Site Recovery Manager (SRM) Storage Replication Adapter (SRA) Issues
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Site Recovery Manager (SRM) Storage Replication Adapter (SRA) Issues

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Article ID: 312663

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Updated On:

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VMware Live Recovery

Issue/Introduction


Often times it can be confusing when deciding where to seek assistance when administrators encounter storage related issues with Site Recovery Manager, especially with Array Pairing, Protection Group creation/management, and Recovery Plan operations and failovers.

The goal of this KB article is to assist with knowing how to navigate this between vendors.

An SRA is a program that an array vendor provides that enables Site Recovery Manager to work with a specific kind of array. reference 

If you use more than one type of storage array, you must install the SRA for each type of array on both of the Site Recovery Manager Server [...]


Symptoms:


Site Recovery Manager (SRM) is an orchestrator to register VM's into Protection Groups and Recovery Plans. The storage vendors Storage Replication Adapter shares with SRM a list of Array Pairs with device pairs.

The Storage Array is responsible for

  • LUN snapshots are not unmounted at one site
  • Promote and Demote of the datastores between the sites does not complete or fail
  • Array Based Replication is not copying data from one site to the other (Replication is broken)
  • The Test Failover doesn't create or delete copies of the replica LUNs on the target site
  • Reprotect is grayed-out after failover which means the workflow reverseReplication on the storage array has not completed or the Storage Replication Adapter did not pass the command request to SRM


Resolution


Array Based Replication is specific to the storage vendor and separate from the Site Recovery User Interface, although we do get information about replication (inquired through the SRA) in the SRM GUI. Site Recovery Manager has two options through the Storage Replication Adapter after selecting the Array Pairs, which are Discover Array Pairs or Discover Devices. Site Recovery User Interface does not manipulate any consistency groups or change device pairs states on the storage array directly. 
 

  1. In the vSphere Client or the vSphere Web Client, click Site Recovery > Open Site Recovery.
  2. On the Site Recovery home tab, select a site pair, and click View Details.
  3. On the Site Pair tab, click Configure > Array Based Replication > Array Pairs.
  4. Select an array pair and click Array Manager Pair > Discover Array Pairs to rescan the arrays, or Discover Devices to recompute the storage replicated devices.


When you select an array pair, the Array Pairs tab provides detailed information about all the storage devices in the array, including the local device name, the device it is paired with, the direction of replication, the protection group to which the device belongs, whether the datastore is local or remote, and replica pair identification for each replicated device. All of this data is gathered from the SRA via a discoveryArrays request, for example.

If you encounter an SRA issue, in any of the areas described above, it will be helpful to open a ticket with the Storage Vendor and seek the assistance from a trained SRA engineer. You can also make a likewise case with an SRM engineer at VMware to assist collaboratively. 

Storage Replication Adapters are software modules for Site Recovery Manager that are developed and supported by storage partners of VMware and are distributed here by VMware with the permission of the storage partners. Storage Replication Adapters have separate End User License Agreements (EULAs) that are included within these downloads. These sort of partnerships are no different than other aspects with vSphere, such as drivers, hardware, and so forth.
 

The VMware Compatibility Guide for Site Recovery Manager will help you to identify the Storage Replication Adapter that is certified to work with both your storage platform and Site Recovery Manager. The VMware Compatibility Guide is available at https://www.vmware.com/resources/compatibility/search.php?deviceCategory=sra
 

For more details about the Storage Replication Adapters and VMware vCenter Site Recovery Manager, please see the Site Recovery Manager EULA and documentation.

Any issues found with the vendor provided SRAs are handled by the corresponding vendor as described in the 3rd party support documentation at http://www.vmware.com/support/policies/ThirdParty.html.


Additional Information


Array Based Replication software on the array side, has the main function of establishing and maintaining LUN replication pairs. This is independent of SRM entirely and could be used solely on its own. SRM comes in as an orchestrator to direct (through the SRA) ABR software functions on replica pairs to be able to achieve an orchestrated failover, reverse replication, failback, DR tests, and so forth. 

