MultiPath configuration on RHEL5 and Clariion CX-300

emcfibre-channelmultipathqlogicrhel5

I have problem with discovering my FC-connected CX-300 storage. Frankly speaking I'm complete novice in FibreChannel, so step by step explanation would be appreciated. My configuration consist of two IBM HS20 blades with RHEL5.4 on board and 2x Qlogic ISP2422-based 4Gb Fibre Channel HBAs on each blade. As a FC switch there are two Brocades built in BladeCenter Chassis, and finally there is EMC Clariion CX-300.

CX300, and Brocade switches should be configured properly, because they were working fine with previous configuration, which main defference was RHEL3 instead RHEL5.4

Below there is my output from several usefull commands:

#lspci | grep Fibre
06:01.0 FibreChannle: Qlogic Corp. ISP2422-based 4Gb Fibre Channel to PCI-X HBA (rev 02)
06:01.1 FibreChannle: Qlogic Corp. ISP2422-based 4Gb Fibre Channel to PCI-X HBA (rev 02)


#lsmod | grep qla
qla2xxx             1084741 0
scsi_transport_fc     37577 1 qla2xxx
scsi_mod             141717 10 scsi_dh,qla2xxx,sg,scsi_transport_fc,usb_storage,libata,mptspi,mptscsih,scsi_transport_spi,sd_mod

#cat /proc/scsi/scsi
Attached Devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
  Vendor: LSILOGIC Model: 1030 IM    IM Rev: 1000
  Type:   Direct-Access                 ANSI SCSI revision: 02
Host: scsi0 Channel: 01 Id: 00 Lun: 00
  Vendor: IBM-ESXS Model: ST936701LC FN Rev: B418
  Type:   Direct-Access                 ANSI SCSI revision: 04
Host: scsi0 Channel: 01 Id: 00 Lun: 00
  Vendor: IBM-ESXS Model: ST936701LC FN Rev: B418
  Type:   Direct-Access                 ANSI SCSI revision: 04

I'd followed instructions from this site (editing /etc/multipath.conf), but i failed after multipath -ll – the output was empty.

Do you have any suggestions about discovering FC Connected LUNs in such configuration?

Best Answer

This configuration is not specific to EMC.

  1. Get your storage properly presented by your storage admin. You can assist the storage admin by providing the WWPN (like a fiber channel mac address) of each of your fiber channel NICs to him. You can find them by running the following command:

    for i in $(ls -1 /sys/class/scsi_host/); do cat /sys/class/scsi_host/$i/lpfc_symbolic_name; done;

    or

    for i in $(ls -1 /sys/class/scsi_host/); do cat /sys/class/scsi_host/$i/device/fc_host\:$i/port_name; done;

  2. Rescan your "scsi" bus (fiber channel is implemented as a scsi device in Linux) to detect the new block devices

    for i in $(ls -1 /sys/class/scsi_host/); do echo '- - -' > /sys/class/scsi_host/$i/scan

  3. Verify you can see the new devices by running multipath -ll

  4. Read, understand, and follow this documentation to complete your setup: http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/DM_Multipath/index.html

I refer you to the documentation for the last step because it's important that you understand how LVM might come into play. You might also want to take advantage of the fact that you can setup an alias for the block device so they are consistent in your environment.