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ONTAP SAN Host Utilities

Configure RHEL 8.7 for NVMe-oF with ONTAP storage

Contributors netapp-sarajane
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Red Hat Enterpirse Linux (RHEL) hosts support the NVMe over Fibre Channel (NVMe/FC) and NVMe over TCP (NVMe/TCP) protocols with Asymmetric Namespace Access (ANA). ANA provides multipathing functionality equivalent to asymmetric logical unit access (ALUA) in iSCSI and FCP environments.

Learn how to configure NVMe over Fabrics (NVMe-oF) hosts for RHEL 8.7. For more support and feature information, see NVME-oF Overview.

NVMe-oF with RHEL 8.7 has the following known limitations:

  • SAN booting using the NVMe-oF protocol is not currently supported.

  • In-kernel NVMe multipath is disabled by default on NVMe-oF hosts in RHEL 8.7; you must enable it manually.

  • NVMe/TCP is available as a technology preview due to known issues.

Step 1: Optionally, enable SAN booting

You can configure your host to use SAN booting to simplify deployment and improve scalability. Use the Interoperability Matrix Tool to verify that your Linux OS, host bus adapter (HBA), HBA firmware, HBA boot BIOS, and ONTAP version support SAN booting.

Steps

  1. Create a NVMe namespace and map it to the host.

  2. Enable SAN booting in the server BIOS for the ports to which the SAN boot namespace is mapped.

    For information on how to enable the HBA BIOS, see your vendor-specific documentation.

  3. Reboot the host and verify that the OS is up and running.

Step 2: Verify the software version and NVMe configuration

Check that your system meets software requirements and verify NVMe package installations and host configuration.

Steps

  1. Install RHEL 8.7 on the server. After the installation is complete, verify that you are running the required RHEL 8.7 kernel:

    uname -r

    Example RHEL kernel version:

    4.18.0-425.3.1.el8.x86_64

  2. Install the nvme-cli package:

    rpm -qa|grep nvme-cli

    The following example shows an nvme-cli package version:

    nvme-cli-1.16-5.el8.x86_64

  3. Install the libnvme package:

    rpm -qa|grep libnvme

    The following example shows an libnvme package version:

    libnvme-1.2-3.el8.x86_64

  4. Enable in-kernel NVMe multipath:

    grubby --args=nvme_core.multipath=Y --update-kernel /boot/vmlinuz-4.18.0-425.3.1.el8.x86_64

  5. On the RHEL 8.7 host, check the hostnqn string at /etc/nvme/hostnqn:

    cat /etc/nvme/hostnqn

    The following example shows an hostnqn version:

    nqn.2014-08.org.nvmexpress:uuid:a7f7a1d4-311a-11e8-b634-7ed30aef10b7

  6. Verify that the hostnqn string matches the hostnqn string for the corresponding subsystem on the ONTAP storage system:

    ::> vserver nvme subsystem host show -vserver vs_nvme167
    Show example 
    Vserver     Subsystem          Host NQN
----------- --------------- ----------------------------------------------------------
vs_nvme167   rhel_167_LPe35002    nqn.2014-08.org.nvmexpress:uuid:a7f7a1d4-311a-11e8-b634-7ed30aef10b7
    Note If the hostnqn strings do not match, use the vserver modify command to update the hostnqn string on your corresponding ONTAP storage system subsystem to match the hostnqn string from /etc/nvme/hostnqn on the host.

  7. Reboot the host.

    Note

    To run both NVMe and SCSI traffic on the same host, NetApp recommends using the in-kernel NVMe multipath for ONTAP namespaces and dm-multipath for ONTAP LUNs. To prevent dm-multipath from claiming ONTAP namespace devices, exclude them by adding the enable_foreign setting to the /etc/multipath.conf file:

    cat /etc/multipath.conf
defaults {
        enable_foreign     NONE
}

  8. Restart the multipathd daemon by running a systemctl restart multipathd.

Step 3: Configure NVMe/FC and NVMe/TCP

Configure NVMe/FC with Broadcom/Emulex or Marvell/QLogic adapters, or configure NVMe/TCP using manual discovery and connect operations.

FC - Broadcom/Emulex

Configure NVMe/FC for a Broadcom/Emulex adapter.

