Removing and replacing a memory module

You can remove and replace a faulty dual inline memory module (DIMM) from a control enclosure. You can also use this procedure to add DIMMs to increase the memory capacity of the node canister.

About this task

Notes:
  • Electrostatic discharge precaution symbol The memory modules are sensitive to electrostatic-discharge (ESD). Take precautions to avoid damage from static electricity. When you remove or replace this part, you must follow recommended procedures for handling ESD-sensitive devices.
  • A screwdriver is required to open the node canister cover.
  • The hardware (for example labels on the printed circuit board) identifies the processors as CPU0 and CPU1, but the Storage Virtualize error messages identify them as CPU1 and CPU2.
  • All DIMMs are 64 GB, and supported configurations can have 8, 16 or 24 installed DIMMs in specific slots.
As Figure 1 shows, each node canister contains:
  • Five fans across the top
  • Two processors, which are identified as CPU 1 and CPU 2
  • 24 DIMM slots numbered 1 through 24.
Figure 1. Location of CPUs and DIMM slots
Location of CPUs and DIMM slots

 1  CPU1 to the Storage Virtualize Software and CPU 0 to the hardware. 2  CPU 2 to the Storage Virtualize Software and CPU 1 to the hardware.

  • A CPU processor can have 4, 8 or 12 DIMMs installed.
  • On the system board, the DIMM slots are labeled according to their memory channel and slot. They are associated with the CPU nearest to their DIMM slots.
  • You do not have to replace all memory modules at the same time. However, when you install memory modules, be sure that you follow the configurations that are described in the following table:
    Table 1. Available memory configurations for a control enclosure
    Total Memory per Control Enclosure 512 GB 1024 GB 1536 GB Slot label
    Features ACGM ACGM + ACGN ACGM + ACGN + ACGP  
     
    CH1-DIMM0 Blank 64 GB 64 GB 1
    CH0-DIMM0 64 GB 64 GB 64 GB 2
    CH0-DIMM1 Blank Blank 64 GB 3
    CH3-DIMM0 Blank 64 GB 64 GB 4
    CH2-DIMM0 64 GB 64 GB 64 GB 5
    CH3-DIMM1 Blank Blank 64 GB 6
    CPU 1
    CH6-DIMM1 Blank Blank 64 GB 7
    CH6-DIMM0 64 GB 64 GB 64 GB 8
    CH7-DIMM0 Blank 64 GB 64 GB 9
    CH4-DIMM1 Blank Blank 64 GB 10
    CH4-DIMM0 64 GB 64 GB 64 GB 11
    CH5-DIMM0 Blank 64 GB 64 GB 12
     
    CH1-DIMM0 Blank 64 GB 64 GB 13
    CH0-DIMM0 64 GB 64 GB 64 GB 14
    CH0-DIMM1 Blank Blank 64 GB 15
    CH3-DIMM0 Blank 64 GB 64 GB 16
    CH2-DIMM0 64 GB 64 GB 64 GB 17
    CH3-DIMM1 Blank Blank 64 GB 18
    CPU 2
    CH6-DIMM1 Blank Blank 64 GB 19
    CH6-DIMM0 64 GB 64 GB 64 GB 20
    CH7-DIMM0 Blank 64 GB 64 GB 21
    CH4-DIMM1 Blank Blank 64 GB 22
    CH4-DIMM0 64 GB 64 GB 64 GB 23
    CH5-DIMM0 Blank 64 GB 64 GB 24
If a node error 510 is logged (error code 1022 in the system log), the sense data includes the following information, that you can use to determine which DIMMs need to be replaced.
  • Detected memory size in MB.
  • Expected memory size in MB.
  • A list with one entry per DIMM slot, show the size of the DIMM in GB for each slot.

