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AdministeringIn addition to administering the database server, you can tune performance, replicate data, and archive data.
System administrationThese topics contain concepts, procedures, and reference information for database and database server administrators to use for managing and tuning HCL OneDB™ database servers.
Administrator's GuideThe HCL OneDB™ Administrator's Guide provides the information required to administer HCL OneDB™.
Disk, memory, and process management
Shared memoryThese topics describe the content of database server shared memory, the factors that determine the sizes of shared-memory areas, and how data moves into and out of shared memory.
Processes that attach to shared memoryA number of processes attach to the database server shared memory.
How virtual processors attach to shared memoryThe database server virtual processors attach to shared memory during setup.
Define the shared-memory lower-boundary addressIf your operating system uses a parameter to define the lower boundary address for shared memory, and the parameter is set incorrectly, it can prevent the shared-memory segments from being attached contiguously.

Define the shared-memory lower-boundary address

If your operating system uses a parameter to define the lower boundary address for shared memory, and the parameter is set incorrectly, it can prevent the shared-memory segments from being attached contiguously.

The following figure illustrates the problem. If the lower-boundary address is less than the ending address of the previous segment plus the size of the current segment, the operating system attaches the current segment at a point beyond the end of the previous segment. This action creates a gap between the two segments. Because shared memory must be attached to a virtual processor so that it looks like contiguous memory, this gap creates problems. The database server receives errors when this situation occurs.

To correct the problem, check the operating-system kernel parameter that specifies the lower-boundary address or reconfigure the kernel to allow larger shared-memory segments.

The paragraphs that precede this figure describe the content of the figure. — Figure 1: Shared-memory lower-boundary address overview

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