Monitoring MPIO

This topic will cover the MPIO Console, virtual disks, host ports, DataCore Servers, and using ALUA.

DataCore MPIO Console

The MPIO Console is used to monitor multipath virtual disks and paths on the MPIO host server. There are three main components in the console tree:

• Virtual disks
• Host ports
• DataCore Servers

Each component provides monitoring of the virtual disks and associated front-end paths from different perspectives.

Component	Overview
Virtual Disks	Monitors virtual disk health and associated paths from the virtual disk perspective. Path information is presented per virtual disk.
Host Ports	Monitors paths from the initiator port perspective.  Path information is presented per initiator port.
DataCore Servers	Monitors paths from the server perspective. Path information is presented per DataCore Server.

Virtual Disks

The Virtual Disks component monitors paths from the virtual disk perspective.  Path information is provided in two views:

• A summary showing path information and health status for each virtual disk for a quick overview of the health of all virtual disks.
• Detailed path information is provided for each virtual disk.

Summary Information

To view a summary of basic information and health status for all virtual disks:

In the console tree, click Virtual Disks. In the right pane is the summary of all virtual disks.

Possible virtual disk statuses:

• Healthy
• Path(s) offline

Detailed Information

To view detailed path information per virtual disk:

In the console tree, expand Virtual Disks and click on a virtual disk. In the right pane is the complete path information for that virtual disk. All paths to the selected virtual disk are displayed.

Possible path statuses:

• Online
• Offline

The Path ID is provided by the operating system. It is a property of the disk and is displayed on the MPIO tab. See Viewing Disk Properties.

Host Ports

The Host Ports component monitors paths from the initiator port perspective.

Path information is provided in two views:

• A brief summary showing SCSI port and path counts for all Fibre Channel or iSCSI adapters in the host which are being used for virtual disks paths.
• Detailed target path information is provided for each host port. 

Summary Information

To view a summary of ports in the host:

In the console tree, click Host Ports. In the right pane is the summary of all ports in the host along with the number of paths that are using each port.

SCSI Port is the SCSI port number assigned by Windows operating system.

Detailed Information

To view detailed path information per port:

In the console tree, expand Host Ports and click on a port. In the right pane is the complete target path information for that port.

Possible path statuses:

• Online
• Offline

The Path ID is provided by the operating system. It is a property of the disk and is displayed in the MPIO tab. See Viewing Disk Properties.

DataCore Servers

The DataCore Servers component monitors paths from the storage server perspective. Path information is provided in two views:

• A brief summary of the path and virtual disk count of all DataCore Servers.
• Detailed path information is provided for each DataCore Server.

Summary Information

To view a summary of storage servers:

In the console tree, click DataCore Servers. In the right pane is the summary of all servers, along with the number of paths being used and virtual disks for each server.

Active Virtual Disk Count is the number of virtual disks ready and actively waiting for I/O on each server.

Detailed Information

To view detailed path information per DataCore Server:

In the console tree, expand DataCore Servers and click on a server. In the right pane is the complete path information for that server.

Possible path statuses:

• Online
• Offline

Using ALUA

ALUA commands are supported on the host. ALUA provides a standardized mechanism for path discovery and prioritization and allows initiator ports to discover multiple paths from the target and differentiate between preferred and non-preferred paths.

ALUA path states that are supported and displayed in the console:

• Active/Optimized paths are paths to the preferred server.
• Active/Unoptimized paths are paths to the non-preferred server.
• An Unavailable state occurs when one side of a virtual disk is out of sync.

The ALUA path state displayed in the console is determined by the preferred server setting for the host in DataCore SANsymphony software:

• Auto = paths to the preferred server are Active/Optimized, paths to the non-preferred server are Active/Unoptimized.
• Assigned preferred server = paths to the assigned preferred server are Active/Optimized, paths to the non-preferred server are Active/Unoptimized.
• All = all paths are Active/Optimized.

Implicit control for ALUA is supported; the storage controls the path preference.