When a new VDP appliance is created, the destination datastore begins to fill rapidly on each new virtual machine backup added. This is due to the fact that each virtual machine being backed up contains unique data. To help reduce the amount of unique data being backed up, and therefore reduce the rate of growth on initial virtual machine backups, it is best to group similar backups together. For example, the initial backup of two Windows 2008 virtual machines requires less destination datastore space as similar data results in better deduplication efficiency. The initial backup of a Windows 2008 virtual machine and a Linux virtual machine would likely require more destination datastore space as there are unlikely to be similar data. After the initial backups, the VDP appliance backs up less unique data during subsequent backups. This is due to the Changed Block Tracking functionality in vSphere and deduplication in the VDP appliance.
However, if you are unsure of destination datastore capacity requirements, it is better to deploy a larger VDP appliance. When the appliance has been deployed, additional capacity cannot be added.
Q: Is DNS required for VDP to work?
Yes. Full DNS resolution (shortname, FQDN, forward, and reverse) must be configured correctly for VDP to work. If there are DNS issues, VDP operations, such as backups, are impacted. A DNS host record for a VDP appliance should be created prior to deploying the VDP appliance.
Q: What’s a blackout window?
The blackout window is the portion of each day reserved for performing server maintenance activities, such as garbage collection, which require unrestricted access to the server. Garbage collection deletes the orphaned chunks of data that are no longer referenced within any backups stored on the system. By default, the blackout window begins at 8 AM local server time and continues uninterrupted for three hours until 11 AM that same morning. This can be customized.
Note: No backup or administrative activities are allowed during the blackout window, however restores can be performed.
Q: What’s the difference between the blackout window and the maintenance window?
The maintenance window is the portion of each day reserved for performing routine server maintenance activities such as integrity check validation, whereas the blackout window performs server maintenance which requires unrestricted access.
Note: Backups can be initiated during the maintenance window, but doing so impacts both the backup and maintenance activities.
Q: Can I set a blackout window to 0?
No. A blackout window is required. It is possible to customize when the blackout window occurs.
Q: What are checkpoints and when would I be required to use them?
A checkpoint is a system-wide backup taken for the express purpose of assisting with disaster recovery. Checkpoints are scheduled and created once a day during the maintenance window. VDP stores two checkpoints (one validated and one not validated).
Q: What happens if rollback doesn’t work?
If a rollback fails, then deployment of a new VDP appliance is required. Migrating configuration and backup data from one appliance to another is not supported in VDP 5.1, this functionality was added in VDP 5.5.
Q: If I create a backup job during the backup window, will it start backing up immediately?
No. The backup jobs are scanned at the start of the backup window. If the job does not exist at this time, it will not run. It will be scheduled to automatically start at the next backup window. However, you can manually start a backup job during the backup window.
Q: Can I schedule backup jobs to run at different times?
There is only one backup window per VDP appliance. The backup jobs are run during this backup window. It is not possible to create separate backup windows for each backup job. When creating a backup job, it is possible to define how often the backup runs. For example, daily, weekly, or monthly.
Q: How many backups can run in parallel?
Each VDP appliance can simultaneously back up a maximum of eight virtual machines.
Q: Am I able to do a file-level restore (FLR) of my Linux virtual machines?
The file-level restore is web-based, so a supported web browser is required. At the time of writing, a command-line FLR is not available.
Q: Are there any prerequisites to use the FLR?
A web browser is required to connect to the VDP appliance. VMware Tools must also be running within the virtual machine where the file-level restore is occurring.
Q: Am I able to restore a backed-up virtual machine’s virtual disk to different datastores?
It is possible to restore a virtual machine to a datastore other than the original. However, all files that make up the restored virtual machine are restored to the same datastore.
Q: Can I perform a Restore Rehearsal, as I used to do in VDR?