special purpose of also signaling the start of a new
job.
+wait_for=str Specifies the name of the already defined job to wait
+ for. Single waitee name only may be specified. If set, the job
+ won't be started until all workers of the waitee job are done.
+
+ Wait_for operates on the job name basis, so there are a few
+ limitations. First, the waitee must be defined prior to the
+ waiter job (meaning no forward references). Second, if a job
+ is being referenced as a waitee, it must have a unique name
+ (no duplicate waitees).
+
description=str Text description of the job. Doesn't do anything except
dump this text description when this job is run. It's
not parsed.
defines engine specific options.
libhdfs Read and write through Hadoop (HDFS).
- The 'filename' option is used to specify host,
- port of the hdfs name-node to connect. This
- engine interprets offsets a little
+ This engine interprets offsets a little
differently. In HDFS, files once created
cannot be modified. So random writes are not
possible. To imitate this, libhdfs engine
- expects bunch of small files to be created
- over HDFS, and engine will randomly pick a
- file out of those files based on the offset
- generated by fio backend. (see the example
- job file to create such files, use rw=write
- option). Please note, you might want to set
- necessary environment variables to work with
- hdfs/libhdfs properly.
+ creates bunch of small files, and engine will
+ pick a file out of those files based on the
+ offset enerated by fio backend. Each jobs uses
+ it's own connection to HDFS.
mtd Read, write and erase an MTD character device
(e.g., /dev/mtd0). Discards are treated as
to wait for each job to finish, sometimes that is not the
desired action.
+exitall_on_error When one job finishes in error, terminate the rest. The
+ default is to wait for each job to finish.
+
bwavgtime=int Average the calculated bandwidth over the given time. Value
is specified in milliseconds.
in the specified log file. This feature depends on the
availability of zlib.
-log_store_compressed=bool If set, and log_compression is also set,
- fio will store the log files in a compressed format. They
- can be decompressed with fio, using the --inflate-log
- command line parameter. The files will be stored with a
- .fz suffix.
+log_compression_cpus=str Define the set of CPUs that are allowed to
+ handle online log compression for the IO jobs. This can
+ provide better isolation between performance sensitive jobs,
+ and background compression work.
+
+log_store_compressed=bool If set, fio will store the log files in a
+ compressed format. They can be decompressed with fio, using
+ the --inflate-log command line parameter. The files will be
+ stored with a .fz suffix.
block_error_percentiles=bool If set, record errors in trim block-sized
units from writes and trims and output a histogram of
If the job is a TCP listener or UDP reader, the hostname is not
used and must be omitted unless it is a valid UDP multicast
address.
+[libhdfs] namenode=str The host name or IP address of a HDFS cluster namenode to contact.
[netsplice] port=int
[net] port=int The TCP or UDP port to bind to or connect to. If this is used
with numjobs to spawn multiple instances of the same job type, then this will
be the starting port number since fio will use a range of ports.
+[libhdfs] port=int the listening port of the HFDS cluster namenode.
[netsplice] interface=str
[net] interface=str The IP address of the network interface used to send or
[mtd] skip_bad=bool Skip operations against known bad blocks.
+[libhdfs] hdfsdirectory libhdfs will create chunk in this HDFS directory
+[libhdfs] chunck_size the size of the chunck to use for each file.
+
6.0 Interpreting the output
---------------------------