
If not,
- login as root
- uncomment
the following line in /etc/xen/xend-config.sxp
(xend-tcp-xmlrpc-server yes)
- and restart xend
service
#service xend restart
Also,
make sure that you can use ssh to login to the managed
server.
Remove Server : A server can be removed from the list,
by selecting it
and choosing "Remove Server"
Server
operations
The following operations are allowed on a managed server.
-
Start All VMs : Start all VMs on a selected server.
- Shutdown
All VMs : Shutdown all VMs on a selected server.
- Kill
All VMs : Kill all VMs on a selected server.
- Provision
VM: Allows you to create a new VM with very few
parameters. (see
section on Image Store for more details)
- Open VM Config File
: Allows you to add a new VM file to the list
which can then be
edited using the settings context menu or started
using the start
button.
Virtual
Machine/VM operations
Edit VM Settings :
Change the
configuration settings for the selected VM
Edit VM Config File :
Edit the VM's configuration file directly.
Start
: Start
the selected
VM
Pause
: Toggle
button to Pause/Resume running VM
Reboot
: Reboot a selected VM
Shutdown : Shutdown a running
VM
Kill
: Hard kill on a VM
Snapshot : Save state of a
running VM to a file
Restore : Restore a VM
from a stored snapshot.
Delete :
Delete VM file and associated VBD/LVMs.
Remove VM Config File
: Removes VM file name from the list of VM known to xenman.
XenMan and
user accounts
XenMan can be invoked from either root user or non-root user
account
-
Non root user : When XenMan is invoked from non-root
account, it can not do Xen management on local server.
However, this user can manage other managed servers. Wherever
necessary, XenMan prompts for credentials..
The Image
Store
XenMan allows administrators to define their images and create
Virtual Machine configurations from them. For example, in a
particular data center, four types of machines are to be provisioned
frequently. They are Red hat, CentOS, Suse and Ubuntu. You
can
configure XenMan to point to kernel and ramdisk of each of
these distributions and install/deploy many virtual machines using
predefined images. The collection of images are referred to
as
Image Store.
XenMan ships with a default image store
containing a few useful provisionable images. Sophisticated users may
also construct their own, arbitrarily sophisticated image
descriptions and provisioning schemes and add them to the Image
Store. (For instructions on how to build custom provisionable images,
please consult the 'Image Builder's Guide,' a part of this
documentation set).
- Location.
The Image Store is listed in the navigator. Clicking or expanding the
Image Store node results in a listing of the available, provisionable
images.
- Image
Operations.
- Click.
selects the image and displays useful information about it in on the
right hand side. This information typically included a brief
description of the provisionable image, pre-requisites and deployment
instructions. So, read this information carefully before attempting to
provision the image.
- Right Click.
brings up a context menu with various image specific tasks. These
are:
- Provision.
Start the provisioning process. Launches a dialog prompting for the
managed server to target for provisioning.
- Edit Settings.
Alter the definition of the image. Any changes made here are permanent
and apply to all subsequent VM's provisioned using this image. (more
detail below)
- Edit Script.
(Advanced Feature). Alter the mechanism used to provision VM's using
this image. This is an advanced feature and should be left alone unless
you are designing your own provisionable image.
- Edit
Description. (Advanced Feature). Edit the description
associated with this image. This is the description that appears on the
right hand side once the user left-clicks on an image name in the
navigator. Unless you are designing your own provisionable image, leave
this alone.
- Edit
Settings Dialog. This is a multi-purpose, context sensitive
dialog that can be launched to manipulate settings
for provisionable images or existing VM configurations. When
launched in context of an image, this dialog presents two top-level
tabs, each affecting a different aspect of the provisioning
process:
- Virtual
Machine. This tab controls the various parameters and
settings controlling the configuration* of the VM's
provisioned with this image. In typical usage, user will likely not
make any changes here, save for perhaps changing disk settings to
better match the deployment environment.
- Provisioning. This tab controls the
various parameters and settings controlling the mechanism*
by which VM's are provisioned using the selected image. A typical
alteration here would be to change the disk size and type parameters
governing the default sizes and types (VBD/LVM) of system disks created
during provisioning process.
* a
detailed
description of the configuration/mechanism distinction and how
parameters may be shared between the two is an advanced topic, more
fully addressed in the 'Image Builder's Guide.'
XenMan config
file (xenman.conf)
XenMan's default configuration is kept in the xenman.conf
file.
This file is in simple text format, so it can be easily changed to
suit your environment.
Here is a brief description of
important configuration parameters:
PATH section
This section contains default directory/file locations. Some
important one's include:
- disks_dir: This is the location
where XenMan creates Virtual Block
Devices (VBD's) for use
as disks by VMs. Make sure you have plenty of space
available at this location. XenMan would prompt for this location if
not
already set.
