Known Issues


The following is a list of general limitations and known issues of the various components of this Mellanox OFED for Linux release.

For the list of old known issues, please refer to Mellanox OFED Archived Known Issues file at:

Internal Ref. Number



Description: IPoIB Tx queue may get stuck, leading to timeout warnings in dmesg and panic when toggling the interface.

Workaround: N/A

Keywords: IPoIB

Discovered in Release: 4.6-


Description: NVMe-oF driver of MLNX OFED v4.6-x.x.x.x does not function on SLES15 SP1 OSs, as SLES15 SP1 has a built-in NVME driver in the Linux image. Therefore, Mellanox NVME and NVME-oF drivers cannot be loaded.

Workaround: Use SLES15 SP0 instead.

Keywords: NVME-oF, NVME, SLES

Discovered in Release: 4.6-


Description: Innova cards do no support InfiniBand mode.

Workaround: N/A

Keywords: Innova, IB, InfiniBand

Discovered in Release: 4.6-


Description: OFED installation on XenServer OSs requires using the -u flag.

Workaround: N/A

Keywords: Installation, XenServer, OS, operating system

Discovered in Release: 4.6-


Description: A bonding bug found in Kernels 4.12 and 4.13 may cause a slave to become permanently stuck in BOND_LINK_FAIL state. As a result, the following message may appear in dmesg:

bond: link status down for interface eth1, disabling it in 100 ms

Workaround: N/A

Keywords: Bonding, slave

Discovered in Release: 4.6-


Description: Installing RHEL 7.6 OSs platform x86_64 and RHEL 7.6 ALT OSs platform PPCLE using YUM is not supported.

Workaround: Install these OSs using the mlnxofedinstall script.

Keywords: RHEL, RedHat, YUM, OS, operating system

Discovered in Release: 4.6-


Description: Ubuntu v16.04.05 and v16.04.05 OSs can only be used with Kernels of version 4.4.0-143 or below.

Workaround: N/A

Keywords: Ubuntu, Kernel, OS

Discovered in Release: 4.6-


Description: Uninstalling MLNX_OFED automatically results in the uninstallation of several libraries that are included in the MLNX_OFED package, such as InfiniBand-related libraries.

Workaround: If these libraries are required, reinstall them using the local package manager (yum/dnf).

Keywords: MLNX_OFED libraries

Discovered in Release: 4.6-


Description: Due to changes in libraries, MFT v4.11.0 and below are not forward compatible with MLNX_OFED v4.6- and above.

Therefore, with MLNX_OFED v4.6- and above, it is recommended to use MFT v4.12.0 and above.

Workaround: N/A

Keywords: MFT compatible

Discovered in Release: 4.6-


Description: On ConnectX-4 HCAs, GID index for RoCE v2 is inconsistent when toggling between enabled and disabled interface modes.

Workaround: N/A

Keywords: RoCE v2, GID

Discovered in Release: 4.6-


Description: MLNX_OFED v4.6 YUM and Zypper installations fail on RHEL8.0, SLES15.0 and PPCLE OSs.

Workaround: N/A

Keywords: YUM, Zypper, installation, RHEL, RedHat, SLES, PPCLE

Discovered in Release: 4.6-


Description: On kernels 4.10-4.14, MTUs larger than 1500 cannot be set for a GRE interface with any driver (IPv4 or IPv6).

Workaround: Upgrade your kernel to any version higher than v4.14.

Keywords: Fedora 27, gretap, ip_gre, ip_tunnel, ip6_gre, ip6_tunnel

Discovered in Release: 4.6-


Description: Driver reload takes several minutes when a large number of VFs exists.

Workaround: N/A

Keywords: VF, SR-IOV

Discovered in Release: 4.6-


Description: Cannot set max Tx rate for VFs from the ARM.

Workaround: N/A

Keywords: Host control, max Tx rate

Discovered in Release: 4.6-


Description: Software counters not working for representor net devices.

Workaround: N/A

Keywords: mlx5, counters, representors

Discovered in Release: 4.6-


Description: Running heavy traffic (such as 'ping flood') while bringing up and down other mlx5 interfaces may result in “INFO: rcu_preempt dectected stalls on CPUS/tasks:” call traces.

