System Requirements for Live Sync I/O

This topic summarizes requirements for Live Sync I/O.

To avoid delays in replication, implement the following best practices:

  • Use a low latency network.

  • Provide enough cache space and a fast storage connection to the cache on the access node (VSA proxy) at the source site.

  • Provide a fast storage connection to the RP Store.

  • Provide enough storage for the RP Store.

  • Timestamps must be synchronized between access nodes and ESXi hosts.

Hypervisor Support

vCenter and ESXi Requirements

  • vCenter Server version: 6.5

  • ESXi memory requirement for each VM: 100MB

  • On the ESX cluster, vSphere High Availability (vSphere HA) must be configured and vSphere Distributed Resource Scheduler (DRS) must be enabled.


  • Two access nodes (VSA proxies): One at the source site and one at the destination site.

  • MediaAgent should be present on the destination access node.

  • Low latency network between the access nodes, preferably 10 Gigabit Ethernet, depending upon I/O loads.

  • The destination requires a fast storage connection to the Recovery Point Store (RP Store).

Virtual Machine Disks

Before configuring a source VM for Live Sync I/O, ensure that the VM storage policy in vSphere is set to Datastore Default for all disks.

Access Node Operating Systems

You can deploy access nodes (VSA proxies) on physical or virtual machines running the following operating systems:

  • Microsoft Windows Server 2016

  • Microsoft Windows Server 2012 R2 x64 Editions

  • Microsoft Windows Server 2012 x64 Editions

  • Microsoft Windows Server 2008 R2 x64 Editions


Linux access nodes are not supported.

Plug-In Installation or Upgrade Requirements

VMware vCenter Server Privileges

  • Ensure that vCenter permissions are configured correctly as described in Permissions for Custom User Accounts.

  • The VMware vCenter Server user account used to install plug-ins must have administrator privileges for installation or upgrade.

Acceptance Level

  • For each ESX host, ensure that the acceptance level is CommunitySupported. Other acceptance levels are not supported.

Licenses and Features Enabled

  • vSphere Enterprise Plus license is required to support continuous replication.

  • During installation or upgrade of the Commvault plug-in, ESX servers go into maintenance mode, which requires that vSphere High Availability (vSphere HA) is configured and vSphere Distributed Resource Scheduler (DRS) is enabled.

  • Plug-ins must be part of protected and replicated data centers (ESX clusters).

Source Access Node Cache Requirement

  • Cache location: Job Results directory

Network Bandwidth

Provide network bandwidth based on the estimated I/O speed. For example:

  • Protected VMs: 10

  • Rate at which each VM performs I/O: 100 MB/s

  • Preferred Network Speed: 1000 MB/s

Preferred Recovery Point Store (RP Store) Requirement

Size the RP Store based on I/O throughput and RP Retention criteria. For example:

  • RP Store I/O throughput: 100 MB/s

  • Total Retention Time (hours): 5 Hrs

  • RP Store size: 1800000 MB (1.72 TB)

Firewall Port Requirements

For environments that include a firewall, open the following ports:

  • For ESXi servers on the source site, open port 38403.

  • For ESXi servers on the destination site, open port 38404.

These ports are used by the BLR service to communicate with VAIO daemons.