DAOS error numbering starts at 1000. The most common errors are documented in the table below.
|DER_NOSPACE||1007||No space left on storage target|
|DER_NOSYS||1010||Function not implemented|
|DER_IO||2001||Generic I/O error|
|DER_ENOENT||2003||Entry not found|
|DER_KEY2BIG||2012||Key is too large|
|DER_IO_INVAL||2014||IO buffers can't match object extents|
When an operation fails, DAOS returns a negative DER error. For a full list of errors, please check https://github.com/daos-stack/cart/blob/master/src/include/gurt/errno.h (DER_ERR_GURT_BASE is equal to 1000 and DER_ERR_DAOS_BASE is equal to 2000).
The function d_errstr() is provided in the API to convert an error number to an error message.
On the server side, there are three log files created as part of normal server operations:
|Component||Config Parameter||Example Config Value|
Control Plane Log
The default log level for the control plane is INFO. The following
levels may be set using the
control_log_mask config parameter:
Data Plane Log
Data Plane (
daos_io_server) logging is configured on a per-instance
basis. In other words, each section under the
servers: section must
have its own logging configuration. The
log_file config parameter
is converted to a D_LOG_FILE environment variable value. For more
detail, please see the Debugging System
section of this document.
Privileged Helper Log
By default, the privileged helper only emits ERROR-level logging which
is captured by the control plane and included in that log. If the
helper_log_file parameter is set in the server config, then
DEBUG-level logging will be sent to the specified file.
DAOS uses the debug system defined in CaRT but more specifically the GURT library. Log files for both client and server are written to "/tmp/daos.log" unless otherwise set by D_LOG_FILE.
The debug logging system includes a series of subsystems or facilities which define groups for related log messages (defined per source file). There are common facilities which are defined in GURT, as well as other facilities that can be defined on a per-project basis (such as those for CaRT and DAOS). DD_SUBSYS can be used to set which subsystems to enable logging. By default all subsystems are enabled ("DD_SUBSYS=all").
DAOS Facilities: common, tree, vos, client, server, rdb, pool, container, object, placement, rebuild, tier, mgmt, bio, tests
Common Facilities (GURT): MISC, MEM
CaRT Facilities: RPC, BULK, CORPC, GRP, LM, HG, ST, IV
All macros that output logs have a priority level, shown in descending order below.
D_FATAL(fmt, ...) FATAL
D_CRIT(fmt, ...) CRIT
D_ERROR(fmt, ...) ERR
D_WARN(fmt, ...) WARN
D_NOTE(fmt, ...) NOTE
D_INFO(fmt, ...) INFO
D_DEBUG(mask, fmt, ...) DEBUG
The priority level that outputs to stderr is set with DD_STDERR. By default in DAOS (specific to the project), this is set to CRIT ("DD_STDERR=CRIT") meaning that all CRIT and more severe log messages will dump to stderr. However, this is separate from the priority of logging to "/tmp/daos.log". The priority level of logging can be set with D_LOG_MASK, which by default is set to INFO ("D_LOG_MASK=INFO"), which will result in all messages excluding DEBUG messages being logged. D_LOG_MASK can also be used to specify the level of logging on a per-subsystem basis as well ("D_LOG_MASK=DEBUG,MEM=ERR").
DEBUG messages account for a majority of the log messages, and finer-granularity might be desired. Mask bits are set as the first argument passed in D_DEBUG(mask, ...). To accomplish this, DD_MASK can be set to enable different debug streams. Similar to facilities, there are common debug streams defined in GURT, as well as other streams that can be defined on a per-project basis (CaRT and DAOS). All debug streams are enabled by default ("DD_MASK=all").
DAOS Debug Masks:
md = metadata operations
pl = placement operations
mgmt = pool management
epc = epoch system
df = durable format
rebuild = rebuild process
daos_default = (group mask) io, md, pl, and rebuild operations
Common Debug Masks (GURT):
any = generic messages, no classification
trace = function trace, tree/hash/lru operations
mem = memory operations
net = network operations
io = object I/Otest = test programs
Common Use Cases
Generic setup for all messages (default settings)
$ D_LOG_MASK=DEBUG $ DD_SUBSYS=all $ DD_MASK=all
Disable all logs for performance tuning
$ D_LOG_MASK=ERR -> will only log error messages from all facilities $ D_LOG_MASK=FATAL -> will only log system fatal messages
Disable a noisy debug logging subsystem
$ D_LOG_MASK=DEBUG,MEM=ERR -> disables MEM facility by restricting all logs from that facility to ERROR or higher priority only
Enable a subset of facilities of interest
$ DD_SUBSYS=rpc,tests $ D_LOG_MASK=DEBUG -> required to see logs for RPC and TESTS less severe than INFO (the majority of log messages)
Fine-tune the debug messages by setting a debug mask
$ D_LOG_MASK=DEBUG $ DD_MASK=mgmt -> only logs DEBUG messages related to pool management
Refer to the DAOS Environment Variables document for more information about the debug system environment.
Common DAOS Problems
This section to be updated in a future revision.
Bugs should be reported through our issue tracker^1 with a test case to reproduce the issue (when applicable) and debug logs.
After creating a ticket, logs should be gathered from the locations described in the Log Files section of this document and attached to the ticket.
To avoid problems with attaching large files, please attach the logs in a compressed container format, such as .zip or .tar.bz2.