Workaround: N/A

Keywords: mlx5

Discovered in Release: 4.6-


Description: Get/Set Forward Error Correction FEC configuration is not supported on ConnectX-6 HCAs with 200Gbps speed rate.

Workaround: N/A

Keywords: Forward Error Correction, FEC, 200Gbps

Discovered in Release: 4.6-


Description: Mellanox Firmware Tools (MFT) package is missing from Ubuntu v18.04.2 OS.

Workaround: Manually install MFT.

Keywords: MFT, Ubuntu, operating system

Discovered in Release: 4.6-


Description: On ConnectX-3 and ConnectX-3 Pro HCAs, CR-Dump poll is not supported using sysfs commands.

Workaround: If supported in your Kernel, use the devlink tool as an alternative to sysfs to achieve CR-Dump support.

Keywords: mlx4, devlink, CR-Dump

Discovered in Release: 4.6-


Description: When attempting to destroy IPoIB bonding interface on PPCLE setups, a leak of resources might occur.

Workaround: N/A

Keywords: IPoIB, bonding, PPCLE

Discovered in Release: 4.6-


Description: On ConnectX-6 HCAs and above, an attempt to configure advertisement (any bitmap) will result in advertising the whole capabilities.

Workaround: N/A

Keywords: 200Gmbps, advertisement, Ethtool

Discovered in Release: 4.6-


Description: eIPoIB with OVS is currently not functional.

Workaround: N/A

Keywords: eIPoIB

Discovered in Release: 4.5-


Description: HW LRO feature is disabled OOB, which results in increased CPU utilization on the Receive side. On ConnectX-5 adapter cards and above, this causes a bandwidth drop for a few streams.

Workaround: Make sure to enable HW LRO in the driver:

ethtool -k <intf> lro

ethtool --set-priv-flag <intf> hw_lro on

Keywords: HW LRO, ConnectX-5 and above

Discovered in Release: 4.5-


Description: MPI package is not part of MLNX_OFED package in Fedora 28 OS.

Workaround: Manually install MPI package.

Keywords: MPI package, Fedora

Discovered in Release: 4.5-


Description: Attempting to allocate an excessive number of VFs per PF in operating systems with kernel versions below v4.15 might fail due to a known issue in the Kernel.

Workaround: Make sure to update the Kernel version to v4.15 or above.

Keywords: VF, PF, IOMMU, Kernel, OS

Discovered in Release: 4.5-


Description: NEO-Host is not supported on the following OSs:

  • SLES12 SP3

  • SLES12 SP4

  • SLES15

  • Fedora 28

  • RHEL7.1

  • RHEL7.4 ALT (Pegas1.0)

  • REL 7.5

  • RHEL7.6

  • XenServer 4.9

Workaround: N/A

Keywords: NEO-Host, operating systems

Discovered in Release: 4.5-


Description: On SLES 12 SP1 OSs, a kernel tracepoint issue may cause undefined behavior when inserting a kernel module with a wrong parameter.

Workaround: N/A

Keywords: mlx5 driver, SLES 12 SP1

Discovered in Release: 4.5-


Description: When using ConnectX-5 with LRO over PPC systems, the HCA might experience back pressure due to delayed PCI Write operations. In this case, bandwidth might drop from line-rate to ~35Gb/s. Packet loss or pause frames might also be observed.

Workaround: Look for an indication of PCI back pressure (“outbound_pci_stalled_wr” counter in ethtools advancing). Disabling LRO helps reduce the back pressure and its effects.

Keywords: Flow Control, LRO

Discovered in Release: 4.4-


Description: On RHEL v7.3, 7.4 and 7.5 OSs, setting IPv4-IP-forwarding will turn off LRO on existing interfaces. Turning LRO back on manually using ethtool and adding a VLAN interface may cause a warning call trace.

Workaround: Make sure IPv4-IP-forwarding and LRO are not turned on at the same time.

Keywords: IPv4 forwarding, LRO

Discovered in Release: 4.4-


Description: Reconfiguring bridge interfaces while traffic is running from the virtual machine to the Hypervisor may lead to packet loss for up to 20 seconds.

