Active Directory/Documentation/WDS/Performance

WDS utilizes network and server hardware in many configuration-dependent ways. This page attempts to document some of those configuration scenarios and what kind of performance users can expect.

PXE

In the WDS imaging process, the first action is taken by a computer PXE-booting and transferring, via trivial file transfer protocol (TFTP), a boot image from the server to the client. These boot images range between 350MB and 850MB in size, with the more commonly-used boot images being about 380MB. In the campus environment, PXE-booting can connect you to one of three different TFTP servers:

• PXE-all: ? MB/min
• WDS-Main: 930 MB/min
• WDS-Centennial: ? MB/min

Note that TFTP transfer times can vary widely due to network conditions, BIOS support, NIC drivers, and other reasons. These numbers should be considered a better than average guideline.

Unicast Transfers

Unicast is a network term referring to transfers that are processed by exactly one computer. At present, all WDS imaging activities are performed in this way.

• One image, one client: ? MB/min
• One image, two clients: ? MB/min/client
• One image, 31 clients: 150-190 MB/min/client

Multicast Transfers

Multicast is a network term referring to transfers that are processed by one or more computers. Multicasting is generally used when imaging computer labs. At present, WDS multicasting is disabled by the campus network authority, ComTech, so no performance measurements can be taken.

Performance Tests

There have been numerous informal performance tests of the WDS service. Formal tests have been listed below:

• 7/10/2009, Sullivan Lab: 31 computers