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.
+ supported platforms. If using ZFS on Solaris this must be
+ set to 0 because ZFS doesn't support it.
fadvise_hint=bool By default, fio will use fadvise() to advise the kernel
on what IO patterns it is likely to issue. Sometimes you
job, can be overridden with a larger value for higher
concurrency. Note that increasing iodepth beyond 1 will not
affect synchronous ioengines (except for small degress when
- verify_async is in use). Even async engines my impose OS
+ verify_async is in use). Even async engines may impose OS
restrictions causing the desired depth not to be achieved.
This may happen on Linux when using libaio and not setting
direct=1, since buffered IO is not async on that OS. Keep an
the depth drain down to 4 before starting to fill it again.
direct=bool If value is true, use non-buffered io. This is usually
- O_DIRECT.
+ O_DIRECT. Note that ZFS on Solaris doesn't support direct io.
buffered=bool If value is true, use buffered io. This is the opposite
of the 'direct' option. Defaults to true.
io on zones of a file.
write_iolog=str Write the issued io patterns to the specified file. See
- read_iolog.
+ read_iolog. Specify a separate file for each job, otherwise
+ the iologs will be interspersed and the file may be corrupt.
read_iolog=str Open an iolog with the specified file name and replay the
io patterns it contains. This can be used to store a