Workaround: N/A

Keywords: eIPoIB

Discovered in Release: 4.4-


Description: Virtual machine network outage (for up to 10 seconds) is expected during live migration due to topology discovery.

Workaround: N/A

Keywords: eIPoIB

Discovered in Release: 4.4-


Description: When working in IPoIB ULP (non-enhanced) mode, IPv6 may disappear in case ring size is changed dynamically (while the driver is running).

Workaround: There are three workarounds for this issue:

  • Perform static configuration of ring size instead of dynamic configuration

  • In case you have run dynamic configuration, run ifdown ifup afterwards

  • On supported kernels, enable keep_addr_on_down IPv6 sysfs parameter before configuring the ring size dynamically

Keywords: IPoIB, ULP mode, ring size

Discovered in Release: 4.4-


Description: Software reset may result in an order inversion of interface names.

Workaround: Restart the driver to reset the order.

Keywords: Software reset

Discovered in Release: 4.4-


Description: Retpoline support in GCC causes an increase in CPU utilization, which results in IP forwarding’s 15% performance drop.

Workaround: N/A

Keywords: Retpoline, GCC, CPU, IP forwarding, Spectre attack

Discovered in Release: 4.4-


Description: When working with old kernel versions that do not include the unregister_netdevice_notifier function fix (introduced in “net: In unregister_netdevice_notifier unregister the netdevices” commit), reloading ib_ipoib module using modprobe will fail with the following error message: “ Cannot allocate memory ”.

Workaround: Reload the driver instead of modprobe by running:

/etc/init.d/openibd restart

Keywords: IPoIB

Discovered in Release: 4.4-


Description: On SLES 11 SP3 PPC64 OSs, a memory allocation issue may prevent the interface from loading after reboot, resulting in a call trace in the message log.

Workaround: Restart the driver.

Keywords: SLES11 SP3

Discovered in Release: 4.4-


Description: MLNX_OFED cannot be installed on SLES 15 OSs using Zypper repository.

Workaround: Install MLNX_OFED using the standard installation script instead of Zypper repository.

Keywords: Installation, SLES, Zypper

Discovered in Release: 4.4-


Description: When working with ConnectX-4/ConnectX-5 HCAs on PPC systems with Hardware LRO and Adaptive Rx support, bandwidth drops from full wire speed (FWS) to ~60Gb/s.

Workaround: Make sure to disable Adaptive Rx when enabling Hardware LRO: ethtool -C <interface> adaptive-rx off

ethtool -C <interface> rx-usecs 8 rx-frames 128

Keywords: Hardware LRO, Adaptive Rx, PPC

Discovered in Release: 4.3-


Description: NVMEoF protocol does not support LBA format with non-zero metadata size. Therefore, NVMe namespace configured to LBA format with metadata size bigger than 0 will cause Enhanced Error Handling (EEH) in PowerPC systems.

Workaround: Configure the NVMe namespace to use LBA format with zero sized metadata.

Keywords: NVMEoF, PowerPC, EEH

Discovered in Release: 4.3-


Description: In switchdev mode, the IB device exposed does not support MADs. As a result, tools such as ibstat that work with MADs will not function properly.

Workaround: N/A

Keywords: switchdev, IB representors, mlx5, MADs

Discovered in Release: 4.3-


Description: In switchdev mode default configuration, stateless offloads/steering based on inner headers is not supported.

Workaround: To enable stateless offloads/steering based on inner headers, disable encap by running:

devlink dev eswitch show pci/0000:83:00.1 encap disable

Or, in case devlink is not supported by the kernel, run:

echo none > /sys/kernel/debug/mlx5/<BDF>/compat/encap

Note: This is a hardware-related limitation.

Keywords: switchdev, stateless offload, steering

Discovered in Release: 4.3-


Description: ConnectX-5 supports up to 62 IB representors. When attempting to move to switchdev mode where more than 62 VFs are initialized, the call will fail with the following error message:

devlink answers: Invalid argument

Workaround: N/A

Keywords: ConnectX-5, IB representors

Discovered in Release: 4.3-


Description: When setting a non-default IPv6 link local address or an address that is not based on the device MAC, connection establishments over RoCEv2 might fail.