Steps

  1. Verify that you are using the supported adapter model:

    1. Display the model names:

      cat /sys/class/scsi_host/host*/modelname

      You should see output similar to the following example:

      LPe35002-M2
LPe35002-M2

    2. Display the model descriptions:

      cat /sys/class/scsi_host/host*/modeldesc

      You should see output similar to the following example:

      Emulex LightPulse LPe35002-M2 2-Port 32Gb Fibre Channel Adapter
Emulex LightPulse LPe35002-M2 2-Port 32Gb Fibre Channel Adapter

  2. Verify that you are using the recommended Broadcom lpfc firmware and inbox driver:

    1. Display the firmware version:

      cat /sys/class/scsi_host/host*/fwrev

      The command returns the firmware versions:

      14.0.505.12, sli-4:6:d
14.0.505.12, sli-4:6:d

    2. Display the inbox driver version:

      cat /sys/module/lpfc/version

      The following example shows a driver version:

      0:14.0.0.15

    For the current list of supported adapter driver and firmware versions, see the Interoperability Matrix Tool.

  3. Verify that lpfc_enable_fc4_type is set to 3:

    cat /sys/module/lpfc/parameters/lpfc_enable_fc4_type

  4. Verify that you can view your initiator ports:

    cat /sys/class/fc_host/host*/port_name

    You should see output similar to the following example:

    0x100000109b95467c
0x100000109b95467b

  5. Verify that your initiator ports are online:

    cat /sys/class/fc_host/host*/port_state

    You should see the following output:

    Online
Online

  6. Verify that the NVMe/FC initiator ports are enabled and that the target ports are visible:

    cat /sys/class/scsi_host/host*/nvme_info
    Show example 
    NVME Initiator Enabled
XRI Dist lpfc1 Total 6144 IO 5894 ELS 250
NVME LPORT lpfc1 WWPN x100000109b95467c WWNN x200000109b95467c DID x0a1500 ONLINE
NVME RPORT       WWPN x2071d039ea36a105 WWNN x206ed039ea36a105 DID x0a0907 TARGET DISCSRVC ONLINE
NVME RPORT       WWPN x2072d039ea36a105 WWNN x206ed039ea36a105 DID x0a0805 TARGET DISCSRVC ONLINE

NVME Statistics
LS: Xmt 00000001c7 Cmpl 00000001c7 Abort 00000000
LS XMIT: Err 00000000  CMPL: xb 00000000 Err 00000000
Total FCP Cmpl 0000000004909837 Issue 0000000004908cfc OutIO fffffffffffff4c5
abort 0000004a noxri 00000000 nondlp 00000458 qdepth 00000000 wqerr 00000000 err 00000000
FCP CMPL: xb 00000061 Err 00017f43

NVME Initiator Enabled
XRI Dist lpfc0 Total 6144 IO 5894 ELS 250
NVME LPORT lpfc0 WWPN x100000109b95467b WWNN x200000109b95467b DID x0a1100 ONLINE
NVME RPORT       WWPN x2070d039ea36a105 WWNN x206ed039ea36a105 DID x0a1007 TARGET DISCSRVC ONLINE
NVME RPORT       WWPN x206fd039ea36a105 WWNN x206ed039ea36a105 DID x0a0c05 TARGET DISCSRVC ONLINE

NVME Statistics
LS: Xmt 00000001c7 Cmpl 00000001c7 Abort 00000000
LS XMIT: Err 00000000  CMPL: xb 00000000 Err 00000000
Total FCP Cmpl 0000000004909464 Issue 0000000004908531 OutIO fffffffffffff0cd
abort 0000004f noxri 00000000 nondlp 00000361 qdepth 00000000 wqerr 00000000 err 00000000
FCP CMPL: xb 0000006b Err 00017f99
FC - Marvell/QLogic

Configure NVMe/FC for a Marvell/QLogic adapter.

Steps

  1. Verify that you are using the supported adapter driver and firmware versions:

    cat /sys/class/fc_host/host*/symbolic_name

    The following example shows driver and firmware versions:

    QLE2772 FW:v9.08.02 DVR:v10.02.07.400-k-debug
QLE2772 FW:v9.08.02 DVR:v10.02.07.400-k-debug

  2. Verify that ql2xnvmeenable is set. This enables the Marvell adapter to function as an NVMe/FC initiator:

    cat /sys/module/qla2xxx/parameters/ql2xnvmeenable

    The expected output is 1.

TCP

The NVMe/TCP protocol doesn't support the auto-connect operation. Instead, you can discover the NVMe/TCP subsystems and namespaces by performing the NVMe/TCP connect or connect-all operations manually.

