Dell PowerFlex 4.6.x Technical Overview

Network stability

Application-level multipathing configurations:

Resilient network connectivity is standard for PowerFlex. Nevertheless the actual implementation may vary. In some cases, the resiliency is attained through LACP or bonding, while other cases through application level multipathing.

In PowerFlex v3.6, additional capabilities were added to support the following error scenario use cases:

Use case one:

• Partial failures on existing connections: While many network issues are manifested as a complete disconnection, some are not, PowerFlex is now aware of degraded connections. Types of degraded connections are:
  • Stable connection and yet very slow vs others.
  • Unstable connection (occasional disconnections).
  • Combination of the above two.

Use case two:

• SDC to SDS proxy connection (in the PowerFlex architecture, each SDC is required to be fully connected to all the SDSs on each of the protection domains it consumes volumes from. In case the SDC is unable to reach one or more of the SDSs, the MDM reflects that and the management APIs raise an alert. In PowerFlex v3.6 a capability was introduced:
  • In case the SDC cannot access the SDS it sends the I/O to another SDS within the same protection domain (or subset of this protection domain). We will refer to this SDS as Proxy-SDS since its only role is to forward the I/O to the SDS which owns the data, receive the I/O result and return it to the initiating SDC.
• PowerFlex supports using the MDM secondary IP addresses as a proxy connection to the Primary MDM.