Workaround: N/A

Keywords: IPV6, RoCE, link local address

Discovered in Release: 4.3-


Description: In RoCE LAG mode, when running ibdev2netdev -v , the port state of the second port of the mlx4_0 IB device will read “NA” since this IB device does not have a second port.

Workaround: N/A

Keywords: mlx4, RoCE LAG, ibdev2netdev, bonding

Discovered in Release: 4.3-


Description: PKEY interface receives PTP delay requests without a time-stamp.

Workaround: Run ptp4l over the parent interface.

Keywords: PKEY, PTP

Discovered in Release: 4.3-


Description: Number of MSI-X that can be allocated for VFs and PFs in total is limited to 2300 on Power9 platforms.

Workaround: N/A

Keywords: MSI-X, VF, PF, PPC, SR-IOV

Discovered in Release: 4.3-


Description: Firmware reset might cause Enhanced Error Handling (EEH) on Power7 platforms.

Workaround: N/A

Keywords: EEH, PPC

Discovered in Release: 4.3-


Description: On Fedora 20 operating systems, driver load fails with an error message such as: “ [185.262460] kmem_cache_sanity_check (fs_ftes_0000:00:06.0): Cache name already exists.

This is caused by SLUB allocators grouping multiple slab kmem_cache_create into one slab cache alias to save memory and increase cache hotness. This results in the slab name to be considered stale.

Workaround: Upgrade the kernel version to kernel-3.19.8-100.fc20.x86_64.

Note that after rebooting to the new kernel, you will need to rebuild

MLNX_OFED against the new kernel version.

Keywords: Fedora, driver load

Discovered in Release: 4.3-


Description: When running perftest (ib_send_bw, ib_write_bw, etc.) in rdma-cm mode, the resp_cqe_error counter under /sys/class/infiniband/mlx5_0/ports/1/hw_counters/resp_cqe_error might increase. This behavior is expected and it is a result of receive WQEs that were not consumed.

Workaround: N/A

Keywords: perftest, RDMA CM, mlx5

Discovered in Release: 4.3-


Description: Traffic may hang while working in IPoIB SR-IOV environment.

Workaround: N/A

Keywords: IPoIB, SR-IOV

Discovered in Release: 4.3-


Description: Due to Enhanced IPoIB’s lack of priority-based flow control, PTP accuracy may adversely be affected by heavy TCP traffic.

Workaround: N/A

Keywords: Enhanced IPoIB, PTP

Discovered in Release: 4.3-


Description: Configuring SR-IOV after disabling RoCE LAG using sysfs (/sys/bus/pci/drivers/mlx5_core//roce_lag_enable) might result in RoCE LAG being enabled again in case SR-IOV configuration fails.

Workaround: Make sure to disable RoCE LAG once again.

Keywords: RoCE LAG, SR-IOV

Discovered in Release: 4.3-


Description: On RHEL7.4, due to an OS issue introduced in kmod package version 20-15.el7_4.6, parsing the depmod configuration files will fail, resulting in either of the following issues:

  • Driver restart failure prompting an error message, such as: “ ERROR: Module mlx5_core belong to kernel which is not a part of MLNX_OFED, skipping...

  • nvmet_rdma kernel module dysfunction, despite installing MLNX_OFED using the "--with-nvmf " option. An error message, such as: “ nvmet_rdma: unknown parameter 'offload_mem_start' ignored ” will be seen in dmesg output

Workaround: Go to RedHat webpage to upgrade the kmod package version.

Keywords: driver restart, kmod, kmp, nvmf, nvmet_rdma

Discovered in Release: 4.2-


Description: Changing IPoIB Tx/Rx ring size dynamically using ethtool is not permitted.

Workaround: Use the send_queue_size/recv_queue_size module parameters to change the Tx/Rx ring size.

Keywords: IPoIB, queue size

Discovered in Release: 4.2-


Description: On vRedHat 7.2 operating systems, when Network Manager is enabled, IPoIB interfaces may not get an IPv6 address due to an issue in the Network Manager.

