Fix blkparse typo

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 7a7d14ea0816080d794d25f4d899603e2eee57a8..19304aefc87d92bc6fd17a3fd28f6768c79f8550 100644 (file)
--- 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
@@ -1004,22 +1025,28 @@ 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_root=str        Root of the mounted blkio cgroup file systems. This is a Linux
-               specific IO controller. If your system doesn't have it mounted,
-               you can do so with:
+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
 
-               The cgroup_root defaults to /cgroup, if mounted elsewhere
-               please specify this option.
-
-cgroup=str     Add job to this control group. If it doesn't exist, it will
-               be created.
-
 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
 ---------------------------