Merge branch 'master' into gfio

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 73e82653f5e1c8315a2987a1c96e4458162a4507..b0d0a1fc6ca7831e30f603d3614398764ca7a61a 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -320,7 +320,7 @@ rw=str              Type of io pattern. Accepted values are:
                one by appending a ':<nr>' to the end of the string given.
                For a random read, it would look like 'rw=randread:8' for
                passing in an offset modifier with a value of 8. If the
-               postfix is used with a sequential IO pattern, then the value
+               suffix is used with a sequential IO pattern, then the value
                specified will be added to the generated offset for each IO.
                For instance, using rw=write:4k will skip 4k for every
                write. It turns sequential IO into sequential IO with holes.
@@ -602,6 +602,16 @@ ioengine=str       Defines how the job issues io to the file. The following
                                channel semantics (Send/Recv) for the
                                InfiniBand, RoCE and iWARP protocols.
 
+                       falloc   IO engine that does regular fallocate to
+                                simulate data transfer as fio ioengine.
+                                DDIR_READ  does fallocate(,mode = keep_size,)
+                                DDIR_WRITE does fallocate(,mode = 0)
+                                DDIR_TRIM  does fallocate(,mode = punch_hole)
+
+                       e4defrag IO engine that does regular EXT4_IOC_MOVE_EXT
+                                ioctls to simulate defragment activity in
+                                request to DDIR_WRITE event
+
                        external Prefix to specify loading an external
                                IO engine object file. Append the engine
                                filename, eg ioengine=external:/tmp/foo.o
@@ -893,6 +903,11 @@ create_fsync=bool  fsync the data file after creation. This is the
 create_on_open=bool    Don't pre-setup the files for IO, just create open()
                        when it's time to do IO to that file.
 
+create_only=bool       If true, fio will only run the setup phase of the job.
+                       If files need to be laid out or updated on disk, only
+                       that will be done. The actual job contents are not
+                       executed.
+
 pre_read=bool  If this is given, files will be pre-read into memory before
                starting the given IO operation. This will also clear
                the 'invalidate' flag, since it is pointless to pre-read
@@ -1107,8 +1122,8 @@ write_bw_log=str If given, write a bandwidth log of the jobs in this job
                file. Can be used to store data of the bandwidth of the
                jobs in their lifetime. The included fio_generate_plots
                script uses gnuplot to turn these text files into nice
-               graphs. See write_log_log for behaviour of given
-               filename. For this option, the postfix is _bw.log.
+               graphs. See write_lat_log for behaviour of given
+               filename. For this option, the suffix is _bw.log.
 
 write_lat_log=str Same as write_bw_log, except that this option stores io
                submission, completion, and total latencies instead. If no
@@ -1150,12 +1165,6 @@ exec_postrun=str After the job completes, issue the command specified
 ioscheduler=str        Attempt to switch the device hosting the file to the specified
                io scheduler before running.
 
-cpuload=int    If the job is a CPU cycle eater, attempt to use the specified
-               percentage of CPU cycles.
-
-cpuchunks=int  If the job is a CPU cycle eater, split the load into
-               cycles of the given time. In microseconds.
-
 disk_util=bool Generate disk utilization statistics, if the platform
                supports it. Defaults to on.
 
@@ -1233,6 +1242,19 @@ continue_on_error=str    Normally fio will exit the job on the first observed
 
                        1               Backward-compatible alias for 'all'.
 
+ignore_error=str Sometimes you want to ignore some errors during test
+                in that case you can specify error list for each error type.
+                ignore_error=READ_ERR_LIST,WRITE_ERR_LIST,VERIFY_ERR_LIST
+                errors for given error type is separated with ':'. Error
+                may be symbol ('ENOSPC', 'ENOMEM') or integer.
+                Example:
+                       ignore_error=EAGAIN,ENOSPC:122
+                This option will ignore EAGAIN from READ, and ENOSPC and 
+                122(EDQUOT) from WRITE. 
+
+error_dump=bool If set dump every error even if it is non fatal, true
+               by default. If disabled only fatal error will be dumped
+                                
 cgroup=str     Add job to this control group. If it doesn't exist, it will
                be created. The system must have a mounted cgroup blkio
                mount point for this to work. If your system doesn't have it
@@ -1286,6 +1308,11 @@ that defines them is selected.
                enabled when polling for a minimum of 0 events (eg when
                iodepth_batch_complete=0).
 
+[cpu] cpuload=int Attempt to use the specified percentage of CPU cycles.
+
+[cpu] cpuchunks=int Split the load into cycles of the given time. In
+               microseconds.
+
 [netsplice] hostname=str
 [net] hostname=str The host name or IP address to use for TCP or UDP based IO.
                If the job is a TCP listener or UDP reader, the hostname is not
@@ -1311,6 +1338,14 @@ that defines them is selected.
 [net] listen   For TCP network connections, tell fio to listen for incoming
                connections rather than initiating an outgoing connection. The
                hostname must be omitted if this option is used.
+[e4defrag] donorname=str
+               File will be used as a block donor(swap extents between files)
+[e4defrag] inplace=int
+               Configure donor file blocks allocation strategy         
+               0(default): Preallocate donor's file on init
+               1         : allocate space immidietly inside defragment event,
+                           and free right after event
+
 
 
 6.0 Interpreting the output
@@ -1448,6 +1483,9 @@ io_queue= Total time spent in the disk queue.
 util=          The disk utilization. A value of 100% means we kept the disk
                busy constantly, 50% would be a disk idling half of the time.
 
+It is also possible to get fio to dump the current output while it is
+running, without terminating the job. To do that, send fio the USR1 signal.
+
 
 7.0 Terse output
 ----------------