Lenovo ThinkAgile CP Part Replacement And Component Maintenance Procedures page 84

available, pick a new range for this network (for example, 10.65.0.0/24) since it is internal to the network
stack.
• Obtain the hypervisor network settings (DHCP_RANGE_START, DHCP_RANGE_END, DHCP_ROUTER_
IP, DHCP_NETMASK, PRIMARY_DNS, SECONDARY_DNS) from the primary interconnect. This
information comes from the configuration file and is located in the configuration spreadsheet provided
before installation.
Important: This procedure can be performed only under supervision of or with help from Lenovo Support.
Execution: On hardware only
Performed by: Lenovo Support
Background: Dual interconnect configuration (DS-V3) is active-active. A DHCP server runs on both
interconnect switches, and the DHCP lease file is synchronized between the two interconnect. In the event
that the primary interconnect switch goes down, the DHCP server on the secondary interconnect begins to
service IP requests.
Attention:
• This only works on the Hypervisor Network. DHCP High Availability does not function on the Management
Network.
• This procedure requires physical intervention on the hardware.
Note: Ensure that the primary interconnect is shut down when running these steps. Having two DHCP
servers in split-brain configuration causes severe disruptions on the stack network.
To make the secondary interconnect switch into the primary interconnect, follow these steps:
Step 1. (Optional) If the primary interconnect is not shut down, sign in to the primary interconnect in
Support Mode or, if at the data center, using a method provided by the manufacturer. The
username is admin and the password is the one you set during installation.
Step 2. (Optional) If the primary interconnect is not shut down, run the following commands on the primary
interconnect to disable the DHCP service:
> > s s u u d d o o s s e e r r v v i i c c e e i i s s c c - - d d h h c c p p - - s s e e r r v v e e r r s s t t o o p p
> > s s u u d d o o s s e e r r v v i i c c e e i i s s c c - - d d h h c c p p - - s s e e r r v v e e r r d d i i s s a a b b l l e e
Step 3. Sign into the second interconnect using the same procedure.
Edit /etc/tacp/tacp_switch_resource.sh with the hypervisor network settings (DHCP_
a.
RANGE_START, DHCP_RANGE_END, DHCP_ROUTER_IP, DHCP_NETMASK, PRIMARY_
DNS, SECONDARY_DNS) from the primary interconnect.
Copy the backed-up lease database /var/lib/dhcp/dhcpd.leases from the primary
b.
interconnect to the corresponding location on the secondary interconnect, if available.
Note: If the backed-up lease database is not available, you need to configure the secondary
interconnect as new. ThinkAgile Advantage assists you with this procedure.
Run the following command to create /etc/dhcp/vlan-mgmt.conf with the hardware
c.
management network settings (BMC_ DHCP_START, BMC_DHCP_END, BMC_ROUTER_IP,
BMC_PREFIX) from the primary interconnect.
> > s s u u d d o o / / u u s s r r / / s s h h a a r r e e / / t t a a c c p p / / r r e e s s e e t t _ _ b b m m c c _ _ n n e e t t w w o o r r k k . . s s h h
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ThinkAgile CP Part Replacement and Component Maintenance Procedures