Steps are from bottom to top in the diagram below

1. Array Based Replication (ABR) consists of having a production LUN (source) replicated/paired with a destination copy (replica) that is in a demoted state on the destination side.
2. Storage Replication Adapter (SRA) is the storage vendor specific software that is installed inside the SRM appliance.
3. In the Site Recovery UI - Add Array Pairs and select the VM's associated with the Device Pairs
4. In the Site Recovery UI -  Scan the device pairs by clicking on Discover Devices 
    Select an array pair and click Array Manager Pair  > Discover Array Pairs to rescan the arrays, or Discover Devices to recompute the storage devices and find/update replica pairs and their states.


 

Workflow of API between SRM and ABR

 

You can reconfigure the frequency Site Recovery Manager performs regular array scans by changing the storage.minDsGroupComputationInterval option in Advanced Settings in the Site Recovery UI. See Change Storage Settings.
 

Array Based Replication (ABR) uses command requests through the Storage Replication Adapter installed on the Site Recovery Manager (SRM). The command requests notifies a set of array operations from the storage array to SRM which steps have completed. 


Important: Please note that the command requests SRM provides for all Storage Replication Adapter vendors are the same commands sent to all storage adapters, owned by any supported vendor. The storage vendor is responsible for how their SRA reacts to these requests (or directives) based upon specifics to their replication software and array itself.

 

Workflow parameters for Array operations:
 

  • syncOnce –   requests immediate replication
  • querySyncStatus –   queries the status of a replication initiated by sync
  • OnceocheckTestFailoverStart*– validates environment and target devices for test failover readiness
  • testFailoverStart – creates writable temporary copies of the target devices 
  • testFailoverStop – deletes the temporary copies created by testFailoverStart
  • checkFailover*– validates environment and target devices for failover readiness
  • prepareFailover – makes source devices read-only and optionally takes a snapshot of the source devices in anticipation of a   failover
  • failover – promotes target devices by stopping replication for those devices and making them writable
  • prepareReverseReplication and reverseReplication - reverses array replication so that the original target array becomes the source array and vice versa
  • prepareRestoreReplication and restoreReplication -  restores array replication after failover.


SRM executes the following commands to discover replicated storage:
 

  • discoverArrays –   discover storage arrays configured for replication
  • discoverDevices –   discover devices on a   given storage array replicated to the specified target array

Example:
An array pair {00A, 00B}. The discoverDevices command from SRM will ask through the SRA for the list of device pairs it configured. From there we can find out what devices are relevant to the current environment and allow the admin to then setup Protection Groups for replica VMFS/RDM pairs.

 

Site A

Site B

DiscoverDeviceParameters
ArrayId 00A
PeerArrayId 00B

DiscoverDeviceParameters
ArrayId 00B
PeerArrayId 00A

 
  1. All Array Based Replication between the two sites is managed by the storage array. SRM does not replicate data.
  2. Site Recovery Manager relies on the Storage Replication Adapter (SRA) to communicate with the storage array for all completed steps.
  3. Each product (SRM and the storage array) have their own set of workflow parameters and do not manipulate or change the others configuration. 


If the problem is more of a datastore problem than a site recovery problem open a new support request for storage and collect ESXi host support bundles.  How to file a Support Request in Customer Connect https://kb.vmware.com/s/article/2006985


If skyline is installed and configured to monitor the system(s) check the storage health https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.monitoring.doc/GUID-612FD656-5C18-4F89-80A5-3A01E89E0FB6.html


If the storage is VMware vSAN check the health of the datastores https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.vsan-monitoring.doc/GUID-9504EECF-5946-49FB-86C6-8A4F977F5FC3.html

command line:  esxcli vsan cluster get  and esxcli vsan health any issues engage the VMware vSAN team. 


If the storage is a vmfs datastore, identify the disks used in SRA replication https://kb.vmware.com/s/article/1014953
Live on the system check the /var/run/logs/ directory for any storage errors. https://kb.vmware.com/s/article/2013160


Impact/Risks: