All PowerMax, VMAX All Flash, and VMAX3: Customer reports iSCSI paths drop and some recover without Dell Intervention
Summary: Customer reports the VMWare/ESX hosts reposts iSCSI paths drop. Some paths recover on their own with no intervention needed from Dell Support.
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Symptoms
Using the software iSCSI initiator in VMware ESXi. iSCSI LUN connectivity issues on ESX/ESXi.
Multiple VMkernel portgroups in the same subnet, accessing the same iSCSI target
iSCSI connections are frequently being marked as offline, but not all connections come back online again.
Multiple dead paths accumulate over time.
Multiple VMkernel portgroups in the same subnet, accessing the same iSCSI target
iSCSI connections are frequently being marked as offline, but not all connections come back online again.
Multiple dead paths accumulate over time.
- No actual network traffic loss is experienced
- iSCSI initiator reconnecting randomly after reboot
- The ESXi server's /var/log/vmkernel.log file frequently displays warnings similar to:
vmkernel: 57:14:42:01.498 cpu5:4321)WARNING: iscsi_vmk: iscsivmk_ConnReceiveAtomic: vmhba34:CH:0 T:6 CN:0: Failed to receive data: Connection closed by peer vmkernel: 57:14:42:01.498 cpu5:4321)iscsi_vmk: iscsivmk_ConnRxNotifyFailure: vmhba34:CH:0 T:6 CN:0: Connection rx notifying failure: Failed to Receive. State=Online vmkernel: 57:14:42:01.498 cpu5:4321)WARNING: iscsi_vmk: iscsivmk_StopConnection: vmhba34:CH:0 T:6 CN:0: Processing CLEANUP event vmkernel: 57:14:42:01.748 cpu4:4321)WARNING: iscsi_vmk: iscsivmk_StopConnection: vmhba34:CH:0 T:6 CN:0: iSCSI connection is being marked "OFFLINE" [...] vmkernel: 57:14:42:07.835 cpu1:4321)WARNING: iscsi_vmk: iscsivmk_StartConnection: vmhba34:CH:0 T:6 CN:0: iSCSI connection is being marked "ONLINE"
Cause
The iSCSI connection is closed by the iSCSI target, and the connection closed by the peer. Refers to TCP session reset/closure that is sent from the target storage to the ESXi host.
A network error occurred while the client was receiving data from the server.
This issue occurs due to improper storage array configuration, host networking configuration, or the VMware ESXi product.
The server accepts the connection, processes the request, and sends a reply to the client. When the server closes the socket, the client believes that the connection has been terminated abnormally because the socket implementation sends a TCP reset segment telling the client to throw away the data and report an error.
Oversaturation of the SAN or SAN array, resulting in loss of communication, or storage task completion after the ESXi host has already stopped the task due to timeout (5000 ms). Duplicate SAN targets IP addresses, resulting in intermittent connection loss and other anomalous behavior.
SAN target connection load balancing. Disable connection load balancing when using VMware ESXi software iSCSI initiators. You can use the Round-Robin multipathing policy to configure load balancing.
VMkernel networking misconfiguration:
When using multiple VMkernel ports for iSCSI software, ensure that the number of VMkernel ports is lesser than or equal to the number of physical network interfaces.
Check MTU size across your environment.
Ensure the following Best Practices for Configuring Networking with Software iSCSI.
A network error occurred while the client was receiving data from the server.
This issue occurs due to improper storage array configuration, host networking configuration, or the VMware ESXi product.
The server accepts the connection, processes the request, and sends a reply to the client. When the server closes the socket, the client believes that the connection has been terminated abnormally because the socket implementation sends a TCP reset segment telling the client to throw away the data and report an error.
Oversaturation of the SAN or SAN array, resulting in loss of communication, or storage task completion after the ESXi host has already stopped the task due to timeout (5000 ms). Duplicate SAN targets IP addresses, resulting in intermittent connection loss and other anomalous behavior.
SAN target connection load balancing. Disable connection load balancing when using VMware ESXi software iSCSI initiators. You can use the Round-Robin multipathing policy to configure load balancing.
VMkernel networking misconfiguration:
When using multiple VMkernel ports for iSCSI software, ensure that the number of VMkernel ports is lesser than or equal to the number of physical network interfaces.
Check MTU size across your environment.
Ensure the following Best Practices for Configuring Networking with Software iSCSI.
Resolution
If iSCSI paths recover on their own with no intervention from Dell, this issue is an external issue.
To resolve this issue, collect the TCP dump during these messages and the storage OEM should identify the reason.
https://kb.vmware.com/s/article/1016836
Affected Products
PowerMax, PowerMax 2000, PowerMax 2500, PowerMax 8000, PowerMax 8500, VMAX 450F, VMAX 850F, VMAX 950F, VMAX All Flash, VMAX3 SeriesArticle Properties
Article Number: 000204525
Article Type: Solution
Last Modified: 06 Aug 2025
Version: 4
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