AP Image Preload

The AP image preload feature minimizes the downtime required for amanaged deviceupgrade by allowing the APs associated to thatmanaged deviceto download the new images before themanaged deviceactually starts running the new version.

This feature allows you to select the maximum number of APs that are allowed to preload the new software image at any one time, thereby reducing the possibility that themanaged devicemay get overloaded or that network traffic may be impacted by all APs on themanaged deviceattempting to download a new image at once.

APs能继续正常运行时downloading their new software version. When the download completes, the AP sends a message to themanaged device, informing it that the AP has either successfully downloaded the new software version, or that the preload has failed for some reason. If the download fails, the AP will retry the download after a brief waiting period.

You can allow every AP on amanaged deviceto preload a new software version, or also create a custom list of AP groups or individual APs that can use this feature. If a new AP associates to themanaged devicewhile the AP image download feature is active, themanaged devicewill check that AP’s name and group to see if it appears in the preload list. If an AP is on the list, (and does not already have the specified image in its Flash memory) that AP will start preloading its image.

Once a software version has been downloaded, another version cannot be downloaded until the AP reboots.

This section provides information on the following topics:

Enable and Configure AP Image Preload

Use the following procedures to enable and configure the AP Image Preload feature using the WebUI orCLICommand-Line Interface. A console interface with a command line shell that allows users to execute text input as commands and convert these commands to appropriate functions..

In the WebUI

1.To enable AP Image preload, navigate toMaintenance > Software Managementin theManaged Networknode hierarchy. Select thecontrollersthat require upgrade from theControllers/Clusterstable.

2.To enable AP Image preload for a specificmanaged device, select themanaged deviceand then navigate toMaintenance > Software Management.

3.SelectPreload software on access pointsinInstallation Settings.

In the CLI

To configure the AP image preload feature using the command-line interface, enter the following commands:

ap image-preload

activate all-aps|specific-aps

add {ap-group | ap-name }

取消

clear-all

delete {ap-group | ap-name }

[partition ]

[max-downloads ]

The parameters for this command are described inTable 1.

Table 1:AP Image Preload Configuration Parameters
Parameter	Description
activate	Issue theap image-preload activatecommand to activate this feature, allowing APs in the preload list to start downloading their new image from themanaged device.
all-aps	All APs will be allowed to pre download the image.
specific-aps	Only APs in the preload list will be allowed to preload the image.
add	Add individual APs or AP groups to the list of APs allowed to preload the image.
ap-group	Add a group of APs to the preload list.
ap-name	Add an individual AP to the preload list.
取消	Cancel the AP preload and clear the preload list. Any APs downloading a new image at the time this command is issued will continue to download the file.
clear-all	Clear all APs from the preload list.
delete	Delete an individual AP or AP group from the preload list. NOTE:This command may be issued before or after preloading is activated. If it is executed after preloading has already been activated, any APs downloading a new image at the time this command is issued will continue to download the file. APs that are still waiting to preload will be removed from the preload list.
ap-group	Remove the specified group of APs from the preload list
ap-name	Remove an individual AP from the preload list
partition	Specify the partition from which the APs should download their images. By default, the APs will preload images from themanaged device’s default boot partition.
max-downloads	Specify the maximum number of APs that can simultaneously download their image from themanaged device. The default value is ten APs.

View AP Preload Status

You can monitor the current preload status of APs using the image preload feature using theshow ap image-preload status summarycommand in the command-line interface.The output of thiscommand contains the following information:

Table 2:AP Image Preload Status Settings
Column	Description
AP Image Preload State/Count	These two columns list the different possible preload states for APs eligible to preload a new software image, and the total number of APs in each state. Preloaded: Number of APs that have finished preloaded a new software image. Preloading: Number of APs that are currently downloading the new image. Waiting: Number of APs that are waiting to start preloading the new image from themanaged device.
Count	This column lists the number of eligible APs currently in each preload state.
AP Name	Name of an AP eligible to preload a new software image.
AP Group	AP group of an AP eligible to preload a new software image.
美联社IP	IP address of the AP.
AP Type	AP model type.
Preload State	Current preload state for the AP Preloaded: The AP is finished preloading a new software image. Preloading:美联社目前下载the new image. Waiting: The AP is waiting to start preloading the new image from themanaged device.
Start Time	Time the AP starting preloading an image.
End Time	Time the AP completed the image preload.
Failure Count	Number of times that the AP failed to preload the new image.
Failure Reason	In the event of an image preload failure, this column will display the reason that the image download failed.

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