Article number
000004577
Affected Versions
8.5
Source Hypervisor
VMware
Target Hypervisor
VMware

Number of helper VRA VMs (VRA-H) has increased following upgrade to Zerto 8.5

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Summary

Zerto 8.5 introduces a separation of the two traditional roles a recovery VRA VM has performed: executing VRA business logic and hosting the journal and recovery disks.

This separation increases the resiliency of the VRA and helps to isolate unexpected issues if they occur.

A VRA-H VM has no operating system, and does not consume any host CPU or memory. It only serves to host recovery or journal disks.

Root Cause

Prior to Zerto 8.5, the Virtual Replication Appliance (VRA) served two roles when used as a target for replication: it executed the code which conducted all the business logic of the VRA, and hosted the journal and recovery disks (max of 56 disks, plus the 4 OS disks). If more disks were needed for replication to a particular host, then a helper VRA was created to assist the VRA with the hosting of disks.

Starting in Zerto 8.5, only helper VRA VMs will host the journal and recovery disks. These VMs are named using the prefix VRA-H in vCenter inventory. Since only helper VRA VMs will host these disks, all disks currently attached to VRA VMs will be detached and then attached to a new or existing helper VRA.


 

Symptoms

The number of helper VRA VMs may increase following the upgrade of a site that is used as a recovery site to Zerto 8.5, depending on how many recovery and journal disks are hosted on each VRA. Each VRA-H VM can host up to 60 disks, since it is not running an OS.

For example:
Zerto 8.0 recovery site has 1 VRA VM with 4 OS disks, and it hosts 25 journal disks, and 31 recovery disks. It also has 1 VRA-H  hosting 10 journal disks.

Following upgrade to Zerto 8.5:
Zerto 8.5 recovery site has 1 VRA VM with 4 OS disks. It also has 2 VRA-H VMs; the first hosts 29 journal disks, and 31 recovery disks and the second hosts 6 journal disks.

Solution

This change is an intentionally designed part of the Zerto 8.5 product.