Use the -session (Multicast Image Set) mode command to take an image of one device and restore it to multiple other devices simultaneously over the network in a single operation.
IMPORTANT:For multicasting to work properly, the routers and switches on the network must have multicast features configured. Otherwise, multicast packets might not be routed properly.
For multicasting to work, each participating device must boot from an imaging boot media and run the ZENworks Imaging Engine in this mode, as explained below. The device from which the image is taken is called the master, and the devices that receive the image are called clients.
You can start the multicast session from the Imaging Server (see Initiating a Multicast Session from the ZENworks Imaging Server). If you start the session this way, you specify an image file for multicasting rather than a device as the session master. Otherwise, if you start the session from a client device, you can specify one of the session clients as the session master. In that case, an image of the session master’s hard drive is sent to the session clients. For more information, see Initiating a Multicast Session from Each Client.
To use the Help mode:
To display the ZENworks Imaging Engine menu, enter:
img
Click Imaging > Multicast Session.
This displays the Multicast Wizard.
Fill in the fields:
Session Name: Specify a unique name for the session.
Session Role: Select whether this participant is the master or a client.
One of the participants must be the master. It is the master who starts the session.
For Session Master Only: To specify additional options, click the check box for the Specify Additional Options field to display the Multicast Wizard dialog box containing the options, then fill in the fields:
Compression Level: Select one. Speed provides the fastest, but least compression and Size provides the most compression, but more slowly.
Automated Session: To enable the session, click the check box for the Enabled field. Specify the minimum number of clients to join (the default is 5) or the minimum number of minutes to transpire (the default is 5), or both, to provide the triggers for starting the session.
Click Next to continue.
The ZENworks Imaging Engine Menu is displayed with the Abort Session option. If you select this option to abort the multicast session, none of the clients queued for the session can be multicast-imaged because a master is required for a session to run.
If you enabled the session in Step 3, then when the number of clients or the timeout value is reached, the session begins.
If you did not enable the session in Step 3, you can click Start Session to enable it.
Using the imaging maintenance mode prompt, the following example explains the syntax and available parameters that you can use with the -session mode command:
img -session name -master [-clients=count] [-timeout=minutes] [-throttle=time] [-comp=comp_level][-retry=seconds]
or
img -session name -client
where the [...] brackets indicate optional commands.
You can abbreviate -session as -s and -master as -m.
For more information, see:
Table E-10 Session Mode Commands and Parameters
|
Parameter |
Specifies |
|---|---|
|
name |
The name of the multicast session. Each device joining the session uses the same value for this parameter. IMPORTANT:The name must be unique among concurrent multicast sessions. It is hashed by the ZENworks Imaging Engine to produce a Class D IP address for the multicast session. To facilitate troubleshooting (wire sniffing), all ZENworks imaging multicast addresses start with 231. For example, the session name mcast01 can produce the multicast address 231.139.79.72. |
|
‑master or ‑client |
Specifies that this device is the session master or a client. There can only be one master designated for the session. If you omit these parameters, the ZENworks Imaging Engine waits for a user at one of the devices to press m to designate that device as the master. You must then press s at the master device to start the session. |
|
‑clients=count |
The number of participating devices that must register in addition to the master before imaging begins. This option only applies to the device designated as the session master (where the ‑m parameter is used). The imaging session begins when: a) the final client has registered, b) you press s at the master device without waiting for all devices to register, or c) five minutes has passed since the last client has registered. If you omit this parameter, the ZENworks Imaging Engine waits for you to press s at the master device, which starts the imaging session. Thereafter, any devices attempting to register in the session are denied and queued for the next multicast session. |
|
‑timeout=minutes |
The number of minutes the master device waits (without reaching the required registered clients) after the last client has registered before starting the imaging process. This option only applies to devices designated as session masters (where the ‑m parameter is used). If you omit this parameter, the default timeout is 5 minutes. The imaging process does not start until: a) the client value is reached, b) the timeout value has transpired, or c) you press s at the master device. After that, any clients attempting to register are denied and queued for the next multicast session. |
|
‑throttle=time |
The number of micro-seconds to wait between master send packets. This is useful for throttling network traffic. |
|
-comp=comp_level |
The amount of compression used when creating the image. Specify any number from 0-9. 0 means no compression. 1 is the same as Optimize for Speed and is used by default if you do not specify this parameter; 6 is similar to Balanced; and, 9 is the same as Optimize for Space, which provides the slowest performance. |
|
-retry=seconds |
While resending the multicast packet, the number of seconds the master device waits before considering the client as disconnected (timed out). Configuring this parameter is useful when multicasting from a workstation that contains large directories. If you omit this parameter, the default timeout is 60 seconds. |
Table E-11 Session Mode Examples
|
Example |
Explanation |
|---|---|
|
img ‑session mcast01 |
Starts a multicast session named mcast01. Each successive device that issues this same command before imaging begins joins the session. Imaging doesn’t start until you press m on one of the devices to designate itself as the master, then press s to start the imaging. |
|
img ‑session mcast01 ‑m |
Starts a multicast session named mcast01 and designates this device as the master. Each successive device that issues img ‑session mcast01 before the imaging begins joins the mcast01 session as a client. Imaging doesn’t start until you press s on the master device. |
|
img ‑session mcast01 ‑master ‑clients=5 |
Starts a multicast session named mcast01. Each successive device that issues img ‑session mcast01 before imaging begins joins the mcast01 session as a client. Five other devices must register as clients before the session can begin, or five minutes must have elapsed since the last client registered. However, you can start the session from the master device without waiting for all devices to register by pressing s. |
|
img ‑session mcast01 ‑master ‑clients=5 ‑timeout=20 |
Starts a multicast session named mcast01. Each successive device that issues img ‑session mcast01 before the imaging begins joins the session. The session begins when either five other devices have registered as clients, or more than 20 minutes has elapsed since the last client registered. You can also press s to start the session at any time. |