CDOT Tip #5

In 7-mode, configuration is largely stored in files: there are /etc/rc and /etc/exports, etc.  In CDOT, configuration is stored in optimized databases.  Here’s a quick primer on the main ones and what they do:

Replicated Database (RDB):

¡  Consists of four independent replication units:

−     Mgwd: management gateway

−     VLDB: volume location database

−     Vifmgr: VIF (LIF) manager

−     BCOM: Blocks Configuration Object Manager

¡  Uses data replication service for cluster configuration

−     Platform for single system image management

−     Synchronizes configuration data (e.g. volumes, LIFs)

¡  Stored in each node’s root volume

−     /mroot/etc/cluster_config/rdb/

¡  RDB processes run in user space on each node

¡  Do not manipulate directly  - only via CLI/System Manager/ZAPI

And some relevant admin tips:

¡  /mroot/etc/log or https://cluster-mgmt-lif/spi/node-name/etc/log/

−     Snapmirror, ems logs and others

¡  /mroot/etc/log/mlog or

−     RDB logs (bcomd, mgwd, vifmgr, vldb)

−     command-history.log

¡  /mroot/etc/crash or https://cluster-mgmt-lif/spi/node-name/etc/crash/

−     Core dump files               

¡  Event Viewer, cluster CLI event command or remote Web access are preferred methods to systemshell

¡  Access to any node’s mroot and logs, from any node

¡  Via systemshell (can ftp logs)

¡  Preferred: read-only Web access to log and core dump directories – available if node is online or taken over by its HA partner

¡  Setup KB 1013814: How to enable remote access to a node’s root volume in a cluster