Installing Virtual Replication Appliances on Hosts in Cloud Sites

Zerto recommends installing a VRA on every host in every cloud site.
If virtual machines protected in the cloud are moved from one host in a cluster to another host in the cluster there is always a VRA to protect the moved virtual machines.
If you are protecting a vApp, you must install a VRA on every host in the cluster on both the protected and recovery sites and ensure that DRS is enabled for these clusters.

VRA Installation Requirements

Setting up Routing

Installing a Zerto Virtual Replication Appliance (VRA) on a Host

VRA Installation Requirements

To install a VRA you require the following:

12.5GB datastore space.
At least 1GB of reserved memory.
The ESX/ESXi version must be in accordance with supported ESX/ESXi versions in the Interoperability Matrix, and Ports 22 and 443 must be enabled on the host during the installation.

You must also know the following information to install a VRA:

If the ESXi version is 5.5 or higher and the VRA should connect to the host with user credentials, or if the ESXi version is lower than 5.5 ( 5.x), the password to access the host root account.
Note: For ESXi versions 5.5 or higher, by default the VRA connects to the host with a vSphere Installation Bundle, VIB. Therefore, it is not necessary to enter the password used to access the host root account.
The storage the VRA will use and the local network used by the host.
The network settings to access the peer site; either the default gateway or the IP address, subnet mask, and gateway.
Note: When the gateway is not required, you can specify 0.0.0.0 as the gateway, for example when performing self replication.
If a static IP is used, which is the Zerto recommendation, instead of DHCP, the IP address, subnet mask, and default gateway to be used by the VRA.
Note: In a non-production environment it is often convenient to use DHCP to allocate an IP to the VRA. In a production environment this is not recommended. For example, if the DHCP server changes the IP allocation on a reboot, the VRA does not handle the change.
Note: For the duration of the installation of the VRA, the Zerto Virtual Manager enables SSH in the vCenter Server.

If the peer site VRAs are not on the default gateway, you must set up routing to enable the VRAs on this site to communicate with the peer site VRAs.

Setting up Routing

To set up routing:

1. In the Zerto Cloud Manager Sites tab, click a site name.
2. In the Zerto Virtual Manager GUI that opens, click the Setup tab.
3. Select MORE > Paired Site Routing.

The Configure Paired Site Routing dialog is displayed.

The IP address, subnet mask, and gateway to access the peer site VRAs when access to the peer site VRAs is not via the default gateway.

Enable Paired Site Routing: When checked, enables paired site routing.
Address: The IP address of the next hop at the local site, the router, or gateway address that is used to access the peer site network.
Subnet Mask: The subnet mask for the peer site network.
Gateway: The gateway for the peer site network.

These access details are used to access the VRAs on the peer site.

The settings in the Configure Paired Site Routing dialog apply to all VRAs installed after the information is saved. Any existing VRA is not affected and access to these VRAs continues via the default gateway. If the default gateway stops being used, you must reinstall the VRAs that were installed before setting up paired site routing.

Installing a Zerto Virtual Replication Appliance (VRA) on a Host

To install a Zerto Virtual Replication Appliance (VRA) on a host:

1. In the Zerto Cloud Manager Sites tab, click a site name.
2. In the Zerto Virtual Manager GUI that opens, in the Setup tab, select a host that needs a VRA and click NEW VRA.

The Configure and Install VRA dialog is displayed. The dialog displayed depends on the ESX/i version:

ESXi versions from 5.5 ESXi versions before version 5.5
Note: If you selected a cluster or multiple hosts, the VRA is installed on the first host in the displayed list.

To configure and install Zerto Virtual Replication Appliances (VRAs) on ESX/ESXi hosts:

3. Specify the following Host Details:
Host: The host on which the VRA is installed. The drop-down displays the hosts that do not have a VRA installed, with the selected host displayed by default.

(vSphere only) From ESXi 5.5, by default, Zerto Virtual Manager creates a .VIB (vSphere Installation Bundle) which is used to set up a secure communication channel to the host. The .VIB is installed on the host when the VRA is installed. When using VIB:

The user does not enter a password.
Once a day, Zerto Virtual Manager checks that the VRA and host can connect. If the connection fails, Zerto Virtual Manager re-initiates the connection automatically and logs it.

(vSphere only) For ESX/i versions earlier than 5.5, when using a password, Zerto Virtual Manager connects to the host using the root password. Once a day, Zerto Virtual Manager checks that the password is valid. If the password was changed, an alert is issued, requesting the user enter the new password.

Use credentials to connect to host: When unchecked, the Zerto Virtual Manager uses VIB to set up a secure communication channel to the host. This field is only relevant for ESXi 5.5 and later.
Host Root Password: When the VRA should connect to the host with a password, check Use credential to connect to host and enter the root user password used to access the host. When the box on the right side is checked, the password is displayed in plain text. This field is only relevant for ESXi 5.x hosts.
Datastore: The datastore that contains the OS disks of the VRA VM. You can install more than one VRA on the same datastore.
Network: The network used to access the VRA.
VRA RAM: The amount of memory to allocate to the VRA. The amount determines the maximum buffer size for the VRA for buffering IOs written by the protected virtual machines, before the writes are sent over the network to the recovery VRA. The recovery VRA also buffers the incoming IOs until they are written to the journal. If a buffer becomes full, a Bitmap Sync is performed after space is freed up in the buffer. For details, refer to Zerto Scale and Benchmarking Guidelines.
VRA Bandwidth Group: Choose the VRA Bandwidth Group from the dropdown list. To create a new VRA group, type in the name of the new group and click CREATE. You can then choose the new group from the dropdown list.

You group VRAs together when VRAs use different networks so they can be grouped by network, for example when the protected and recovery sites are managed by the same vCenter Server and you want to replicate from the branch site to the main site. Within a group the priority assigned to a VPG dictates the bandwidth used and is applicable within a group and not between groups. Thus, a VPG with a high priority is allocated bandwidth before VPGs with lower priorities. VPGs that are on VRAs with different VRA groups, for example, VPG1 on VRA1 in group1 and VPG2 on VRA2 in group2, do not affect each other, as the priority is relevant only within each group.

4. Specify the following VRA Network Details:
Configuration: Either have the IP address allocated via a static IP address or a DHCP server. If you select the Static option, which is the recommended option, enter the following:
Address: The IP address for the VRA.
Subnet Mask: The subnet mask for the network. The default value is 255.255.255.0.
Default Gateway: The default gateway for the network.
5. Click INSTALL.

The VRA installation starts and the status is displayed in the TASKS popup dialog in the status bar and under MONITORING > TASKS.

The VRA displayed name, and DNS name, is Z-VRA-hostname. If a virtual machine with this name exists, for example when a previous VRA was not deleted, the VRA name has a number appended to it.

6. Add a VRA to every host that hosts virtual machines for which you want replication.

Zerto recommends installing a VRA on every listed host.

An alert is issued after the first VRA is installed in a cluster that tells you to install a VRA on the other hosts in the cluster. The alert is automatically removed when all the hosts in the cluster have VRAs installed.

Return to the Zerto Cloud Manager Sites tab and click the next site name in the list to display the site tab with nested tabs and install the VRAs for this site. Repeat this procedure for every site in the Zerto Cloud Manager.
A VRA can manage a maximum of 1500 volumes, whether these are volumes being protected or recovered.
Note: VRAs are configured and managed by the Zerto Virtual Manager. You cannot take snapshots of VRAs as snapshots cause operational problems for the VRAs.