IBM AIX Continuous Availability Features - IBM Redbooks

3.5 Live dump and component dump
Live dump and component dump capabilities are provided to allow failure data to be dumped
without taking down the entire system. Listed here are the most frequent uses of these
dumps:
► From the command line.
The system administrator issues the livedumpstart command to dump data related to a
failure.
► For recovery.
A subsystem wants to dump data pertaining to the failure before recovering. (This ability is
only available to the kernel and kernel extensions.)
The command dumpctrl can be used manage system dumps and live dumps. The command
also has several flags and options; refer to the dumpctrl man pages (man dumpctrl) for more
information.
The component dump allows the user, subsystem, or system administrator to request that
one or more components be dumped. When combined with the live dump functionality,
component dump allows components to be dumped, without bringing down the entire system.
When combined with the system dump functionality, component dump allows you to limit the
size of the system dump or disaster dump.
Note that the main users of these functions are IBM service personnel. Examples of the live
dump and component dump functions are provided here so that you can perform these
dumps if requested.
3.5.1 Dump-aware components
Depending on system type and configuration, many different types of dump-aware
components can exist. Later releases of AIX may add or delete components that exist on
current releases. The following list describes a few important components.
In our case, our test system had the following dump-aware components:
► Inter-process communication (ipc)
The ipc component currently has following subcomponents: semaphores data (sem);
shared memory segments data (shm); message queues data (msg).
► Virtual memory manager (vmm)
The vmm component currently has the following subcomponents: frame set data (frs);
memory pool data (memp); paging device data (pdt); system control data (pfhdata); page
size data (pst); interval data (vmint); kernel data (vmker); resource pool data (vmpool).
► Enhanced journaled file system (jfs2)
The jfs2 component currently has the following subcomponents: file system data; log data.
► Logical file system (lfs)
The lfs component currently has the following subcomponents: file system data; pile data;
General Purpose Allocator Interface (gpai) data (gpai is a collector of fifo, vfs, and vnode
data).
64 IBM AIX Continuous Availability Features