alt_diagpath - Alternate diagnostic data directory path configuration parameter
This parameter allows you to specify the fully qualified alternate path for Db2® diagnostic information that is used when the primary diagnostic data path, diagpath, is unavailable.
- Configuration type
- Database manager
- Applies to
- Database server with local and remote clients
- Database server with local clients
- Partitioned database server with local and remote clients
- Parameter type
- Configurable online
- Propagation class
- Default [range]
- Null [any valid path name, ,
'"pathname $h/trailing-dir"', ,
'"pathname $h$m"', or
- A directory path to use when the primary diagnostic data directory path is unavailable
- Resolves to
HOST_hostnameNote: Starting in Version 10, in Db2 pureScale® environments,
$hrefers to the member's home host.
- Resolves to
DIAG_numberis used regardless of whether it refers to a database partition, a CF, or a member.
- A single directory, or a directory and sub-directory to trail
$nThe following values are available:
The alternate diagnostic data directory can contain the same diagnostic data as the primary diagnostic data directory set with the diagpath parameter. When alt_diagpath is set and the primary diagnostic data directory becomes unavailable, diagnostic logging continues in the alternate diagnostic data directory path specified, then resumes in its original location when the primary diagnostic path becomes available again. If this parameter is null and the primary diagnostic data directory specified by the diagpath parameter is unavailable, no further diagnostic information is written until the primary diagnostic path becomes available again. For improved resilience, set the alternate diagnostic data directory to point to a different file system than the primary diagnostic data directory.
Starting in Db2
version 11.5.6 and while in a Db2
pureScale environment, the
alternate diagnostic data directory path used must contain at least one split token
$m) to ensure a private
db2diag log file for each member and CF.
- To avoid the operating system shell interpreting the $ sign on some Linux® and UNIX systems, a single quote must be placed outside of the double quote, as shown in the syntax.
- In the CLP interactive mode, or if the command is read and executed from an input file, the double quote is not required.
$nare case insensitive.
- The dynamic behavior for alt_diagpath does not extend to all processes.
- The db2sysc Db2 server process can detect dynamic changes, for example, when you issue the UPDATE DATABASE MANAGER CONFIGURATION command over an instance attachment.
- When Db2 client and application processes start, they use the alt_diagpath configuration parameter setting and do not detect any dynamic changes.
- On UNIX systems, if both diagpath and alt_diagpath are not available, the db2 diagnostic message is dumped to the syslog file.
- There is no default directory for alt_diagpath configuration parameter.
- The alt_diagpath and diagpath configuration parameters are exclusive to each other. They cannot be set to same directory path.
- If alt_diagpath (or diagpath) is unavailable that means diagnostic data dumping failed due to an error, such as: The directory was deleted, a disk error, disk is lost, network problems, file permission error, or disk is full.
- In Db2 pureScale environments, the CF diagnostic logs are placed into the alt_diagpath directory when the cf_diagpath directory is not available.