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NVMe-oF Host Configuration for Oracle Linux 8.8 with ONTAP

Contributors netapp-ranuk netapp-pcarriga
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NVMe over Fabrics (NVMe-oF), including NVMe over Fibre Channel (NVMe/FC) and other transports, is supported with Oracle Linux (OL) 8.8 with Asymmetric Namespace Access (ANA). In NVMe-oF environments, ANA is the equivalent of ALUA multipathing in iSCSI and FC environments and is implemented with in-kernel NVMe multipath.

The following support is available for the NVMe-oF host configuration for OL 8.8 with ONTAP:

  • Support for NVMe over TCP (NVMe/TCP) in addition to NVMe/FC. The NetApp plug-in in the native nvme-cli package displays ONTAP details for both NVMe/FC and NVMe/TCP namespaces.

  • Both NVMe and SCSI traffic can be run on the same co-existent host. Therefore, for SCSI LUNs, you can configure dm-multipath for SCSI mpath devices, whereas you might use NVMe multipath to configure NVMe-oF namespace devices on the host.

  • There is no sanlun support for NVMe-oF. Therefore, there is no host utility support for NVMe-oF on an OL 8.8 host. You can rely on the NetApp plug-in included in the native nvme-cli package for all NVMe-oF transports.

For additional details on supported configurations, see the NetApp Interoperability Matrix Tool.

Features

Oracle Linux 8.8 has in-kernel NVMe multipath enabled for NVMe namespaces by default, therefore, there is no need for explicit settings.

Known limitations

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

Validate software versions

You can use the following procedure to validate the minimum supported OL 8.8 software versions.

Steps

  1. Install OL 8.8 GA on the server. After the installation is complete, verify that you are running the specified OL 8.8 GA kernel.

    # uname -r

    Example output:

    5.15.0-101.103.2.1.el8uek.x86_64

  2. Install the nvme-cli package:

    # rpm -qa|grep nvme-cli

    Example output:

    nvme-cli-1.16-7.el8.x86_64

  3. On the Oracle Linux 8.8 host, check the hostnqn string at /etc/nvme/hostnqn:

    # cat /etc/nvme/hostnqn

    Example output:

    nqn.2014-08.org.nvmexpress:uuid:bc59d14c-47f3-11eb-b93c-3a68dd48673f

  4. Verify that the hostnqn string matches the hostnqn string for the corresponding subsystem on the ONTAP array:

    ::> vserver nvme subsystem host show -vserver vs_ol_nvme

    Example output:

    Vserver     Subsystem          Host NQN
----------- --------------- ----------------------------------------------------------
vs_nvme207   nvme_ss_ol_1    nqn.2014-08.org.nvmexpress:uuid:bc59d14c-47f3-11eb-b93c-3a68dd48673f
    Note If the hostnqn strings do not match, you can use the vserver modify command to update the hostnqn string on your corresponding ONTAP array subsystem to match the hostnqn string from /etc/nvme/hostnqn on the host.

  5. Reboot the host.

    Note

    If you intend to run both NVMe and SCSI co-existent traffic on the same host, NetApp recommends using the in-kernel NVMe multipath for ONTAP namespaces and dm-multipath for ONTAP LUNs respectively. This means that the ONTAP namespaces should be excluded from dm-multipath to prevent dm-multipath from claiming these namespace devices. You can add the enable_foreign setting to the /etc/multipath.conf file:

    # cat /etc/multipath.conf

defaults {
  enable_foreign     NONE
}

    Restart the multipathd daemon by running a systemctl restart multipathd command. This allows the new setting to take effect.

Configure NVMe/FC

You can configure NVMe/FC for Broadcom/Emulex adapters or Marvell/Qlogic adapters.