- snapshots_dir: This is the
location where XenMan stores snapshots of running
VMs for
the Snapshot/Restore. XenMan would prompt for this location if not
already set.
- cache_dir: This is the location where XenMan
stores the default kernel and
ramdisk images. By default,
this is set to /var/cache/xenman.
(See ramdisk/kernel &
staging_location above).
- xenconf_dir: This is the location
for storing and retrieving VM
configuration files. By
default, this is set to /etc/xen.
- image_store: This is the
path variable setting for image store. Typically not changed.
-
log_dir: This is the location where XenMan writes its logs. By
default, this is set
to /var/log/xenman
- exec_path: This
is the path variable setting for remote shell operations. Default
value is
$PATH:/usr/sbin.
APPLICATION
section
This section keeps application specific data.
- vms
: List of virtual machine configuration files being managed by
XenMan.
ENVIRONMENT
section
This section contains server environment information.
-
lvm_enabled : if the server has lvm and want XenMan to create LVM for
new VMs.
Managed
Server specific Sections
The config file has section for each manged server. This
contains
information required by XenMan to connected managed servers. This
sections are relevant only on client machines.
example :
[192.168.0.102]
is_remote = True
login =
root
xen_port = 8005
CLIENT
CONFIGURATION section
This section contains items specific to client/user preferences
-
gnome_enabled : True/False. Set this to True if you are using XenMan
on
Gnome desktop and have patched paramiko. See section on
Remote File Browsing for more details.
Additional
Notes:
* Upon startup, XenMan looks for xenman.conf, in order, at
the
following locations:
./xenman.conf
- (current directory)
~/.xenman/xenman.conf -
(user's home
directory)
/etc/xenman.conf
-
(global location)
If it doesn't find a valid, writable
configuration file, XenMan creates
a default file under
the current directory.
Tips
-
Always specify full
path of the files, as if seen from the managed server.
-
Do not add localhost or
ip addresses using Add Host.
-
XenMan does not allow editing VM config files NOT
generated via XenMan. It looks at special header (first line) to make
this determination. If the config files contains simple name
value pairs and are not parameterized, they you may
selectively choose to add the XenMan file header.
Known
bugs/caveats
- When using XenMan in Xen 3.0.3+/3.0.2 mixes environments, please
ensure that XenMan is run on a 3.0.3+ node. XenMan running on a 3.0.2
node isn't forward compatible for managing Xen 3.0.3+ servers.
- Occasionally, the memory/cpu usage percentages displayed in
the
Dashboard and elsewhere may spike momentarily to above 100%. This is
due to a bug in the way Xen reports resource usage for VM's. Hopefully this will be fixed in the near future.
-
You might have to enter credentials for the same server multiple
times when password based authentication scheme is used for
managed server as opposed to key based authentication.
For example :
- When the server is
expanded
- When terminal window is opened for
selected VM
- When an operation requires remote
file access and gnome-vfs is enabled in XenMan configuration.
- Sometimes, the guest VM tab
showing the virtual machine terminal fails to redraw properly.
Clicking on the terminal and sending a Ctrl+l and/or some keystrokes
often helps.
- When the Virtual machine configuration file is
changed, the directives may get saved in different order.
-
On some platforms the password field generates gtk/pango warnings and
displays "?" characters. Ignore this, the password is read
correctly by XenMan.
- For XenMan to show vnc display
correctly, vncunused in the vm config
file should be set to 0.
- The image store is no more
governed by entries in xenman.conf. Users upgrading will have to use
the new mechanism of defining and using images.
- A property
name in the xenman.conf has changed from "doms" to "vms",
please make a note of this.
Platforms
Fedora Core 5
OpenSUSE 10.1
Xen 3.0.2
Licensing
GNU General Public License (GPL)
For details, see:
http://www.gnu.org/licenses/gpl.html
Feedback
Do drop us a line, if you download/evaluate/use XenMan. We
would
appreciate feedback on the current release as well as suggestions for
future releases.
Also, we are hoping for active community
assistance in the following areas:
- packaging for more
platforms and distributions. (e.g. debian, windows, etc.)
-
ImageStore images (kernel/ramdisk pairs) for various pre-packaged
Guest Os/VM's.
The best way to reach us is to pop in and say
hi at our (low frequency) mailing list. To sign up, visit
http://xenman.sf.net/. We look forward to hearing from you!
Copyright/Acknowledgments
Xen is registered trademark of XenSource Inc
paramiko
library : By Robey Pointer
htmltextview.py : By Gustavo J. A. M.
Carneiro
TreeViewToolTip.py : By Daniel J. Popowich
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