Replace a Controller Energy Storage Module (ESM)

If a failed energy storage module (ESM) is not replaced, you run the risk of losing the data that is temporarily stored in the flash memory. If the external power to the Controller is lost as well, the potential for data loss rises dramatically. In case of an ESM failure, the Controller should go into write-through (conservative) mode so there is no data loss. Nevertheless, a failed ESM must be replaced as soon as possible to avoid the risk of data loss and to restore system performance.

Prerequisites:

Before handling a component, touch a grounded surface to discharge any static electricity.
Attach an electrostatic discharge (ESD) wrist strap to your wrist, and stand on an ESD mat while replacing components.
Ensure that a replacement ESM or a filler panel available to replace the ESM that you will be removing.

Each Controller has one ESM for every NVDIMM. ESMs are located inside the Controller's ESM drive compartment. An Oracle Flash Storage System with a basic configuration contains two ESMs and two NVDIMMs. An Oracle FS System configured for performance contains four ESMs and four NVDIMMS. ESMs are customer replaceable units (CRUs). The following figure shows the location of the ESM modules.

Figure 1 ESM ESM

Legend

1 ESM 0

2 ESM1

3 ESM 2

4 ESM 3

Important! Do not mix ESM and NVDIMM types. ESM type must match the NVDIMM type. For example, an ESM labeled A (ESM-A) must be paired with an NVDIMM labeled A (NVDIMM-A); The NVDIMM type is printed on a small label near the end of the NVDIMM cable.

Note: To replace an ESM, you do not need to remove the Controller from the rack or even extend it along the Controller rails.

Note: Make a note of the ESM slot where the failed ESM was located so that the replacement ESM can be placed in the same slot to avoid the risk of mis-configuration. Alternatively, replace the ESMs only one at a time, so that there is only one empty ESM slot at any point in time.

Procedure Overview