Memory rank sparing
Sparing enables a failing rank to be replaced by ranks installed in an unoccupied space. An unused spare rank on the channel can be used to copy the contents of a failing rank on that channel.
You can enable rank sparing memory in the Setup utility (see Starting the Setup utility).
The memory rank sparing mode requires an even number of DIMMs. If your server has an odd number of DIMMs installed, ensure that you disable the memory rank sparing mode from the Memory menu in Setup Utility. See Using the Setup utility.
Note
After disabling the memory rank sparing mode, if a message prompts that the memory configuration is not valid, restart the IMM2.1. Alternatively, you can turn off the server, disconnect it from and then reconnect it to ac power, and then turn on the server again.
The following diagram lists the DIMM connectors on each memory channel.
Figure 1. Connectors on each memory channel
Note
You can install DIMMs for the microprocessor 2 once the microprocessor 2 is installed. You do not need to wait until all of the DIMM connectors for microprocessor 1 are filled.
The following table shows the installation sequence for memory rank sparing mode:
| Number of DIMMs | Number of installed microprocessor | DIMM connector |
|---|---|---|
| First pair of DIMMs | 1 | 1, 2 |
| Second pair of DIMMs | 1 | 4, 5 |
| Third pair of DIMMs | 1 | 8, 9 |
| Fourth pair of DIMMs | 1 | 11, 12 |
| Fifth pair of DIMMs | 1 | 7, 10 |
| Sixth pair of DIMMs | 1 | 3, 6 |
| First pair of DIMMs | 2 | 1, 2 |
| Second pair of DIMMs | 2 | 13, 14 |
| Third pair of DIMMs | 2 | 4, 5 |
| Fourth pair of DIMMs | 2 | 16, 17 |
| Fifth pair of DIMMs | 2 | 8, 9 |
| Sixth pair of DIMMs | 2 | 20, 21 |
| Seventh pair of DIMMs | 2 | 11, 12 |
| Eighth pair of DIMMs | 2 | 23, 24 |
| Ninth pair of DIMMs | 2 | 7, 10 |
| Tenth pair of DIMMs | 2 | 19, 22 |
| Eleventh pair of DIMMs | 2 | 3, 6 |
| Twelfth pair of DIMMs | 2 | 15, 18 |
Note Rank Sparing is only supported when there is more than 1DPC or if a single QRDIMM is installed | ||
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