Broadcom/Emulex
Steps

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

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

    Example output:

    LPe32002-M2
LPe32002-M2
    # cat /sys/class/scsi_host/host*/modeldesc

    Example output:

    Emulex LightPulse LPe32002-M2 2-Port 32Gb Fibre Channel Adapter
Emulex LightPulse LPe32002-M2 2-Port 32Gb Fibre Channel Adapter

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

    # cat /sys/class/scsi_host/host*/fwrev
14.2.539.16, sli-4:2:c
14.2.539.16, sli-4:2:c
    # cat /sys/module/lpfc/version
0:14.2.0.5

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

  3. Verify that lpfc_enable_fc4_type is set to 3:

    # cat /sys/module/lpfc/parameters/lpfc_enable_fc4_type
3

  4. Verify that the initiator ports are up and running, and that you can see the target LIFs:

    # cat /sys/class/fc_host/host*/port_name
0x100000109b3c081f
0x100000109b3c0820
    # cat /sys/class/fc_host/host*/port_state
Online
Online
    # cat /sys/class/scsi_host/host*/nvme_info
NVME Initiator Enabled
XRI Dist lpfc0 Total 6144 IO 5894 ELS 250
NVME LPORT lpfc0 WWPN x100000109b1c1204 WWNN x200000109b1c1204 DID x011d00 ONLINE
NVME RPORT WWPN x203800a098dfdd91 WWNN x203700a098dfdd91 DID x010c07 TARGET DISCSRVC ONLINE
NVME RPORT WWPN x203900a098dfdd91 WWNN x203700a098dfdd91 DID x011507 TARGET DISCSRVC ONLINE
NVME Statistics
LS: Xmt 0000000f78 Cmpl 0000000f78 Abort 00000000
LS XMIT: Err 00000000 CMPL: xb 00000000 Err 00000000
Total FCP Cmpl 000000002fe29bba Issue 000000002fe29bc4 OutIO 000000000000000a
abort 00001bc7 noxri 00000000 nondlp 00000000 qdepth 00000000 wqerr 00000000 err 00000000
FCP CMPL: xb 00001e15 Err 0000d906
NVME Initiator Enabled
XRI Dist lpfc1 Total 6144 IO 5894 ELS 250
NVME LPORT lpfc1 WWPN x100000109b1c1205 WWNN x200000109b1c1205 DID x011900 ONLINE
NVME RPORT WWPN x203d00a098dfdd91 WWNN x203700a098dfdd91 DID x010007 TARGET DISCSRVC ONLINE
NVME RPORT WWPN x203a00a098dfdd91 WWNN x203700a098dfdd91 DID x012a07 TARGET DISCSRVC ONLINE
NVME Statistics
LS: Xmt 0000000fa8 Cmpl 0000000fa8 Abort 00000000
LS XMIT: Err 00000000 CMPL: xb 00000000 Err 00000000
Total FCP Cmpl 000000002e14f170 Issue 000000002e14f17a OutIO 000000000000000a
abort 000016bb noxri 00000000 nondlp 00000000 qdepth 00000000 wqerr 00000000 err 00000000
FCP CMPL: xb 00001f50 Err 0000d9f8
Marvell/QLogic FC Adapter for NVMe/FC

The native inbox qla2xxx driver included in the OL 8.8 GA kernel has the latest fixes. These fixes are essential for ONTAP support.

Steps

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

    # cat /sys/class/fc_host/host*/symbolic_name
QLE2742 FW:v9.12.00 DVR:v10.02.08.100-k
QLE2742 FW:v9.12.00 DVR:v10.02.08.100-k

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

    # cat /sys/module/qla2xxx/parameters/ql2xnvmeenable
1

Enable 1MB I/O size (Optional)

ONTAP reports an MDTS (Max Data Transfer Size) 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 1 MB 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
    options lpfc lpfc_sg_seg_cnt=256

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

  3. Verify that the expected value of lpfc_sg_seg_cnt is 256:

    cat /sys/module/lpfc/parameters/lpfc_sg_seg_cnt

Configure NVMe/TCP

NVMe/TCP does not have auto-connect functionality. Therefore, if a path goes down and is not reinstated within the default time out period of 10 minutes, NVMe/TCP cannot automatically reconnect. To prevent a time out, you should set the retry period for failover events to at least 30 minutes.