Steps

  1. Check that the initiator port can get the discovery log page data across the supported NVMe/TCP LIFs:

    nvme discover -t tcp -w host-traddr -a traddr
    Show example 
    nvme discover -t tcp -w 192.168.211.5 -a 192.168.211.14

Discovery Log Number of Records 8, Generation counter 10

=====Discovery Log Entry 0======
trtype:  tcp
adrfam:  ipv4
subtype: unrecognized
treq:    not specified
portid:  0
trsvcid: 8009
subnqn:  nqn.199208.com.netapp:sn.154a5833c78c11ecb069d039ea359e4b:discovery
traddr:  192.168.211.15
sectype: none
=====Discovery Log Entry 1======
trtype:  tcp
adrfam:  ipv4
subtype: unrecognized
treq:    not specified
portid:  1
trsvcid: 8009
subnqn:  nqn.1992-08.com.netapp:sn.154a5833c78c11ecb069d039ea359e4b:discovery
traddr:  192.168.111.15
sectype: none
=====Discovery Log Entry 2======
trtype:  tcp
adrfam:  ipv4
subtype: unrecognized
treq:    not specified
portid:  2
trsvcid: 8009
subnqn:  nqn.1992-08.com.netapp:sn.154a5833c78c11ecb069d039ea359e4b:discovery
traddr:  192.168.211.14
sectype: none
=====Discovery Log Entry 3======
trtype:  tcp
adrfam:  ipv4
subtype: unrecognized
treq:    not specified
portid:  3
trsvcid: 8009
subnqn:  nqn.1992-08.com.netapp:sn.154a5833c78c11ecb069d039ea359e4b:discovery
traddr:  192.168.111.14
sectype: none
=====Discovery Log Entry 4======
trtype:  tcp
adrfam:  ipv4
subtype: nvme subsystem
treq:    not specified
portid:  0
trsvcid: 4420
subnqn:  nqn.1992-08.com.netapp:sn.154a5833c78c11ecb069d039ea359e4b:subsystem.rhel_tcp_165
traddr:  192.168.211.15
sectype: none
=====Discovery Log Entry 5======
trtype:  tcp
adrfam:  ipv4
subtype: nvme subsystem
treq:    not specified
portid:  1
trsvcid: 4420
subnqn:  nqn.1992-08.com.netapp:sn.154a5833c78c11ecb069d039ea359e4b:subsystem.rhel_tcp_165
traddr:  192.168.111.15
sectype: none
=====Discovery Log Entry 6======

trtype:  tcp
adrfam:  ipv4
subtype: nvme subsystem
treq:    not specified
portid:  2
trsvcid: 4420
subnqn:  nqn.1992-08.com.netapp:sn.154a5833c78c11ecb069d039ea359e4b:subsystem.rhel_tcp_165
traddr:  192.168.211.14
sectype: none

=====Discovery Log Entry 7======
trtype:  tcp
adrfam:  ipv4
subtype: nvme subsystem
treq:    not specified

   portid:  3

trsvcid: 4420
subnqn:  nqn.1992-08.com.netapp:sn.154a5833c78c11ecb069d039ea359e4b:subsystem.rhel_tcp_165
traddr:  192.168.111.14
sectype: none
[root@R650-13-79 ~]#

  2. Verify that the other NVMe/TCP initiator-target LIF combinations can successfully fetch discovery log page data:

    nvme discover -t tcp -w host-traddr -a traddr
    Show example 
    nvme discover -t tcp -w 192.168.211.5 -a 192.168.211.14
nvme discover -t tcp -w 192.168.211.5 -a 192.168.211.15
nvme discover -t tcp -w 192.168.111.5 -a 192.168.111.14
nvme discover -t tcp -w 192.168.111.5 -a 192.168.111.15

  3. Run the nvme connect-all command across all the supported NVMe/TCP initiator-target LIFs across the nodes:

    nvme connect-all -t tcp -w host-traddr -a traddr -1 1800
    Show example 
    nvme connect-all -t tcp -w 192.168.211.5-a 192.168.211.14 -l 1800
nvme connect-all -t tcp -w 192.168.211.5 -a 192.168.211.15 -l 1800
nvme connect-all -t tcp -w 192.168.111.5 -a 192.168.111.14 -l 1800
nvme connect-all -t tcp -w 192.168.111.5 -a 192.168.111.15 -l 1800

Step 4: Optionally, enable 1MB I/O for NVMe/FC

ONTAP reports a Max Data Transfer Size (MDTS) of 8 in the Identify Controller data. This means the maximum I/O request size can be up to 1MB. To issue I/O requests of size 1MB for a Broadcom NVMe/FC host, you should increase the lpfc value of the lpfc_sg_seg_cnt parameter to 256 from the default value of 64.

