Add possibility to make sequential IO "holed"
For sequential IO, it is now possible to add a number of bytes to
be skipped for every block read or written. Using:
bs=8k
rw=read:8k
will first read 0k->8k, then 16k->24k, and so on. This skips 8k
for every 'bs' sized block read. Similar for writes, doing
bs=4k
rw=write:4k
will write 0k->4k, then 8k->12k, etc. End result being that every
other block is written, in a sequential fashion.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/fio.1 b/fio.1
index 40940f3..488896c 100644
--- a/fio.1
+++ b/fio.1
@@ -181,7 +181,10 @@
specify a number of IO's to do before getting a new offset, this is one by
appending a `:\fI<nr>\fR to the end of the string given. For a random read, it
would look like \fBrw=randread:8\fR for passing in an offset modifier with a
-value of 8. See the \fBrw_sequencer\fR option.
+value of 8. If the postfix is used with a sequential IO pattern, then the value
+specified will be added to the generated offset for each IO. For instance,
+using \fBrw=write:4k\fR will skip 4k for every write. It turns sequential IO
+into sequential IO with holes. See the \fBrw_sequencer\fR option.
.RE
.TP
.BI rw_sequencer \fR=\fPstr