Attempts to Remove a Node From Sun Fire 15K/12K Chassis Might Fail When Chassis Has Multiple Nodes in Same Partition (4856525)

When a Sun Fire 15K/12K chassis has two or more nodes configured into the same partition, attempts to remove the nodes from the partition might fail if that chassis is the only chassis with multiple nodes in that partition. This problem is caused by the need to create memory mapping aliases when multiple nodes from a chassis are configured into the same partition. This aliasing is done independently by every chassis that contributes multiple nodes to a common partition. When you remove all but one of a chassis's nodes from a partition, the aliasing created for that chassis will become invalid. Consider the following example:

• Begin with a partition consisting of three nodes:

  xc1-a, xc1-b, xc2-a

  where xc1 and xc2 are two Sun Fire 15K/12K systems.

• If you remove either xc1-a or xc1-b from the partition, the memory map aliasing for the xc1 system will become invalid.

However, if the partition includes two or more chassis's that contribute multiple nodes, the memory map aliasing created for the second chassis will compensate for the loss of aliasing in the first chassis. This compensation, which allows continued use of the partition, is shown in the following example:

• Begin with a partition consisting of four nodes:

  xc1-a, xc1-b, xc2-a, xc2-b

• If you remove either xc1-a or xc1-b from the partition, the memory map aliasing for the xc1 system will become invalid. However, the aliasing for chassis xc2 will remain valid. The partition can continue operation.

Workaround: The following procedure explains how to reduce to one the number of nodes a Sun Fire 15K/12K chassis contributes to a chassis, when the chassis is the only multiple-node chassis in that partition.

1. On the chassis with multiple nodes in the partition, remove all the chassis's nodes from the partition.

2. Add back the one node you want to include in the partition.

   For example, if you have a partition consisting of the nodes: xc1-a, xc1-b, and xc2-a, where xc1 and xc2 are two Sun Fire 15K/12K systems, and you want the partition to include only nodes xc1-a and xc2-a, proceed as follows:

3. Remove xc1-a and xc1-b from the partition.

4. Add xc1-a back into the partition.