Procedure

Identifying failed DIMMs

  1. If you are replacing failed DIMMs, use the service assistant or the System Event Log in the management GUI to obtain the sense data. This data shows the detected and expected memory sizes and the size of the DIMM in each slot.
  2. Identify the column in the memory configuration table that contains the expected configuration. To do so, match the expected memory size from the error sense data to the column that has the same node canister total memory.
  3. Compare the size of DIMM reported in each slot in the error data with the expected DIMM size for the slot index and node canister total memory size that is shown in the memory configuration table. For each mismatch, the DIMM must be replaced with the size of DIMM that is indicated in the table. See the Replaceable units topic for the correct FRU part number for each size of DIMM.

Removing the node canister

  1. Follow Procedure: Powering off a node canister to verify that the hosts do not lose access to data in volumes.
  2. Remove the node canister, as described in Removing and reseating a node canister, and place it on a flat, level surface.
  3. Remove the cover, as described in Removing and replacing the cover of a node canister.

Removing the DIMM

Important: Do not start service status on the node. Power off the node to replace a DIMM or run the rmnode command to add DIMMs.
If you are upgrading memory of a node canister as a part of an enclosure upgrade, you must remove that node from the system configuration before you start the following procedure. To do so, you can use the management GUI or the CLI.
  • To use the management GUI, right-click the node canister and select Remove.
  • To use the CLI, enter the following command, where object_id | object_name identifies the node canister that receives the additional memory:
    rmnodecanister object_id | object_name
If you are replacing a faulty DIMM with a new one from FRU stock, you do not need to remove the node canister from the system configuration.

  1. Remove the air baffle. For details, see Removing and replacing the air baffle of a node canister.
  2. Locate the appropriate DIMM slot.
    As Figure 2, Figure 3, Figure 4, and Figure 5 shows that the DIMM locations are identified on the system board.
    Figure 2. Identifying DIMM locations 1-6
    Example of DIMM locations printed on the system board
    Figure 3. Identifying DIMM locations 7-12
    Example of DIMM locations printed on the system board
    Figure 4. Identifying DIMM locations 13-18
    Example of DIMM locations printed on the system board
    Figure 5. Identifying DIMM locations 19-24
    Example of DIMM locations printed on the system board
  3. Press the locking tabs on the side of the DIMM to eject it.
  4. Lift the DIMM up and out of the slot.
  5. If you have other tasks to complete inside the control enclosure, do those tasks now.

Replacing or adding the DIMM

Important: If you are adding memory to a node canister, you must remove that node from the system configuration before you start the following procedure. To do so, you can use the management GUI or the CLI.
  • To use the management GUI, right-click the node canister and select Remove.
  • To use the CLI, enter the following command, where object_id | object_name identifies the node canister that receives the additional memory:
    rmnodecanister object_id | object_name

If you are replacing a faulty DIMM with a new one from FRU stock, you do not need to remove the node canister from the system configuration.

  1. Touch the static-protective package that contains the new DIMM to any unpainted metal surface on the node canister. Remove the DIMM from the package.
  2. Turn the DIMM so that the DIMM keys align correctly with the connector on the main board.
  3. Insert the DIMM into the connector by aligning the edges of the DIMM with the slots at the ends of the DIMM connector.
    Attention: If there is a gap between the DIMM and the retaining clips, the DIMM is not correctly inserted; open the retaining clips, remove the DIMM, and then reinsert it.
  4. Apply pressure on both ends of the DIMM simultaneously and firmly press the DIMM straight down into the connector. The retaining clips snap into the locked position when the DIMM is firmly seated in the connector.
  5. Repeat steps 12 through 15 until all the new or replacement DIMMs are installed.
  6. Replace the air baffle. For details, see Removing and replacing the air baffle of a node canister.
  7. Install the cover, as described in Removing and replacing the cover of a node canister.
  8. Reinsert the node canister, as described in Removing and reseating a node canister.
    If the canister does not begin to power-up, check that the canister is fully inserted into the enclosure.
  9. When the node is active again, go to the management GUI and look for any unfixed events that are related to the DIMMs.