Observe the following best practices when using the NetWorker VMware Protection solution.
For best practices specifically related to deployment of the VMware Backup Appliance, the section VMware Backup Appliances best practices on page 30 provides details.
l Ensure that the NetWorker server and storage node are at the same version, and that the VMware Backup Appliance you deploy is compatible with this version, for example, NetWorker 8.2 SP1 with OVA 1.1.1.50.
l Use Hotadd transport mode for faster backups and restores and less exposure to network routing, firewall, and SSL certificate issues. To support Hotadd mode, deploy the VMware Backup appliance on an ESXi host that has a path to the storage holding
the virtual disk(s) being backed up. In environments using the older VMFSv3 format datastore, deploy the proxy on the datastore with the largest block size.
Note
Hotadd mode requires VMware hardware version 7 or later. Ensure all VMs being backed up are using VM hardware version 7 at a minimum.
For sites that contain a large number of VMs that do not support Hotadd
requirements, NBD backups will be used. This can cause congestion on the ESXi host management network. Plan your backup network carefully for large scale NBD installs. You may consider:
n Set up Management network redundancy
n Set up backup network to ESXi for NBD
n Go to http://www.vmware.com/files/pdf/techpaper/vmw-vsphere-high-availability.pdf to learn how to set up storage heartbeats.
l Avoid deploying VMs with IDE virtual disks; using IDE virtual disks degrades backup performance. Use SCSI virtual disks instead whenever possible.
Note
You cannot use hotadd mode with IDE Virtual disks and therefore backup of these disks will be performed using NBD mode.
l During policy configuration, assign clients to a policy based on logical grouping to allow for better scheduling of backups that will help you avoid resource contention and create more organized logs for review.
l EMC recommends performing regular checkpoint backups to protect the VMware metadata in your environment. You can schedule daily checkpoint discover and checkpoint backup actions for a VMware Protection Policy within NMC, as outlined in the section Setup and configure policies in NMC on page 67.
l When planning for backups, ensure that NetWorker VMware Protection supports the disk types. Currently, NetWorker VMware Protection does not support the following disk types:
n Independent (persistent and non-persistent)
n RDM Independent - Virtual Compatibility Mode
n RDM Physical Compatibility Mode
l Enabling Change Block Tracking (CBT) allows you to achieve faster incremental backup performance. The default VMware Backup Appliance configuration has a threshold of 25% change per client, which means that if the particular VM has changed more than 25% since the last backup, a level full backup is performed. In order to support Changed Block Tracking (CBT):
n Ensure that all VMs run VMware hardware version 7 or higher.
n If you add a disk or dynamically expand a disk on a VM, you must take a new full backup for CBT to function.
For Incremental backups with CBT, remove any existing snapshots of a VM before adding to the VMware Backup Appliance.
l When backing up thin-provisioned VMs or disks for VMs on NFS datastores, note that thin provisioning is not preserved during recovery for NFS datastores. The VMware knowledgebase article 1035096 at http://kb.vmware.com/kb/1035096 provides more information.
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l Install VMware Tools on each VM that you want to back up using the EMC Backup and Recovery user interface in the vSphere Web Client. VMware Tools adds additional backup capability that quiesces certain processes on the guest OS prior to backup.
VMware Tools is also required for some features used in File Level Restore.
l For VDDK backups, install the latest VDDK kit:
n HF222276 for the NetWorker 8.1 VMware Backup Appliance
n HF222268 for the NetWorker 8.1 SP1 and later VMware Backup Appliance
n HF207384 for the NetWorker 8.2 and later VMware Backup Appliance
l Conflicting vSphere Web Client plug-ins can cause unexpected behavior with the EMC Backup and Recovery user interface in the vSphere Web Client. Examples include the VDP plug-in, and the HP Insight Manager plug-in. The knowledgebase article at http://kb.vmware.com/kb/1025360 provides instructions to remove conflicting plugins.
l EMC recommends setting an appropriate NetWorker server/storage parallelism value according to the available resources to reduce queuing. For example, a VMware Backup Appliance with 5 external proxies and clones requires more than 64 parallel sessions. Therefore, setting the parallelism for the NetWorker server to 128 or higher (while also setting the server with 32+ GB memory and 8+ CPUs) will suit such an environment. The EMC NetWorker Performance Optimization Planning Guide provides more details.
If you require a larger number of parallel image backups, also consider setting the maximum number of vCenter SOAP sessions to larger value. Note that this requires careful planning and additional resources on the vCenter Server You can configure this by modifying the following line in the vCenter vpxd.cfg file:
<vmacore><soap><maxSessionCount> N </maxSessionCount></
soap></vmacore>
This applies specifically to SDK sessions as opposed to VI client sessions:
l Each VM backup to a Data Domain system consumes more than one session on the Data Domain device. The default device configuration is target sessions=6 and max session=60, however EMC recommends that you configure additional devices for more than 10 parallel backups.
l VMs with extremely high IO may face hangs during consolidation due to the ESXi forced operation called synchronous consolidate. Plan your backups of such VMs according to the amount of workload on the VM.
l When working with the vCenter database either directly or by using scripts, do not change the name attribute for the vmfolder object. The knowledgebase article at https://support.emc.com/kb/190755 provides more information.
l Setting up multiple devices locally on the NetWorker server can lead to resource contention. Large VMware environments are observed to have more stability when most backup devices are set up on a remote storage node.
When you mount a backup or clone pool volumes on a remote storage node, then modify the properties for the VMware Backup Appliance to add these storage node names under the Globals (2 of 2) tab of the NetWorker Client Properties window in NMC.
l Resource contention can occur at various points during the backup cycle. Running larger savegroups and policies often cause issues due to contention of resources that impact all running operations. Adjust your resources and times for other larger savegroups/policies to avoid overlaps, thereby avoiding resource contention.
For example, if you set up a policy where every day at 10pm two policies called 'Bronze1' and 'Bronze2' with 400 clients each start writing to a pool named 'Bronze' which is configured for just one device on NetWorker, the long wait for device
availability may cause unexpected delays or timeouts. To fix this, set the policy start times 4 hours apart and add more devices to allow for stable backups.