Workaround: Disable Network Manager or upgrade its version.

Keywords: Network Manager, IPoIB, IPv6

Discovered in Release: 4.2-


Description: Packet Size (Actual Packet MTU) limitation for IPsec offload on Innova IPsec adapter cards: The current offload implementation does not support IP fragmentation. The original packet size should be such that it does not exceed the interface's MTU size after the ESP transformation (encryption of the original IP packet which increases its length) and the headers (outer IP header) are added:

  • Inner IP packet size <= I/F MTU - ESP additions (20) - outer_IP (20) - fragmentation issue reserved length (56)

  • Inner IP packet size <= I/F MTU - 96

This mostly affects forwarded traffic into smaller MTU, as well as UDP traffic. TCP does PMTU discovery by default and clamps the MSS accordingly.

Workaround: N/A

Keywords: Innova IPsec, MTU

Discovered in Release: 4.2-


Description: No LLC/SNAP support on Innova IPsec adapter cards.

Workaround: N/A

Keywords: Innova IPsec, LLC/SNAP

Discovered in Release: 4.2-


Description: No support for FEC on Innova IPsec adapter cards. When using switches, there may be a need to change its configuration.

Workaround: N/A

Keywords: Innova IPsec, FEC

Discovered in Release: 4.2-


Description: Heavy traffic may cause SYN flooding when using Innova IPsec adapter cards.

Workaround: N/A

Keywords: Innova IPsec, SYN flooding

Discovered in Release: 4.2-


Description: Priority Based Flow Control is not supported on Innova IPsec adapter cards.

Workaround: N/A

Keywords: Innova IPsec, Priority Based Flow Control

Discovered in Release: 4.2-


Description: Pause configuration is not supported when using Innova IPsec adapter cards. Default pause is global pause (enabled).

Workaround: N/A

Keywords: Innova IPsec, Global pause

Discovered in Release: 4.2-


Description: Connecting and disconnecting a cable several times may cause a link up failure when using Innova IPsec adapter cards.

Workaround: N/A

Keywords: Innova IPsec, Cable, link up

Discovered in Release: 4.2-


Description: On Innova IPsec adapter cards, supported MTU is between 512 and 2012 bytes. Setting MTU values outside this range might fail or might cause traffic loss.

Workaround: Set MTU between 512 and 2012 bytes.

Keywords: Innova IPsec, MTU

Discovered in Release: 4.2-


Description: If OpenSM version is 4.8.1 and below, the IB interfaces link remains Down while the "SRIOV_IB_ROUTING_MODE_P1=1" and "SRIOV_IB_ROUTING_MODE_P2=1" flags are enabled in the HCA.

Workaround: N/A

Keywords: OpenSM, SR-IOV, IB link

Discovered in Release: 4.2-


Description: On kernel versions 4.10-4.13, when resetting sriov_numvfs to 0 on PowerPC systems, the following dmesg warning will appear:

mlx5_core <BDF>: can't update enabled VF BAR0

Workaround: Reboot the system to reset sriov_numvfs value.

Keywords: SR-IOV, numvfs

Discovered in Release: 4.2-


Description: In old kernel versions, such as Ubuntu 14.04 and RedHat 7.1, VXLAN interface does not reply to ARP requests for a MAC address that exists in its own ARP table. This issue was fixed in the following newer kernel versions: Ubuntu 16.04 and RedHat 7.3.

Workaround: N/A

Keywords: ARP, VXLAN

Discovered in Release: 4.2-


Description: Connecting multiple ports on the same server to the same subnet (IP/IB) will cause all interfaces connected to that subnet to respond to ARP requests. As a result, wrong ARP replies might be received when trying to resolve IP addresses.

Workaround: Run the following to make sure only the interface with the requested IP address responds to the ARP request:

sysctl -w net.ipv4.conf.all.arp_ignore=1

Keywords: IPoIB, librdmacm, ARP

Discovered in Release: 4.2-


Description: When using kernel versions older than version 4.7 with IOMMU enabled, performance degradations and logical issues (such as soft lockup) might occur upon high load of traffic. This is caused due to the fact that IOMMU IOVA allocations are centralized, requiring many synchronization operations and high locking overhead amongst CPUs.