Note These steps don't apply to Qlogic NVMe/FC hosts.
Steps

  1. Set the lpfc_sg_seg_cnt parameter to 256:

    cat /etc/modprobe.d/lpfc.conf

    You should see an output similar to the following example:

    options lpfc lpfc_sg_seg_cnt=256

  2. Run the dracut -f command, and reboot the host.

  3. Verify that the value for lpfc_sg_seg_cnt is 256:

    cat /sys/module/lpfc/parameters/lpfc_sg_seg_cnt

Step 5: Validate NVMe-oF

Verify that the in-kernel NVMe multipath status, ANA status, and ONTAP namespaces are correct for the NVMe-oF configuration.

Steps

  1. Verify that the in-kernel NVMe multipath is enabled:

    cat /sys/module/nvme_core/parameters/multipath

    You should see the following output:

    Y

  2. Verify that the appropriate NVMe-oF settings (such as, model set to NetApp ONTAP Controller and load balancing iopolicy set to round-robin) for the respective ONTAP namespaces correctly reflect on the host:

    1. Display the subsystems:

      cat /sys/class/nvme-subsystem/nvme-subsys*/model

      You should see the following output:

      NetApp ONTAP Controller
NetApp ONTAP Controller

    2. Display the policy:

      cat /sys/class/nvme-subsystem/nvme-subsys*/iopolicy

      You should see the following output:

      round-robin
round-robin

  3. Verify that the namespaces are created and correctly discovered on the host:

    nvme list
    Show example 
    Node         SN                   Model
---------------------------------------------------------
/dev/nvme4n1 81Ix2BVuekWcAAAAAAAB	NetApp ONTAP Controller


Namespace Usage    Format             FW             Rev
-----------------------------------------------------------
1                 21.47 GB / 21.47 GB	4 KiB + 0 B   FFFFFFFF

  4. Verify that the controller state of each path is live and has the correct ANA status:

    nvme list-subsys /dev/nvme1n1
    Show example 
    nvme-subsys0 - NQN=nqn.1992-08.com.netapp:sn.154a5833c78c11ecb069d039ea359e4b:subsystem.rhel_tcp_165
\
 +- nvme0 tcp traddr=192.168.211.15 trsvcid=4420 host_traddr=192.168.211.5 live non-optimized
 +- nvme1 tcp traddr=192.168.211.14 trsvcid=4420 host_traddr=192.168.211.5 live optimized
 +- nvme2 tcp traddr=192.168.111.15 trsvcid=4420 host_traddr=192.168.111.5 live non-optimized
 +- nvme3 tcp traddr=192.168.111.14 trsvcid=4420 host_traddr=192.168.111.5 live optimized

  5. Verify that the NetApp plug-in displays the correct values for each ONTAP namespace device:

    Column
    nvme netapp ontapdevices -o column
    Show example 
    Device       Vserver          Namespace Path
---------    -------          --------------------------------------------------
/dev/nvme0n1 vs_tcp79     /vol/vol1/ns1 

NSID  UUID                                   Size
----  ------------------------------         ------
1     79c2c569-b7fa-42d5-b870-d9d6d7e5fa84  21.47GB
    JSON
    nvme netapp ontapdevices -o json
    Show example 
    {

  "ONTAPdevices" : [
  {

      "Device" : "/dev/nvme0n1",
      "Vserver" : "vs_tcp79",
      "Namespace_Path" : "/vol/vol1/ns1",
      "NSID" : 1,
      "UUID" : "79c2c569-b7fa-42d5-b870-d9d6d7e5fa84",
      "Size" : "21.47GB",
      "LBA_Data_Size" : 4096,
      "Namespace_Size" : 5242880
    },

]

}

Step 6: Review the known issues

These are the known issues:

NetApp Bug ID Title Description

1479047

RHEL 8.7 NVMe-oF hosts create duplicate persistent discovery controllers (PDCs)

On NVMe-oF hosts, you can use the "nvme discover -p" command to create PDCs. When this command is used, only one PDC should be created per initiator-target combination. However, if you are running RHEL 8.8 on an NVMe-oF host, a duplicate PDC is created each time "nvme discover -p" is executed. This leads to unnecessary usage of resources on both the host and the target.