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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 ReferenceThe HCL OneDB™ Administrator's Reference includes comprehensive descriptions of HCL OneDB™ configuration parameters, the system-monitoring interface (SMI) tables in the sysmaster database, the syntax of database server utilities such as onmode and onstat, logical-log records, disk structures, event alarms, and unnumbered error messages.
Configuring and monitoring HCL OneDB™
Disk Structures and Storage
Dbspace Structure and Storage
Structure of a Regular Dbspace
Structure of a Mirror Chunk

Structure of a Mirror Chunk

Each mirror chunk must be the same size as its primary chunk. When a mirror chunk is created, the database server writes the contents of the primary chunk to the mirror chunk immediately.

The mirror chunk contains the same control structures as the primary chunk. Mirrors of blobspace, sbspace, or dbspace chunks contain the same physical contents as their primary counterpart after the database server brings them online.

Mirror-Chunk Structure illustrates the mirror-chunk structure as it appears after the chunk is created.

begin figure description - The paragraph that precedes this figure describes the content of the figure. - end figure description — Figure 1: Mirror-Chunk Structure

The mirror-chunk structure always shows no free space because all of its space is reserved for mirroring. For more information, see the chapter on what is mirroring in the HCL OneDB™ Administrator's Guide.

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