Workaround: Use kernel v4.7 or above, or a backported kernel that includes the following patches:

  • 2aac630429d9 iommu/vt-d: change intel-iommu to use IOVA frame numbers

  • 9257b4a206fc iommu/iova: introduce per-cpu caching to iova allocation

  • 22e2f9fa63b0 iommu/vt-d: Use per-cpu IOVA caching

Keywords: IOMMU, soft lockup

Discovered in Release: 4.2-


Description: On 64k page size setups, DMA memory might run out when trying to increase the ring size/number of channels.

Workaround: Reduce the ring size/number of channels.

Keywords: DMA, 64K page

Discovered in Release: 4.2-


Description: When configuring VF VST, VLAN-tagged outgoing packets will be dropped in case of ConnectX-4 HCAs. In case of ConnectX-5 HCAs, VLAN-tagged outgoing packets will have another VLAN tag inserted.

Workaround: N/A

Keywords: VST

Discovered in Release: 4.2-


Description: On Passthrough/VM machines with relatively old QEMU and libvirtd,

CMD timeout might occur upon driver load.

After timeout, no other commands will be completed and all driver operations will be stuck.

Workaround: Upgrade the QEMU and libvirtd on the KVM server.

Tested with (Ubuntu 16.10) are the following versions:

  • libvirt 2.1.0

  • QEMU 2.6.1

Keywords: QEMU

Discovered in Release: 4.2-


Description: Using dm-multipath for High Availability on top of NVMEoF block devices must be done with “directio” path checker.

Workaround: N/A

Keywords: NVMEoF

Discovered in Release: 4.2-


Description: RedHat v7.3 PPCLE and v7.4 PPCLE operating systems do not support KVM qemu out of the box. The following error message will appear when attempting to run virt-install to create new VMs:

Cant find qemu-kvm packge to install

Workaround: Acquire the following rpms from the beta version of 7.4ALT to 7.3/7.4 PPCLE (in the same order):

  • qemu-img-.el7a.ppc64le.rpm

  • qemu-kvm-common-.el7a.ppc64le.rpm

  • qemu-kvm-.el7a.ppc64le.rpm

Keywords: Virtualization, PPC, Power8, KVM, RedHat, PPC64LE

Discovered in Release: 4.2-


Description: A soft lockup in the CQ polling flow might occur when running very high stress on the GSI QP (RDMA-CM applications). This is a transient situation from which the driver will later recover.

Workaround: N/A

Keywords: RDMA-CM, GSI QP, CQ

Discovered in Release: 4.2-


Description: When running Network Manger on devices on which Enhanced IPoIB is enabled, CONNECTED_MODE can only be set to NO/AUTO. Setting it to YES will prevent the interface from being configured.

Workaround: N/A

Keywords: Enhanced IPoIB, network manager, connected_mode

Discovered in Release: 4.2-


Description: When working in RoCE LAG over kernel v3.10, a kernel crash might occur when unloading the driver as the Network Manager is running.

Workaround: Stop the Network Manager before unloading the driver and start it back once the driver unload is complete.

Keywords: RoCE LAG, network manager

Discovered in Release: 4.2-


Description: When setting VGT+, the maximal number of allowed VLAN IDs presented in the sysfs is 813 (up to the first 813).

Workaround: N/A

Keywords: VGT+

Discovered in Release: 4.2-


Description: On Arm setups, DMA memory resource is limited due to a default CMA limitation.

Workaround: Increase the CMA limitation or cancel its use, using the kernel's CMD line parameters:

  • Add the parameter cma=256M to increase the CMA limit to 256MB

  • Add the parameter cma=0 to disable the use of CMA

Keywords: IPoIB, CMA

Discovered in Release: 4.2-


Description: On SLES11 SP1 operating system, IPoIB interface renaming process may fail due to a broken udev rule, leaving interfaces with names like ib0_rename.


