Found the problem, I think. From: SPDK [mailto:spdk-bounces@lists.01.org] On Behalf Of Isaac Otsiabah Sent: Friday, June 30, 2017 11:34 AM To: &#39;spdk(a)lists.01.org&#39; <spdk(a)lists.01.org&gt; Subject: [SPDK] tgt_node.c: 700:spdk_iscsi_tgt_node_construct: *ERROR*: Could not construct SCSI device I have tested with the "./app/iscsi_tgt/iscsi_tgt -m 0x101" many times but now I am getting this error on both of my test systems. Something has changed? tgt_node.c: 700:spdk_iscsi_tgt_node_construct: *ERROR*: Could not construct SCSI device tgt_node.c: 966:spdk_cf_add_iscsi_tgt_node: *ERROR*: tgt_node1: add_iscsi_target_node error tgt_node.c: 992:spdk_iscsi_init_tgt_nodes: *ERROR*: spdk_cf_add_iscsi_tgt_node() failed iscsi_subsystem.c: 984:spdk_iscsi_init: *ERROR*: spdk_iscsi_init_tgt_nodes() failed subsystem.c: 119:spdk_subsystem_init_next: *ERROR*: Init subsystem iscsi failed my /usr/local/etc/spdk/iscsi.conf contents: ..... ..... ..... [Nvme] TransportID "trtype:PCIe traddr:0000:04:00.0" Nvme0 TransportID "trtype:PCIe traddr:0000:05:00.0" Nvme1 # If 'Yes', iscsi will automatically unbind the kernel NVMe driver from # discovered devices and rebind it to the uio driver. UnbindFromKernel Yes # The following two arguments allow the user to partition NVMe namespaces # into multiple LUNs NvmeLunsPerNs 2 LunSizeInMB 1024 # The number of attempts per I/O when an I/O fails. Do not include # this key to get the default behavior. RetryCount 4 # The maximum number of NVMe controllers to claim. Do not include this key to # claim all of them. #NumControllers 1 [TargetNode1] # Comment "Disk 1" TargetName disk1 TargetAlias "Data Disk1" Mapping PortalGroup1 InitiatorGroup1 AuthMethod Auto AuthGroup AuthGroup1 UseDigest Auto LUN0 Nvme0 LUN1 Nvme1 QueueDepth 128 My systems has these devices before I ran scripts/setup.sh [root@host1]# ls -l /dev/*nv* crw------- 1 root root 248, 0 Jun 30 11:44 /dev/nvme0 brw-rw---- 1 root disk 259, 0 Jun 30 11:44 /dev/nvme0n1 crw------- 1 root root 248, 1 Jun 30 11:44 /dev/nvme1 brw-rw---- 1 root disk 259, 1 Jun 30 11:44 /dev/nvme1n1 crw------- 1 root root 10, 144 Jun 29 18:31 /dev/nvram