You must upgrade certain components of your vSphere environment before you upgrade Site Recovery Manager.
Upgrade the components on the protected site before you upgrade the components on the recovery site. Upgrading the protected site first allows you to perform a disaster recovery on the recovery site if you encounter problems during the upgrade that render the protected site unusable. The exception is the ESXi hosts, which you can upgrade after you finish upgrading the other components on the protected and recovery sites.
If you configured bidirectional protection, in which each site acts as the recovery site for the virtual machines on the other site, upgrade the most critical of the sites first.
Upgrade the Platform Services Controller and all components of vCenter Server on the protected site.
If you use vSphere Replication, upgrade the vSphere Replication deployment on the protected site.
Upgrade Site Recovery Manager Server on the protected site.
If you use array-based replication, upgrade the storage replication adapters (SRA) on the protected site.
Upgrade the Platform Services Controller and all components of vCenter Server on the recovery site.
If you use vSphere Replication, upgrade the vSphere Replication deployment on the recovery site.
Upgrade Site Recovery Manager Server on the recovery site.
If you use array-based replication, upgrade the storage replication adapters (SRA) on the recovery site.
Verify the connection between the Site Recovery Manager sites.
Verify that your protection groups and recovery plans are still valid.
Upgrade ESXi Server on the recovery site.
Upgrade ESXi Server on the protected site.
Upgrade the virtual hardware and VMware Tools on the virtual machines on the ESXi hosts.