Upgrading a Single-Node PPDM with Custom Certificates and Shared DD
A financial services firm runs a single-node PPDM 19.x appliance on a VMware VM. It protects 280 TB of Oracle, SQL, and VMware workloads to a DD9400, with replication to a secondary DD. The platform team must upgrade to a newer 19.x release within a four-hour maintenance window. Constraints: external LDAP/AD integration, custom CA-signed web certificates, NTP source moved to a new stratum-1 server last week, and the DD pair is shared with a legacy Avamar environment. The backup window is 24x7 except for a two-hour application freeze. A previous upgrade attempt failed at precheck because the vCenter service account password had expired. The business requires no data loss and a tested fallback, but the VM cannot be cloned because of a storage policy. The team asks for a go/no-go checklist, upgrade order, and evidence to collect.
1. Build the go/no-go precheck list and identify the conditions that must stop the upgrade.
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Do not approve based only on the earlier password fix. Prechecks: confirm the target release, DD9400/DDOS, vCenter, ESXi, and Avamar coexistence in the support matrix; verify the LDAP/AD bind account is not expired and that time skew against the new NTP server is within tolerance; validate the custom CA chain, private key, and certificate expiry; confirm DD replication is healthy and no Avamar operation is active; check free capacity for upgrade artifacts and logs; verify no backup or restore is running; and confirm a recent configuration backup exists. Because the VM cannot be cloned, require a documented configuration export and a tested rebuild procedure, not an assumed snapshot rollback. Stop if certificate, NTP, or LDAP checks fail, because authentication, replication, and policy operations can fail after upgrade. Also stop if the four-hour window cannot include validation and a canary restore.
2. State the upgrade order and the post-upgrade validation sequence.
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Freeze backups, record active sessions, place DD replication on hold if the procedure allows, export the PPDM configuration, and capture the current state. Upgrade supporting components only if the compatibility matrix requires it; otherwise upgrade PPDM first, then vProxy/cProxy and DDOS in the prescribed order. Preserve LDAP and custom certificates through the upgrade; reapply them only if the upgrade resets them. After reboot, validate UI/API access, LDAP login, certificate chain, NTP offset, asset discovery, DD connectivity, and a small VM backup and restore. Then resume replication and production policies. Use a canary VM before Oracle or SQL. Keep the old appliance state offline until validation completes. If a precheck fails during the window, stop and roll back rather than starting production jobs.
3. Explain how the lack of a VM clone changes the fallback plan and what evidence proves readiness.
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Without a clone, fallback is rebuild plus restore from configuration export and re-registration of assets, not an instant revert. That raises risk and makes the rebuild runbook mandatory. It must include hostname/IP, DNS, certificates, LDAP bind, DD credentials, vProxy registration, and policy recreation. Test the rebuild path or at least a tabletop with measured steps; if it cannot fit the four-hour window, defer the upgrade or obtain a storage snapshot. Evidence to retain: precheck report, configuration export checksum, LDAP test result, certificate chain validation, NTP offset, DD replication status, canary backup and restore logs, and post-upgrade policy compliance report. A named approver should accept the residual risk if no clone is available.