Fio 1.37

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 7a7d14ea0816080d794d25f4d899603e2eee57a8..886515b7aa754527070ee24ab785d66abb5b0b3e 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
@@ -563,6 +568,8 @@ fsync=int   If writing to a file, issue a sync of the dirty data
 
 fsyncdata=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()
 
 overwrite=bool If true, writes to a file will always overwrite existing
                data. If the file doesn't already exist, it will be
@@ -1004,22 +1011,22 @@ 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.
 
+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
 ---------------------------