For VMware environments, NAKIVO Backup & Replication uses LAN-free storage access modes, allowing you to divide production, and backup and replication data streams. This results in faster backup and replication and less load on the production LAN and ESXi hosts.
The default configuration of the solution is set to automatically run a backup and replication in the Direct SAN Access mode, then in Hot Add. Should the previous two options not be applicable, the product will perform backups over LAN.
Direct SAN Access for VMware
Storage Area Network (SAN) is a major component of enterprise data centers. Availability of SAN has long been a requirement for taking advantage of all enterprise features that can be found in today’s virtualization products. Since Storage Area Networks are built for high performance and redundancy, they contain multiple storage controllers, I/O cards, drives, network connectivity, etc. They can also be quite pricey.
NAKIVO Backup & Replication ensures that you use SAN as efficiently as possible. Unlike traditional solutions that negatively impact disk I/O performance, it uses a built-in technology which allows you to directly access a SAN unit to achieve the best transfer speed and efficiency.´
The Direct SAN Access mode can be enabled for VMware backup, replication, and recovery. It allows you to bypass the network and transport data directly over a SAN without making any write/modification operations on the SAN LUNs.
To enable the Direct SAN Access mode, the following requirements should be met:
You have iSCSI connectivity (iSCSI network) to the iSCSI target.
The source Transporter that reads virtual machine data from the SAN must be either a physical machine connected to the SAN or a virtual machine running on a VMware ESXi host that is connected to the SAN.
If using a Windows virtual machine, make sure the virtual machine with the source Transporter is not managed by either the VMware vCenter server or ESXi host you are to back up or replicate.
Refer to the corresponding article in NAKIVO Backup & Replication User Guide to know how to set up SAN access and how to configure the Direct SAN Access mode.
Hot Add for VMware
When the Hot Add mode is enabled, NAKIVO Backup & Replication reads VM data directly from the VM datastores through the storage I/O stack, bypassing the host’s TCP/IP stack that would otherwise impact every VM hosted on the server, and slow down the data transfer.
Use the Hot Add transport mode when direct SAN access is not available – for example, if you simply do not use SAN or if, for some reason, you do not want to load the SAN network.
Hot Add offers almost the same performance as the Direct SAN Access mode, but it also has limitations:
NAKIVO Backup & Replication must be installed on the virtual machine so a virtual disk can be mounted to it.
The VM with the product should have direct access to the storage where a source VM resides. This storage may be the same physical disk if the product and the source VM are on the same host. In other cases, such storage may be a shared host, like NAS or SAN.
The Hot Add transport mode is not supported for IDE disks.
For additional information, refer to the corresponding article in NAKIVO Backup & Replication User Guide.