Hotplug of a multipath NVMe device (FW 1060 and later)

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Hot plug is the process of adding a component to the running operating system without interrupting the operations of the system. The Non-Volatile Memory Express (NVMe) devices contain unique Peripheral Component Interconnect (PCI) reset signals and logical power states. Only one logical device that is associated with a physical device needs to be powered on before you can power on the physical drive. However, both logical devices must be powered off before you can power off the physical drive.

HMC-based hotplug

Assume that a physical NVMe device U50EE.001.WZS000E-P3-C1 has two physical location codes, U50EE.001.WZS000E-P3-C1-R1 and U50EE.001.WZS000E-P3-C1-R2.

The following steps describe the method to hotplug a multipath NVMe device by using the Hardware Management Console (HMC):

  1. Dynamically remove the R1 and R2 paths from the logical partition (LPAR) on the HMC. Select the path devices, click Action > Remove Adapter, and then Save.

  2. Dynamically add R1 and R2 paths to the LPAR on the HMC. To select the path devices, click Add Adapter, select the paths, then click OK.

Linux-based hotplug

For example, a physical NVMe device U50EE.001.WZS000E-P3-C1 has two physical location codes, U50EE.001.WZS000E-P3-C1-R1 and U50EE.001.WZS000E-P3-C1-R2.

To hotplug a multipath NVMe device by using Linux® commands, complete the following steps:
  1. Enable the dynamic remove or add adapter in Linux.
  2. Remove the R1 path by using the following command:
    #  drmgr -r -c pci -s "U50EE.001.WZS000E-P3-C1-R1"
  3. Remove the R2 path by using the following command:
    #  drmgr -r -c pci -s "U50EE.001.WZS000E-P3-C1-R2"
  4. Add a NVMe device back into the LPAR by using the following command:
    # drmgr -a -c pci -s "U50EE.001.WZS000E-P3-C1-R1”
  5. Add the R2 path back into the LPAR by using the following command:
    # drmgr -a -c pci -s "U50EE.001.WZS000E-P3-C1-R2”