Ins & Outs

In a previous post, I wrote the first part of my experience to install infiniband adapters on a gentoo cluster.  Recently, I upgraded the system and found i forgot the details of the installation and setup.  So I need to write down what i have done.

Step 1: Turn on the infiniband modules in the kernel as discussed in the previous post.

Step 2:  Emerge necessary packages.  They were in the science layer, but now (July 2011) moved to the main tree under sys-infiniband category.  On my cluster system,  the following packages were installed.


sys-infiniband/dapl-2.0.32
sys-infiniband/infiniband-diags-1.5.8
sys-infiniband/libibcm-1.0.5
sys-infiniband/libibcommon-1.1.2_p20090314
sys-infiniband/libibmad-1.3.7
sys-infiniband/libibumad-1.3.7
sys-infiniband/libibverbs-1.1.4
sys-infiniband/libipathverbs-1.2
sys-infiniband/libmlx4-1.0.1
sys-infiniband/libmthca-1.0.5-r2
sys-infiniband/libnes-1.1.1
sys-infiniband/librdmacm-1.0.14.1
sys-infiniband/libsdp-1.1.108
sys-infiniband/openib-1.4
sys-infiniband/openib-files-1.5.3.1
sys-infiniband/opensm-3.3.9
sys-infiniband/perftest-1.3.0


Step 3:   Edit configuration file, /etc/infiniband/openib.conf. The following is the content of my configuration file.


# Start HCA driver upon boot
ONBOOT=yes

# Load VNIC module
#VNIC_LOAD=yes


Step 4:  Edit the init.d script, /etc/init.d/openib. This is the important part.  The original one seems does not load all necessary modules  or in the right order. After all the if-clauses for setting POST_LOAD_MODULES, change the following:

PRE_UNLOAD_MODULES="ib_rds ib_ucm kdapl ib_srp_target scsi_target ib_srp ib_iser ib_sdp rdma_ucm rdma_cm ib_addr ib_cm ib_local_sa findex"
POST_UNLOAD_MODULES="$PRE_UNLOAD_MODULES ib_ipoib ib_sa ib_uverbs ib_umad"

to the following (pay attention to those in bold fonts):

#Xianlong Wang
# svcrdma: server-side module for NFS/RDMA
# xprtrdma: client-side module for NFS/RDMA

In the start() function, after einfo "Loading HCA and Access Layer drivers", add the following to load the necessary modules:


# Xianlong Wang, hard-coded
if [[ "${MLX4_LOAD}" == "yes" ]]; then
/sbin/modprobe mlx4_core > /dev/null 2>&1
rc=$[ $rc + $? ]
/sbin/modprobe mlx4_ib > /dev/null 2>&1
rc=$[ $rc + $? ]
/sbin/modprobe mlx4_en > /dev/null 2>&1
rc=$[ $rc + $? ]

fi


Step 4: add the init.d scripts, openib and opensm to boot level.

rc-update add openib default
rc-update add opensm default


Step 5: Edit the /etc/conf.d/net file for IPoverIB settings. Create the symbolic link /etc/init.d/net.ib0 to /etc/init.d/net.lo.

config_ib0=("10.0.0.1/24")
routes_ib0=("default via 10.0.0.1")
nis_domain_ib0="abc"
nis_servers_ib0="10.0.0.1"

Then add net.ib0 to default run level.

rc-update add net.ib0 default


After rebooting, check the port status by running ibstatus. The following output is given:

Infiniband device 'mlx4_0' port 1 status:
default gid: fe80:0000:0000:0000:f04d:a290:9778:efbd
base lid: 0x1
sm lid: 0x6
state: 4: ACTIVE
phys state: 5: LinkUp
rate: 40 Gb/sec (4X QDR)
link_layer: InfiniBand

Using ifconfig to check the ip address. The following output is given.

ib0 Link encap:InfiniBand HWaddr 80:00:00:48:FE:80:00:00:00:00:00:00:00:00:00:00:00:00:00:00
inet addr:10.0.0.1 Bcast:10.0.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:2044 Metric:1
RX packets:43233 errors:0 dropped:0 overruns:0 frame:0
TX packets:44438 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:256
RX bytes:5280799 (5.0 MiB) TX bytes:2771849 (2.6 MiB)

Still is there a problem. ibv_devinfo outputs the following error message.

mlx4: There is a mismatch between the kernel and the userspace libraries: Kernel does not support XRC. Exiting.
Failed to open device


My college recently purchased a Dell M610 cluster and I am in charge for the administration job.  The cluster consists of 8 nodes and each node has two 1Gb Ethernet cards and one Infiniband card(? or whatever it should be called).  The nodes are connected with two back-pane Dell PowerConnect 6220 ethernet switch and one Mellanox M3601Q switch on the chassis.  The Infiniband switch does not come with subnet management.

I decide to choose Gentoo as the base system for a clean and slim installation, particularly the meta-package administration system, portage, is a great attraction.  Basic system installation is no problem and Ethernet cards setup is easy. But Infiniband is a big trouble at the beginning because the OFED package from either Mellanox or OpenFabrics only supports Redhat and SUSE linux boxes.  There is no much documentation available and all the packages are rpm packages… Official portage build does not include any Infiniband packages. Gentoo-science overlay has a category sys-infiniband, but it seems they are not well curated and many issues. I spent quite a lot of time to figure out a solution..  Here I record what I did for the future reference and someone who might encounter the same problem.

Step 1 : check the hardware information

lspci

Information regards to the infiniband is as follows:

04:00.0 InfiniBand: Mellanox Technologies MT26428 [ConnectX VPI PCIe 2.0 5GT/s – IB QDR / 10GigE] (rev b0)

check if it is supported by the linux kernel at http://kmuto.jp/debian/hcl/.

It is supported for kernel v2.6.25- and use “mlx4_core” driver.

Step 2: kernel compilation

I use the gentoo kernel source 2.6.34-gentoo-r12.  Other versions higher than 2.6.25 should be fine, I assume.

a)  Device Drivers -> set “Infiniband support” as module.  Under “Infiniband support”, set the following ones as module, “Infiniband userspace MAD support, Infiniband userspace access (verbs and CM), Mellanox ConnectX HCA support, IP-over-Infiniband, Infiniband SCSI RDMA Protocol, iSCSI Extensions for RDMA (iser)”.  Set “IP-over-InfiniBand Connected Mode Support” as built-in.  For other Infiniband cards, choose other drivers than “Mellanox ConnectX HCA”

b)  Device Drivers -> Network device support: set Ethernet (10000 Mbit) (Gigabit Eternet card has already been configured).  Set “Mellanox Technologies ConnectX 10G support” as module. This provides the driver, mlx4_en.

c) run “make && make modules_install” to compile the kernel.

So far, we have a ready kernel.  After rebooting, using the command, lsmod, you should see “mlx4_core” being loaded.