Steps

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

    nvme discover -t tcp -w host-traddr -a traddr

    Example output:

    #  nvme discover -t tcp -w 192.168.6.13 -a 192.168.6.15
Discovery Log Number of Records 6, Generation counter 8
=====Discovery Log Entry 0======
trtype: tcp
adrfam: ipv4
subtype: unrecognized
treq: not specified
portid: 0
trsvcid: 8009
subnqn: nqn.1992-08.com.netapp:sn.1c6ac66338e711eda41dd039ea3ad566:discovery
traddr: 192.168.6.17
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.1c6ac66338e711eda41dd039ea3ad566:discovery
traddr: 192.168.5.17
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.1c6ac66338e711eda41dd039ea3ad566:discovery
traddr: 192.168.6.15
sectype: none
=====Discovery Log Entry 3======
trtype: tcp
adrfam: ipv4
subtype: nvme subsystem
treq: not specified
portid: 0
trsvcid: 4420
subnqn: nqn.1992-08.com.netapp:sn.1c6ac66338e711eda41dd039ea3ad566:subsystem.host_95
traddr: 192.168.6.17
sectype: none
..........

  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

    Example output:

    # nvme discover -t tcp -w 192.168.5.13 -a 192.168.5.15
# nvme discover -t tcp -w 192.168.5.13 -a 192.168.5.17
# nvme discover -t tcp -w 192.168.6.13 -a 192.168.6.15
# nvme discover -t tcp -w 192.168.6.13 -a 192.168.6.17

  3. Run the nvme connect-all command across all the supported NVMe/TCP initiator-target LIFs across the nodes, and set the controller loss timeout period for at least 30 minutes or 1800 seconds:

    nvme connect-all -t tcp -w host-traddr -a traddr -l 1800

    Example output:

    # nvme connect-all -t tcp -w 192.168.5.13 -a 192.168.5.15 -l 1800
# nvme connect-all -t tcp -w 192.168.5.13 -a 192.168.5.17 -l 1800
# nvme connect-all -t tcp -w 192.168.6.13 -a 192.168.6.15 -l 1800
# nvme connect-all -t tcp -w 192.168.6.13 -a 192.168.6.17 -l 1800

Validate NVMe-oF

You can use the following procedure to validate NVMe-oF.

Steps

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

    # cat /sys/module/nvme_core/parameters/multipath
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:

    # cat /sys/class/nvme-subsystem/nvme-subsys*/model
NetApp ONTAP Controller
NetApp ONTAP Controller
    # cat /sys/class/nvme-subsystem/nvme-subsys*/iopolicy
round-robin
round-robin

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

    # nvme list

    Example output:

    Node         SN                   Model
---------------------------------------------------------
/dev/nvme0n1 814vWBNRwf9HAAAAAAAB NetApp ONTAP Controller
/dev/nvme0n2 814vWBNRwf9HAAAAAAAB NetApp ONTAP Controller
/dev/nvme0n3 814vWBNRwf9HAAAAAAAB NetApp ONTAP Controller



Namespace Usage    Format             FW             Rev
-----------------------------------------------------------
1                 85.90 GB / 85.90 GB  4 KiB + 0 B   FFFFFFFF
2                 85.90 GB / 85.90 GB  24 KiB + 0 B  FFFFFFFF
3	                85.90 GB / 85.90 GB  4 KiB + 0 B   FFFFFFFF

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

    NVMe/FC
    # nvme list-subsys /dev/nvme0n1

    Example output:

    nvme-subsys0 - NQN=nqn.1992-08.com.netapp:sn.5f5f2c4aa73b11e9967e00a098df41bd:subsystem.nvme_ss_ol_1
\
+- nvme0 fc traddr=nn-0x203700a098dfdd91:pn-0x203800a098dfdd91 host_traddr=nn-0x200000109b1c1204:pn-0x100000109b1c1204 live non-optimized
+- nvme1 fc traddr=nn-0x203700a098dfdd91:pn-0x203900a098dfdd91 host_traddr=nn-0x200000109b1c1204:pn-0x100000109b1c1204 live non-optimized
+- nvme2 fc traddr=nn-0x203700a098dfdd91:pn-0x203a00a098dfdd91 host_traddr=nn-0x200000109b1c1205:pn-0x100000109b1c1205 live optimized
+- nvme3 fc traddr=nn-0x203700a098dfdd91:pn-0x203d00a098dfdd91 host_traddr=nn-0x200000109b1c1205:pn-0x100000109b1c1205 live optimized
    NVMe/TCP
    nvme list-subsys /dev/nvme1n22

