How to check ISCSI paths on Windows Server, VMware ESXI and Proxmox

Introduction

Ensuring shared storage high availability is critical for any virtualized environment. This being said, it is important to incorporate checks of iSCSI multipathing configuration and functioning in the routine health checks. This article provides instructions on how to check StarWind HA devices’ state, make sure that iSCSI sessions are connected, and validate path health across three major platforms: Windows Server, VMware ESXi, and Proxmox VE.

Checking StarWind HA devices’ status

It is important to start any check from StarWind’s highly available (HA) devices synchronization status. There are several ways to check it.

For environments that have StarWind VSAN deployed as a Windows-based service, StarWind Management Console should be used.

For environments that have StarWind VSAN deployed as CVM or Linux bare-metal StarWind VSAN installations, both StarWind CVM WEB UI and Windows-based StarWind Management Console can be used.

NOTE: Both options are applicable to commercial and free StarWind VSAN editions.

Option 1: StarWind VSAN CVM WEB UI

1. Using a browser, connect to StarWind VSAN CVM WEB UI.
2. Go to the Appliances tab, make sure that all CVM nodes are listed ONLINE.
   NOTE: If any is OFFLINE, and no hardware or network failure is found contact StarWind Support https://www.starwindsoftware.com/support-form.
3. Go to the LUNs menu.

See if all StarWind LUNS are Highly Available and Online.
NOTE: If a LUN is listed as Standalone, the storage cannot be highly available by design. Proceed with caution.

Option 2: Windows-based StarWind Management Console

NOTE: Windows-based StarWind Management Console can be downloaded from StarWind CVM WEB UI: Log in to WEB UI > Gear-shaped button > Downloads > StarWind Management Console. Download and install the application. During the installation process, select StarWind Management Console from the dropdown menu.

For StarWind VSAN deployed as a Windows application, use https://starwind.com/tmplink/starwind-v8.exe.

1. Open StarWind Management Console and start it from the Windows tray.
2. Add the servers if needed (localhost address or hostnames for Windows-based scenarios or StarWind CVM machine IP address).
3. Double-click each server.
4. Expand each target.
5. See if the devices are Synchronized and check any warnings on them.

If a device has a state other than Storage is working properly, the corresponding ISCSI target may be unavailable for client connections.

Press Replication Manager button to open it and check the status of the partner device. The status should be Synchronized as well.

Checking iSCSI Targets status on Windows Server

Option 1: Using the iSCSI Initiator GUI

1. Open the iSCSI Initiator from the Start menu or by running iscsicpl.exe
2. Navigate to the Targets tab.
3. Click the Refresh button under the Discovered targets section.
4. Review the active sessions. The targets from all replication partners and standalone hosts should be listed. All of them should be in the Connected state.

NOTE: Witness target on replication partners in Hyperconverged scenarios where VSAN is installed as a Windows-native application can be Inactive.

The ISCSI sessions on a simple 2-nodes setup with Witness and CSV targets should look like below:

Option 2: Using PowerShell

To quickly check iSCSI sessions via CLI, run the following cmdlet. StarWind HA devices must be connected from each replication partner. Pay attention to the IsConnected : True property.

Get-IscsiSession

Sample Output:

Watch out for the line:
IsConnected   : True

Option 3: StarWind Log Collector

This option works for any Windows client that has StarWind VSAN targets connected to it.

1. Download StarWind Log Collector https://knowledgebase.starwindsoftware.com/troubleshooting/how-to-collect-logs-with-starwind-log-collector/.
2. Save and unzip it.
3. Run the *.exe as administrator. The collector will produce a ZIP archive with the logs.
4. Open the archive.
5. Locate iscsi-report.html.
6. Each target must be listed as TRUE in the Connected column. Each target must be connected from each StarWind VSAN replication partner.

Checking iSCSI Paths on VMware ESXi

vSphere Client (vCenter) is the fastest way to verify paths in VMware.

1. Navigate to Host: Host → Storage → Adapters.
2. Click Refresh and Rescan.
   
3. Verify the individual devices: Go to Host → Storage → Storage Devices → iSCSI LUN → Paths.
4. Click Refresh.
   • Status Check: All paths and targets for HA devices from all nodes where devices are replicated should be visible and marked as Active (Active I/O).
     

multipath -ll

iscsiadm -m session

tcp: [1] 192.168.10.20:3260,1 iqn.2008-08.com.starwindsoftware:starwind01-share  

tcp: [2] 192.168.10.21:3260,1 iqn.2008-08.com.starwindsoftware:starwind02-share

iscsiadm -m session -P 3

echo "=== ISCSI SESSIONS ==="

iscsiadm -m session

echo -e "\n=== MULTIPATH STATUS ==="

multipath -ll

echo -e "\n=== DEAD PATHS ==="

multipath -ll | grep -i "failed\|faulty\|offline"

echo -e "\n=== KERNEL BLOCK PATHS ==="

lsblk -o NAME,HCTL,STATE