Implementation Guide › Installing CA Enterprise Log Manager › Installation Considerations for a System with SAN Drives › Install with Disabled SAN Drives › Set Up a Multipath Configuration for SAN Storage

Set Up a Multipath Configuration for SAN Storage

Setting up a multipath configuration is required for a CA Enterprise Log Manager system installed on a RAID system that is to use SAN storage. Physical disks on the SAN are partitioned into logical storage spaces named logical unit numbers (LUNs).

Set up a multipath configuration for SAN storage

1. Log on to the CA Enterprise Log Manager appliance and su to root.
2. (Optional) Do a directory listing of /dev/mapper to view the state of the configuration before setting up multipathing and logical volumes. Results resemble the following:

   drwxr-xr-x  2 root root     120 Jun 18 12:09 .
   drwxr-xr-x 11 root root    3540 Jun 18 16:09 ..
   crw-------  1 root root  10, 63 Jun 18 12:09 control
   brw-rw----  1 root disk 253,  0 Jun 18 16:09 VolGroup00-LogVol00
   brw-rw----  1 root disk 253,  2 Jun 18 12:09 VolGroup00-LogVol01
   brw-rw----  1 root disk 253,  1 Jun 18 16:09 VolGroup00-LogVol02
   

3. Open the .../etc/multipath.conf file for edit and proceed as follows:
   1. Add the following section under "device {" for each LUN provided by the SAN administrator:

      device {
      

      vendor                 "NETAPP"  
      product                "LUN"
      path_grouping_policy   multibus
      features               "1 queue_if_no_path"
      path_checker           readsector0 
      path_selector          "round-robin 0"
      failback               immediate
      no_path_retry          queue
           }
      

   2. Uncomment the 'blacklist' section for all devices. The blacklist section enables multipathing on default devices.

      blacklist {
      

      devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
      devnode "^hd[a-z]"
      devnode "^cciss!c[0-9]d[0-9]*"
      

      }
      

   3. Save and close the multipath.conf file.
4. Verify that Multipath is turned on and that the LUNs are listed by running the following:

   multipath -l
   

   Note: Paths display as ‘mpath0’ and ‘mpath1’. If the LUNs are not shown, reboot and run multipath again.

5. View the available drives.

   fdisk -l
   

6. List the available partitions and verify that 'mpath0' and 'mpath1' are listed.

   ls -la /dev/mapper
   

7. Map the first partition as follows:

   kpartx -a /dev/mapper/mpath0
   

8. Map the second partition as follows:

   kpartx -a /dev/mapper/mpath1