  1. Open the udev conf file "/etc/udev/rules.d/70-persistent-net.rules", and remove such lines as SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", =="" , NAME="eth0".

  2. Reload the driver stack.

Keywords: IPoIB

Discovered in Release: 4.2-


Description: Lustre support is limited to versions 2.9 and 2.10.

Workaround: N/A

Keywords: Lustre

Discovered in Release: 4.1-


Description: NVMEoF support is available for the following:

  • SLES 12.3 and above

  • RHEL 7.2 and above (Host side only)

  • RHEL 7.4 and above (Host and Target side)

  • OS with distribution/custom kernel >= 4.8.x

Workaround: N/A

Keywords: NVMEoF Host/Target


Description: In kernels below v4.13, connection between NVMEoF host and target cannot be established in a hyper-threaded system with more than 1 socket.

Workaround: On the host side, connect to NVMEoF subsystem using --nr-io-queues <num_queues> flag.

Note that num_queues must be lower or equal to num_sockets multiplied with num_cores_per_socket.

Keywords: NVMEoF


Description: Enabling multiple namespaces per subsystem while using NVMEoF target offload is not supported.

Workaround: To enable more than one namespace, create a subsystem for each one.

Keywords: NVMEoF Target Offload, namespace


Description: Ethtool -i displays incorrect driver name for devices with enhanced IPoIB support.

Workaround: N/A

Keywords: Enhanced IPoIB, Ethtool


Description: PKEY-related limitations in enhanced IPoIB:

  • Since the parent interface ib<x> and the child interface ib<x>.yyyy share the same receive resources, the parent interface’s MTU cannot be less than the child interface’s MTU

  • Interface counters and Ethtool control are not supported on child interfaces

  • Parent interface should be in UP state to enable child interface to receive traffic

Workaround: N/A

Keywords: PKEY, Enhanced IPoIB, MTU, Ethtool, Interface Counters


Description: When Enhanced IPoIB is enabled, the following module parameters will not be functional:

  • send_queue_size

  • recv_queue_size

  • max_nonsrq_conn_qp

Workaround: N/A

Keywords: Enhance IPoIB


Description: Creating virtual functions on a device that is in LAG mode will destroy the LAG configuration. The boding device over the Ethernet NICs will continue to work as expected.

Workaround: N/A

Keywords: LAG, SR-IOV


Description: When node GUID of a device is set to zero (0000:0000:0000:0000), RDMA_CM user space application may crash.

Workaround: Set node GUID to a nonzero value.

Keywords: RDMA_CM


Description: Since enhanced IPoIB does not support connected mode on RedHat operating systems, when using network manger and enhanced IPoIB capable devices, CONNECTED_MODE must be set to NO/AUTO.

Setting CONNECTED_MODE to yes will cause the interface to not be configured.

Workaround: N/A

Keywords: Enhanced IPoIB


Description: When enhanced IPoIB mode is enabled, ring size limit is 8k. When it is disabled, ring size limit is decreased to 4k.

Workaround: N/A

Keywords: Enhanced IPoIB


Description: New versions of iproute which support new kernel features may misbehave on old kernels that do not support these new features.

Workaround: N/A

Keywords: iproute


Description: When working on Xenserver hypervisor with SR-IOV enabled on it, make sure the following instructions are applied:

  1. Right after enabling SR-IOV, unbind all driver instances of the virtual functions from their PCI slots.

  2. It is not allowed to unbind PF driver instance while having active VFs.

Workaround: N/A

Keywords: SR-IOV


Description: A soft lockup in the CQ polling flow might occur when running very high stress on the GSI QP (RDMA-CM applications). This is a transient situation and the driver recovers from it after a while.

Workaround: N/A

Keywords: RDMA-CM


Description: Creating a PKEY interface using “ ip link ” is not supported.

Workaround: Use sysfs to create a PKEY interface.

Keywords: IPoIB, PKEY


Description: Displaying multicast groups using sysfs may not show all the entries on Fedora 23 OS.

Workaround: N/A

Keywords: IPoIB


Description: Upgrading from MLNX_OFED v3.x to v4.x using yum and apt-get repositories fails.

