Recovery

Recovery is critical for status restoration (both control plane and data plane) for cases such as controller restart, live update, or live migration.

The recovery process relies on JSON files stored in /opt/mellanox/mlnx_virtnet/recovery, where each device (either PF or VF) has a corresponding file named after its unique VUID.

The following entries are saved to the recovery file and restored when necessary:

Entry	Type	Description
`port_ib_dev`	String	RDMA device name the virtio-net device is created on
`pf_id`	Number	ID of PF
`vf_id`	Number	ID of VF, valid for VF only
`function_type`	String	PF or VF
`bdf_raw`	Number	Virtio-net device bus:device:function in uint16 type
`device_type`	String	Static or hotplug (only for PF)
`mac`	String	MAC address of device
`pf_num`	Number	PCIe function number
`sf_num`	Number	SF number which was used for this virtio-net device
`mq`	Number	Number of multi-queue created for this virtio-net device

An example of recovery file for a hotplug PF device:

Copy
Copied!

            
            {
  "port_ib_dev": "mlx5_0",
  "pf_id": 0,
  "function_type": "pf",
  "bdf_raw": 57611,
  "device_type": "hotplug",
  "mac": "0c:c4:7a:ff:22:93",
  "pf_num": 0,
  "sf_num": 2000,
  "mq": 3
}

Use Cases

Depending on the actions of the BlueField or host, recovery may or may not be performed. Please refer to the following table for individual scenarios:

	DPU Actions			Host Actions
	Restart Controller	Live Update	Hot Unplug	Destroy VFs	Unload Driver	Power Cycle Host & DPU	Warm Reboot	Live Migration
`Static PF`	Recover	Recover	N/A	N/A	Recover	No recover	Recover	Recover
`Hotplug PF`	Recover	Recover	No recover	N/A	Recover	No recover	Recover	Recover
`VF`	Recover	Recover	N/A	Recovery file deleted	No Recover	No recover	No recover	Recover

Note

These recovery files are internal to the controller and should not be modified.

Note

Controller recovery is enabled by default and does not need user configuration or intervention. When the mlxconfig settings used by the controller take effect, the newly started controller service automatically deletes all recovery files.