How to check Fibre Channel HBAs in Linux

Step-1: Determine the Manufacturer and Model of the HBAs.

Run the lspci command to list all PCI cards detected on the system.

# lspci | grep "Fibre Channel"
07:00.0 Fibre Channel: QLogic Corp. ISP2532-based 8Gb Fibre Channel to PCI Express HBA (rev 02)
0a:00.0 Fibre Channel: QLogic Corp. ISP2532-based 8Gb Fibre Channel to PCI Express HBA (rev 02)

The above output shows the system bus has detected two QLogic HBAs.

Step-2: Get the Vendor and Device IDs for the HBAs installed.

These can be obtained from the file /usr/share/hwdata/pci.ids

# vi /usr/share/hwdata/pci.ids
.....
1077  QLogic Corp.
 2532  ISP2532-based 8Gb Fibre Channel to PCI Express HBA
.....

The vendor id for QLogic is 1077 and the device id is 2532. You could confirm this using the lspci -nn command as shown below

# lspci -nn | grep "Fibre Channel"
07:00.0 Fibre Channel [0c04]: QLogic Corp. ISP2532-based 8Gb Fibre Channel to PCI Express HBA [1077:2532] (rev 02)
0a:00.0 Fibre Channel [0c04]: QLogic Corp. ISP2532-based 8Gb Fibre Channel to PCI Express HBA [1077:2532] (rev 02)

Step-3: Check if the driver modules are installed.

This can be done by searching the list of available modules. (Replace 2.6.18-308.el5PAE with your kernel version in the command below)

# grep 1077 /lib/modules/2.6.18-308.el5PAE/modules.* | grep 2532
/lib/modules/2.6.18-308.el5PAE/modules.alias:alias pci:v00001077d00002532sv*sd*bc*sc*i* qla2xxx
/lib/modules/2.6.18-308.el5PAE/modules.pcimap:qla2xxx              0x00001077 0x00002532 0xffffffff 0xffffffff 0x00000000 0x00000000 0x0

The above output shows that this HBA is supported by the module qla2xxx

Step-4: Check if the drivers for these HBAs are loaded in the kernel.

The lsmod command will list the currently loaded kernel modules

# lsmod | grep qla2xxx
qla2xxx              1205905  0
scsi_transport_fc      44745  1 qla2xxx
scsi_mod              144277  16 be2iscsi, ib_iser, iscsi_tcp, bnx2i, libcxgbi, libiscsi2, scsi_transport_iscsi2, scsi_dh, sr_mod, sg, usb_storage, qla2xxx, scsi_transport_fc, libata,cciss, sd_mod

The output shows the module qla2xxx is loaded by the kernel. If you don't see any output for lsmod command then you can load the module using modprobe command

# modprobe -v qla2xxx

Step-5: Getting detailed information

You can find detailed information about the fibre channel adapters in the location /sys/class/fc_host/

# ll /sys/class/fc_host/
drwxr-xr-x 3 root root 0 Feb  5 11:28 host3
drwxr-xr-x 3 root root 0 Feb  5 11:28 host4

The directories host3 and host4 in the example above contains information specific to each adapter like node name (WWN), port name (WWN), type, speed,state etc.,
An easier way to get this information is to use the systool command.

# systool -c fc_host
Class = "fc_host"
  Class Device = "host3"
    Device = "host3"
  Class Device = "host4"
    Device = "host4"

The -v option gives you detailed output

# systool -c fc_host -v host3
Class = "fc_host"

 Class Device = "host3"
 Class Device path = "/sys/class/fc_host/host3"
   fabric_name         = "0x50014380272531e9"
   issue_lip           = <store method only>
   node_name           = "0x50014380281412e9"
   port_id             = "0x0000e8"
   port_name           = "0x50014380281412e8"
   port_state          = "Online"
   port_type           = "LPort (private loop)"
   speed               = "8 Gbit"
   supported_classes   = "Class 3"
   supported_speeds    = "1 Gbit, 2 Gbit, 4 Gbit, 8 Gbit"
   symbolic_name       = "HPAK344A FW:v5.06.03 DVR:v8.03.07.09.05.08-k"
   system_hostname     = ""
   tgtid_bind_type     = "wwpn (World Wide Port Name)"
   uevent              = <store method only>

   Device = "host3"
   Device path = "/sys/devices/pci0000:00/0000:00:01.0/0000:07:00.0/host3"
     edc               = <store method only>
     fw_dump           =
     nvram             = "ISP "
     optrom_ctl        = <store method only>
     optrom            =
     reset             = <store method only>
     sfp               = ""
     uevent            = <store method only>
     vpd               = "&" 

How to scan new FC LUNS and SCSI disks in Linux ?

1.First find out how many disks are visible in “fdisk -l” .

# fdisk -l 2>/dev/null | egrep '^Disk' | egrep -v 'dm-' | wc -l

2.Find out how many host bus adapter configured in the Linux box.you can use “systool -fc_host -v” to verify available FC in the system.

# ls /sys/class/fc_host
host0  host1

In this case,you need to scan host0 & host1 HBA.


3.If the system virtual memory is too low ,then do not proceed further.If you have enough free virtual memory,then you can proceed with below command to scan new LUNS.

# echo "1" > /sys/class/fc_host/host0/issue_lip
# echo "- - -" > /sys/class/scsi_host/host0/scan
# echo "1" > /sys/class/fc_host/host1/issue_lip
# echo "- - -" > /sys/class/scsi_host/host1/scan

Note: You need to monitor the “issue_lip” in /var/log/messages to determine when the scan will complete.This operation is an asynchronous operation.

4.Verify if the new LUN is visible or not by counting the available disks.

# fdisk -l 2>/dev/null | egrep '^Disk' | egrep -v 'dm-' | wc -l

If any new LUNS added ,then you can see more count is more then before scanning the LUNS.