Workaround: Remove MLNX_OFED v3.x using the script, and only then install MLNX_OFED v4.x as usual.

Keywords: Installation


Description: When using ConnectX-5 adapter cards, the following error might be printed to dmesg, indicating temporary lack of DMA pages:

“mlx5_core ... give_pages:289:(pid x): Y pages alloc time exceeded the max permitted duration

mlx5_core ... page_notify_fail:263:(pid x): Page allocation failure notification on func_id(z) sent to fw

mlx5_core ... pages_work_handler:471:(pid x): give fail -12”

Example: This might happen when trying to open more than 64 VFs per port.

Workaround: N/A

Keywords: mlx5_core, DMA


Description: Performing some operations on the user end during reboot might cause call trace/panic, due to bugs found in the Linux kernel.

For example: Running get_vf_stats (via iptool) during reboot.

Workaround: N/A

Keywords: mlx5_core, reboot


Description: Mounting MLNX_OFED to a path that contains special characters, such as parenthesis or spaces is not supported. For example, when mounting MLNX_OFED to “/media/CDROM(vcd)/”, installation will fail and the following error message will be displayed:

# cd /media/CDROM\(vcd\)/

# ./mlnxofedinstall

sh: 1: Syntax error: "(" unexpected

Workaround: N/A

Keywords: Installation


Description: When offload traffic sniffer is on, the bandwidth could decrease up to 50%.

Workaround: N/A

Keywords: Offload Traffic Sniffer


Description: On kernels below v4.2, when removing a bonding module with devices different from ARPHRD_ETHER, a call trace may be received.

Workaround: Remove the bond in the following order:

Remove the slaves, delete the bond, and only then remove the bonding module.

Keywords: Bonding


Description: Soft RoCE does not support Extended Reliable Connection (XRC).

Workaround: N/A

Keywords: Soft RoCE, XRC


Description: In ConnectX-3, when using a server with page size of 64K, the UAR BAR will become too small. This may cause one of the following issues:

  1. mlx4_core driver does not load.

  2. The mlx4_core driver does load, but calls to ibv_open_device may return ENOMEM errors.


  1. Add the following parameter in the firmware's ini file under [HCA] section: log2_uar_bar_megabytes = 7

  2. Re-burn the firmware with the new ini file.

Keywords: PPC


Description: On several OSs, setting a number of TC is not supported via the tc tool.

Workaround: Set the number of TC via the /sys/class/net//qos/tc_num sysfs file.

Keywords: Ethernet, TC


Description: An issue in InfiniBand bond interfaces may cause memory corruption in Ubuntu v14.04 and v14.10 OSs.

The memory corruption happens when attempting to reload the driver while the bond is up with InfiniBand salves.

Workaround: Delete the bond before restarting the driver.

Keywords: Bonding, IPoIB


Description: Soft RoCE counters located under /sys/class/infiniband//ports/1/counters/ directory are not supported.

Workaround: N/A

Keywords: Soft RoCE


Description: Only the following two experimental verbs are supported for Soft RoCE:

  • ibv_exp_query_device

  • ibv_exp_poll_cq.

Workaround: N/A

Keywords: Soft RoCE


Description: When setting IOMMU=ON, a severe performance degradation may occur due to a bug in IOMMU.

Workaround: Make sure the following patches are found in your kernel:

  • iommu/vt-d: Fix PASID table allocation

  • iommu/vt-d: Fix IOMMU lookup for SR-IOV Virtual Functions

Note: These patches are already available in Ubuntu 16.04.02 and 17.04 OSs.

Keywords: Performance, IOMMU


Description: rdma_cm running over IB ports does not support UD QPs on ConnectX-3 adapter cards.

Workaround: N/A

Keywords: SR-IOV, RDMA CM


Description: In RoCE LAG over ConnectX-4 adapter cards, the script ibdev2netdev may show a wrong port state for the bonded device. This means that although the IB device/port mlx5_bond_0/1 is up (as seen in ibstat), ibdev2netdev may report that it is down.

Workaround: N/A

Keywords: RoCE, LAG, bonding

Description: Can’t set max TX rate for VFs from the ARM

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