Configure FalconStor (CircleOS 8) for Booting Single to Dual VIOS Setup

This process helps to identify and configure FalconStor to work on both Single and Dual VIOS. 

Note: These Steps should also be considered whenever a CircleOS Falconstor StoreSafe is being templated, copied to a new environment or copied to a another region.
 

Check configuration:

After powering on the FalconStor StorSafe CircleOS on a dual-vios system, perform the following checks:

1. Log in to your FalconStor StoreSafe System as root.

2. Run the following command to determine if multipath is enabled
   multipath -ll
   
   Sample Output:
   Configured Correctly:
   
   
   Not configured correctly:
   

   It is expected to see your root disk on the output, if not proceed to the next step.

3. Run the below command to identify if dual path is on the same disks.
   lsblk
   
   Sample output:
   Configured Correctly:
   
   
   Not configured correctly:
   
   
   It is expected that the above command output shows the OS disk as mpath* as shown in the correct sample screenshot, if not proceed to the next steps. 

Finding OS Disk WWID:

1. Examine the block device tree by running the below command and compare them with which tree they are from.
   lsblk
   Sample output:
   
   
   In this case, we see we only have 1 disk with root and it comes from two paths which is sda and sdb.
    

2. Using the information from the previous step, please run the below command string to get the WWID of the OS disk.

   read -p "Enter device name (e.g. sda, sdb): " DEV; WWID=$(/lib/udev/scsi_id --whitelisted --replace-whitespace --device=/dev/$DEV); echo "WWID of $DEV: $WWID"

   When you run this command string, specify the device name. and press enter. In this example its sda and note down its WWID number as we need that info for the next segment.
   Sample output:
   
   
    

Modifying multipath configuration:

1. Edit /etc/multipath.conf file using vi or nano editor and update the file with the following entries.
   vi /etc/multipath.conf

defaults {
   user_friendly_names yes
   polling_interval 10
   max_polling_interval 50
   reassign_maps yes
   failback immediate
   rr_min_io 2000
   no_path_retry 10
   checker_timeout 30
   find_multipaths smart
}

blacklist {
wwid ".*"
}

blacklist_exceptions {
wwid "<Your OS Disk WWID Number>"
}

Note: On this text block, modify the value "<Your OS Disk WWID Number>"  with your OS WWID disk that was noted from the segment "Finding OS Disk WWID" step 2.

Rebuilding initramfs

1. Rebuild the initramfs with the following command
   dracut -f -v

Rebooting the LPAR

1. Post rebuild the initramfs, reboot the LPAR using the below command
   shutdown -Fr now

Once the System/VM is powered on back, you can perform the "check configuration" steps. This time you should see correct sample outputs.

Your System/VM OS disk should now be configured for multipathing. This configuration is only required once, whenever your VM transitions from Single to Dual VIOS, is templated, copied to a new environment, or moved to another region. For this configuration, only the OS disk needs to be multipathed, as all other RAW disks are managed by the FalconStor StorSafe tool.

If you encounter any issues in this procedure please reach out to Kyndryl Cloud Uplift Support support.skytap.com for further assistance.