Restoring the path of an HDLM device started in disconnected status (when a restart is not required)

To restore the path of an HDLM device started in disconnected status (this procedure does not restart the host):

This subsection describes how to restore the path to an HDLM device that was in disconnected status (the cable was pulled out or broken) when the host first started. In this method, the host is not restarted. Note that this operation is applicable to the HDLM device managed by HDLM only. Also note that the target path of restoration can be a single, multiple, or all path to the HDLM device.

1. Execute the HDLM-configuration definition utility (dlmcfgmgr -v) or the view operation (dlnkmgr view -drv) of the HDLM command to check if the host was started while the path to the relevant HDLM device was in disconnected status.

   The following are examples of executing the command or utility:

   When executing the dlmcfgmgr utility with the -v option:

   # /sbin/dlmcfgmgr -v

   When executing the view operation with the -drv option:

   # /opt/DynamicLinkManager/bin/dlnkmgr view -drv

   If the SCSI device name mapped with the path to the relevant HDLM device is represented with a hyphen (-), in the execution result, this means that the path was in disconnected status.

   Perform this operation if necessary. If it is not necessary to check this, go to step 2.

2. Connect the cable.

   If the cable is broken, replace it.

3. Create the SCSI device for the path to be restored.

   Since you restore the path without restarting, the path for the SCSI device which was in disconnected status during bootup will not be created and you must execute the command for adding a device, shown in the following table, to manually create the SCSI device.

   Table. Add SCSI devices

   Purpose	Command
   Add a device (for FC-SAN environments)	When using any of the following OS and HBA driver combinations: - Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Oracle Linux 7, Oracle Linux 8#1,Oracle Linux 9, or Oracle Unbreakable Enterprise Kernel 8 and a QLogic HBA driver - SUSE LINUX Enterprise Server and a QLogic HBA driver - Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Oracle Linux 7, Oracle Linux 8, Oracle Linux 9, or Oracle Unbreakable Enterprise Kernel 8 and an Emulex HBA driver - SUSE LINUX Enterprise Server and an Emulex HBA driver Execute the following command: # echo "- - -" > /sys/class/scsi_host/hostn/scan# # If LUs for which I/O processing is being performed exist, execute the echo command for each device as follows: # echo "b c d" > /sys/class/scsi_host/hostn/scan Execute the following command to check whether the OS has recognized any devices: # cat /proc/scsi/scsi If the OS has not recognized any devices, stop the I/O processing, and then execute the following commands in the order shown: # echo "1" > /sys/class/fc_host/hostn/issue_lip # echo "- - -" > /sys/class/scsi_host/hostn/scan If you are using Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Oracle Linux 7, Oracle Linux 8, Oracle Linux 9, or SUSE LINUX Enterprise Server, the devices might be automatically recognized by the OS hot plug function. If the devices are recognized, the above procedure is not necessary.
   Adding a device (for IP-SAN environments)	For a device added to the target for which no session is established with the iSCSI initiator Execute the following command to make the OS recognize the target: # iscsiadm -m discovery -t sendtargets -p IP-address-of-the-target Then, log in to the target to establish a session. # iscsiadm -m node -T target-name -p IP-address-of-the-target:port-number-of-the-target --login For a device added to the target for which a session is established with the iSCSI initiator Execute the following command: # iscsiadm -m session -R

   Legend:

   a: Host ID (Port number of the host)

   b: Channel number (Bus number)

   c: Target ID

   d: Lun (LU number of the host)

   n: host port number

   driver-name: qlaxxxx (driver name in use)

   #1

   Oracle Linux 8 Update 1 does not support QLogic HBA drivers.

4. Wait until the automatic failback function starts, or execute the dlnkmgr command (dlnkmgr online -pathidAutoPATH_ID ).

   The relevant path is placed online.

   The following is an example of executing the HDLM command:

   # /opt/DynamicLinkManager/bin/dlnkmgr online -pathid AutoPATH_ID

5. Refer to /var/opt/DynamicLinkManager/log/dlmcfgmgr1.log or execute the dlmcfgmgr utility (dlmcfgmgr -v) to check if the path to the relevant HDLM device is restored.

   The following is an example of executing the dlmcfgmgr utility:

   # /sbin/dlmcfgmgr -v