First, I will point out that it is not necessarily a bad thing to have production data and backup data living in together on the same storage platform (VSAN, in this case) as long as you have a another copy of this backup data located elsewhere. VSAN is quite resilient to issues such as the failure of a drive or a vSphere host, but that will not help when someone accidentally hits the Delete button. Having your backup data locally available enables rapid restores for situations such as data corruption inside of a VM or that inadvertent deletion of a VM.
VDP can also protect against more significant failures such as the loss of an entire site. The first way this can be addressed is by using the backup data replication feature that is built into VDP. It is possible to back up data locally and then replicate this backup data to another VDP appliance.
It is also possible to replicate backup data from VDP to EMC Avamar. Avamar could be located in the customer’s data center or hosted at a service provider as part of a backup data hosting offering. If multi-tenancy is required, VDP supports it as discussed here.
Another option is to utilize EMC Data Domain as a backup data target for VDP. Data Domain Boost (DDBoost) is built into VDP and, assuming DDBoost is licensed on the Data Domain appliance, this enables a very efficient and reliable means to store backup data separate from production data. Data Domain deduplication and compression is outstanding. Below is a screen shot showing pre- and post-compression numbers for two VDP appliances I have in my environment. Note that over 2TB of raw backup data has been ingested by the two VDP appliances. After compression, only 127GB of capacity on the Data Domain appliances is consumed.
Better yet, what if we employ both approaches? It is certainly supported and looks something like the diagram below. The virtual appliances are VDP appliances and the black boxes are EMC Data Domain (physical) appliances.
You might be asking "What happens if I lose the VDP appliance?" VDP includes the option "Enable Checkpoint Copy", which enables a new VDP appliance to restore existing backup data from a Data Domain system if the original VDP appliance is lost.
As you can see there are a few ways to design a backup solution using VDP and Data Domain for VSAN (and other storage solutions, for that matter). Using Data Domain to store VDP backup data makes sense for a few reasons:
- Backup data is separate from production data
- Deduplication and compression reduce the storage capacity consumed by backup data
- Data Domain provides a very reliable platform for housing backup data
- VDP works seamlessly with Data Domain using DDBoost
- Data Domain enables scale beyond the 8TB limit imposed by a VDP appliance
- VDP is still limited to a supported maximum of 400 VMs per VDP appliance
- 1 VDP appliance per DD160, DD620, and DD2200
- Up to 2 VDP appliances per DD2500 and DD4xxx
- Up to 3 VDP appliances per DD7200 and DD990
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