To estimate the resources required for your Backup & Replication infrastructure you have to answers to the following questions:
•How many sites contain VMs to be backed up?
•How many clusters at each site?
•How many VMs at each site?
•What is the total provisioned VM size at each site?
•How often will the backup jobs be run?
•What is the backup window, that is, how quickly do we need to get the back done?
The following diagram illustrates the flow of data through Veeam Backup and Replication environment and points at which Veeam Backup & Replication collects bottleneck statistics:
•Source (1) refers to the storage from which the backup data is being read. Performance here can be affected by:
oType of disks (SATA vs SAS)
oTransport (FC, iSCSI, NFS, or direct)
ovStorage API method (Direct SAN, Hot-add, or NBD)
See Planning for the Source to learn more.
•Proxy (2) refers to the server that is reading and processing the data. This server performs the compression and deduplication of the data and thus requires significant CPU resources and memory throughput. In general, this system should be as close to the source storage as possible.
•Network (3) refers to the communication between the proxy server and the target. For backup jobs the target is a repository, while for replication job the target is another proxy server. In some cases, generally smaller environments, the proxy and target may be on the same server.
•Target (4) refers to the system that received the compressed/deduped backup data and writes it to the target storage. This can be either a repository or a proxy based on whether the job is a backup or replication job. In general, this system should be as close to the target storage as possible.
To design a Backup & Replication infrastructure with the highest levels of performance attention should be paid to each one of these areas. For example, purchasing a large 16-core CPU server will not help backup performance in case the target is a RAID-6 array built with low-speed disk and a minimal spindle count, or if the network between source and target is limited by 1Gb ethernet.