Upgrade a multisite cluster Upgrade up to three data centers in an environment, each having up to two MSM VMs. These MSM VMs can each be associated with up to two Core VMs. About this task The following figure shows multisite cluster data center environment: Upgrade the VMs in each data center starting with the data center containing the MSM VM acting as the Cassandra seed node. The Core VMs can be upgraded across data centers before the MSM VM upgrades to minimize the time between upgrading the MSM VM. Once the upgrade process begins, do not: Add any Core VMs to any MSM VMs in the cluster. Join any additional MSM VMs to the MSM VM cluster. After an MSM VM cluster is upgraded, exceptions may display in the /opt/vce/multivbmgmt/logs/CollectionManager.log until all MSM VMs are upgraded. Collections may fail on MSM VMs until they are upgraded. Until both data centers are upgraded, an MSM VM upgrade in one data center impacts collections by MSM VMs running in the other data center. Child TopicsStart a Core VM upgradeRun VxBlock-Central_core_upgrade-<buildnumber>.vce to upgrade the Core VM. Verify a Core VM upgradeAfter upgrading, verify the correct version of the Core VM is installed. Start the MSP VM upgrade Execute VxBlock-Central_msp_upgrade--<buildnumber>.vce to upgrade. Verify the MSP VM upgradeVerify the status of the MSP VM. Identify the MSM VM acting as the Cassandra seed node Find the seed node to determine the MSM VM to start the upgrade. If the MSM VM cluster spans multiple data centers, perform the upgrade on each data center separately. Start an MSM VM upgradeStart the MSM VM upgrade file on the MSM VM. Update the MSM credential manager service If the root or VxBlock Central user password has been changed on the Core VM, update the MSM credential manager service with the password. Verify the MSM VM upgrade After completing the upgrade process, use the VxBlock Central dashboard to verify that the version number of the MSM corresponds to the version that you installed. Parent topic VxBlock Central upgrade overviewThe VxBlock Central upgrade can be performed for the Core VM, MSM VM, and MSP VM in single site or multisite clusters.