OAKD is the storage management system for Oracle Database Appliance. It provides storage discovery, auto configuration of storage, and disk management.
It has three modes: non-cluster, upgrade, and foreground. OAKD starts in non-cluster when Oracle Grid Infrastructure stack is not yet installed. After installation of Oracle Grid Infrastructure, OAKD starts in cluster mode.
Use odaadmcli commands to query information from OAKD or provide information to OAKD. It has various modules such as server configuration, storage management, resource monitoring, cluster synchronization, and disk events monitoring. When the appliance is started, OAKD uses LSI and Fishwrap library to discover storage. Configuration servers read XML configuration files describing various properties of various OAKD resources. OAKD provides storage configuration information contained in asmappl.config to Oracle ASM through oaklib library. oaklib also has an HTTPS interface used by OAKD to make REST API call to the DCS agent. The resource management module monitors various hardware components at regular intervals. Cluster communication modules waits for cluster reconfiguration events to take appropriate actions. OAKD monitors LSI and UDEV events for disk operations such as insert or removal and completes the action in OAKD and Oracle ASM.
OAKD monitors for predictive failure information on disk. OAKD also reads /proc/diskstats periodically for disk performance matrix. OAKD monitor for Oracle ASM action events such as disk offline or online events. It also performs auto online operation for transient failures which can cause Oracle ASM to offline a disk. Other modules such as DCS and Oracle Enterprise Manager plugin for Oracle Database Appliance use the odaadmcli interface to query storage information.