    Example output

    nvme-subsys1 - NQN=nqn.1992-   08.com.netapp:sn.68c036aaa3cf11edbb95d039ea243511:subsystem.tcp
\
+- nvme2 tcp traddr=192.168.8.49,trsvcid=4420,host_traddr=192.168.8.1 live non-optimized
+- nvme3 tcp traddr=192.168.8.48,trsvcid=4420,host_traddr=192.168.8.1 live non-optimized
+- nvme6 tcp traddr=192.168.9.49,trsvcid=4420,host_traddr=192.168.9.1 live optimized
+- nvme7 tcp traddr=192.168.9.48,trsvcid=4420,host_traddr=192.168.9.1 live optimized

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

    Column
    # nvme netapp ontapdevices -o column

    Example output:

    Device        Vserver   Namespace Path
----------------------- ------------------------------
/dev/nvme0n1   vs_ol_nvme  /vol/ol_nvme_vol_1_1_0/ol_nvme_ns
/dev/nvme0n2   vs_ol_nvme  /vol/ol_nvme_vol_1_0_0/ol_nvme_ns
/dev/nvme0n3   vs_ol_nvme  /vol/ol_nvme_vol_1_1_1/ol_nvme_ns





NSID       UUID                                   Size
------------------------------------------------------------
1          72b887b1-5fb6-47b8-be0b-33326e2542e2   85.90GB
2          04bf9f6e-9031-40ea-99c7-a1a61b2d7d08   85.90GB
3          264823b1-8e03-4155-80dd-e904237014a4   85.90GB
    JSON
    # nvme netapp ontapdevices -o json

    Example output

    {
"ONTAPdevices" : [
    {
        "Device" : "/dev/nvme0n1",
        "Vserver" : "vs_ol_nvme",
        "Namespace_Path" : "/vol/ol_nvme_vol_1_1_0/ol_nvme_ns",
        "NSID" : 1,
        "UUID" : "72b887b1-5fb6-47b8-be0b-33326e2542e2",
        "Size" : "85.90GB",
        "LBA_Data_Size" : 4096,
        "Namespace_Size" : 20971520
    },
    {
        "Device" : "/dev/nvme0n2",
        "Vserver" : "vs_ol_nvme",
        "Namespace_Path" : "/vol/ol_nvme_vol_1_0_0/ol_nvme_ns",
        "NSID" : 2,
        "UUID" : "04bf9f6e-9031-40ea-99c7-a1a61b2d7d08",
        "Size" : "85.90GB",
        "LBA_Data_Size" : 4096,
        "Namespace_Size" : 20971520
      },
      {
         "Device" : "/dev/nvme0n3",
         "Vserver" : "vs_ol_nvme",
         "Namespace_Path" : "/vol/ol_nvme_vol_1_1_1/ol_nvme_ns",
         "NSID" : 3,
         "UUID" : "264823b1-8e03-4155-80dd-e904237014a4",
         "Size" : "85.90GB",
         "LBA_Data_Size" : 4096,
         "Namespace_Size" : 20971520
       },
  ]
}

Known issues

The NVMe-oF host configuration for OL 8.8 with ONTAP release has the following known issues:

NetApp Bug ID Title Description

1517321

Oracle Linux 8.8 NVMe-oF hosts create duplicate PDCs

On OL 8.8 NVMe-oF hosts, Persistent Discovery Controllers (PDCs) are created by passing the -p option to the nvme discover command. For a given initiator-target combination, each execution of the nvme discover command is expected to create one PDC. However, beginning with OL 8.x, NVMe-oF hosts create duplicate PDCs. This wastes resources on both the host and the target.