Flow Control Policy
Flowcontrol policies determine whether the uplink Ethernet ports in a Cisco UCS domain send and receive
IEEE802.3x pauseframes when the receivebuffer for a port fills. These pause frames request that the
transmittingport stop sendingdata fora fewmilliseconds until thebuffer clears.
Forflow control to work between a LAN port and an uplink Ethernet port, you must enable the corresponding
receiveand send flow controlparameters for both ports. For Cisco UCS, the flow control policies configure
theseparameters.
Whenyou enable the send function, the uplink Ethernet port sends a pause request to the network port if the
incomingpacket rate becomes too high. The pause remains in effect for a few milliseconds before traffic is
resetto normal levels. If you enable the receive function, the uplink Ethernet port honors all pause requests
fromthe network port. All traffic is halted on that uplink port until the network port cancels the pause request.
Becauseyou assign the flow control policy to the port, changes to the policy have an immediate effect on how
theport reacts to a pause frame or a full receive buffer.
Maintenance Policy
Amaintenance policy determines how Cisco UCS Manager reacts when a change that requires a server reboot
ismade to a service profile associated with a server or to an updating service profile bound to one or more
serviceprofiles.
Themaintenance policy specifies how Cisco UCS Manager deploys the service profile changes. The deployment
canoccur in one of the following ways:
• Immediately
• When acknowledged by a user with admin privileges
• Automatically at the time specified in the schedule
Ifthe maintenance policy is configured to deploy the change during a scheduled maintenance window, the
policymust include a validschedule. The scheduledeploys the changes inthe firstavailable maintenance
window.
Scrub Policy
Thispolicy determines what happens to local data and to the BIOS settings on a server during the discovery
processand when the server is disassociated from a service profile. Depending upon how you configure a
scrubpolicy, the following can occur at those times:
DiskScrub
Oneof thefollowing occurs to the data on any localdrives on disassociation:
• If enabled, destroys all data on any local drives
• If disabled, preserves all data on any local drives, including local storage configuration
Cisco UCS Manager GUI Configuration Guide, Release 2.0
OL-25712-04 29
Server Architecture and Connectivity