X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=19304aefc87d92bc6fd17a3fd28f6768c79f8550;hp=9b3a6848e11c1a43867cd5da6a666ecff12df444;hb=ea3e51c36e09f9363c983de2ae123f983ee3f25c;hpb=892a6ffc5363ad7f1750df9f3ec98624016660cd

diff --git a/HOWTO b/HOWTO
index 9b3a6848..19304aef 100644
--- a/HOWTO
+++ b/HOWTO
@@ -324,6 +324,11 @@ kb_base=int	The base unit for a kilobyte. The defacto base is 2^10, 1024.
 randrepeat=bool	For random IO workloads, seed the generator in a predictable
 		way so that results are repeatable across repetitions.
 
+fallocate=bool	By default, fio will use fallocate() to advise the system
+		of the size of the file we are going to write. This can be
+		turned off with fallocate=0. May not be available on all
+		supported platforms.
+
 fadvise_hint=bool By default, fio will use fadvise() to advise the kernel
 		on what IO patterns it is likely to issue. Sometimes you
 		want to test specific IO patterns without telling the
@@ -561,8 +566,24 @@ fsync=int	If writing to a file, issue a sync of the dirty data
 		not sync the file. The exception is the sg io engine, which
 		synchronizes the disk cache anyway.
 
-fsyncdata=int	Like fsync= but uses fdatasync() to only sync data and not
+fdatasync=int	Like fsync= but uses fdatasync() to only sync data and not
 		metadata blocks.
+		In FreeBSD there is no fdatasync(), this falls back to
+		using fsync()
+
+sync_file_range=str:val	Use sync_file_range() for every 'val' number of
+		write operations. Fio will track range of writes that
+		have happened since the last sync_file_range() call. 'str'
+		can currently be one or more of:
+
+		wait_before	SYNC_FILE_RANGE_WAIT_BEFORE
+		write		SYNC_FILE_RANGE_WRITE
+		wait_after	SYNC_FILE_RANGE_WAIT_AFTER
+
+		So if you do sync_file_range=wait_before,write:8, fio would
+		use SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE for
+		every 8 writes. Also see the sync_file_range(2) man page.
+		This option is Linux specific.
 
 overwrite=bool	If true, writes to a file will always overwrite existing
 		data. If the file doesn't already exist, it will be
@@ -921,7 +942,7 @@ read_iolog=str	Open an iolog with the specified file name and replay the
 		to replay a workload captured by blktrace. See blktrace
 		for how to capture such logging data. For blktrace replay,
 		the file needs to be turned into a blkparse binary data
-		file first (blktrace <device> -d file_for_fio.bin).
+		file first (blkparse <device> -o /dev/null -d file_for_fio.bin).
 
 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
@@ -994,6 +1015,7 @@ gtod_cpu=int	Sometimes it's cheaper to dedicate a single thread of
 		for doing these time calls will be excluded from other
 		uses. Fio will manually clear it from the CPU mask of other
 		jobs.
+
 continue_on_error=bool	Normally fio will exit the job on the first observed
 		failure. If this option is set, fio will continue the job when
 		there is a 'non-fatal error' (EIO or EILSEQ) until the runtime
@@ -1003,6 +1025,27 @@ continue_on_error=bool	Normally fio will exit the job on the first observed
 		given in the stats is the first error that was hit during the
 		run.
 
+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
+		mounted, you can do so with:
+
+		# mount -t cgroup -o blkio none /cgroup
+
+cgroup_weight=int	Set the weight of the cgroup to this value. See
+		the documentation that comes with the kernel, allowed values
+		are in the range of 100..1000.
+
+cgroup_nodelete=bool Normally fio will delete the cgroups it has created after
+		the job completion. To override this behavior and to leave
+		cgroups around after the job completion, set cgroup_nodelete=1.
+		This can be useful if one wants to inspect various cgroup
+		files after job completion. Default: false
+
+uid=int		Instead of running as the invoking user, set the user ID to
+		this value before the thread/process does any work.
+
+gid=int		Set group ID, see uid.
 
 6.0 Interpreting the output
 ---------------------------