A software-implemented iSCSI initiator (in VMware ESX) on one side, the iSCSI Enterprise Target (IET on CentOS5) software on the other side, and a separate storage VLAN to connect the two. Works great in my test lab. But then I wanted to add multipathing to the setup. Plan was: create a second VLAN, and give both the IET server and the iSCSI client a new interface in that VLAN, using a new IP subnet. That gives the client two ways to reach the server, thereby introducing multipathing ! Unfortunately, IET spews error messages at high speed when doing this: I got " kernel: iscsi_trgt: Abort Task (01) issued on tid:1 lun:0 by sid:26459747326427648 (Unknown Task) " about 4000 times per second. Restarted everything without the second storage VLAN and without the new interfaces, and now all is well again.