fio docs corrections

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 4e52e6509c18a6efb2350071d15b4899fb0be759..26a9b93b63037adb98a8d1de15c150cd31245d27 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -327,6 +327,14 @@ bs=int             The block size used for the io units. Defaults to 4k. Values
                can do so by passing an empty read size - bs=,8k will set
                8k for writes and leave the read default value.
 
+blockalign=int
+ba=int         At what boundary to align random IO offsets. Defaults to
+               the same as 'blocksize' the minimum blocksize given.
+               Minimum alignment is typically 512b for using direct IO,
+               though it usually depends on the hardware block size. This
+               option is mutually exclusive with using a random map for
+               files, so it will turn off that option.
+
 blocksize_range=irange
 bsrange=irange Instead of giving a single block size, specify a range
                and fio will mix the issued io block sizes. The issued
@@ -359,6 +367,15 @@ bssplit=str        Sometimes you want even finer grained control of the
                always add up to 100, if bssplit is given a range that adds
                up to more, it will error out.
 
+               bssplit also supports giving separate splits to reads and
+               writes. The format is identical to what bs= accepts. You
+               have to separate the read and write parts with a comma. So
+               if you want a workload that has 50% 2k reads and 50% 4k reads,
+               while having 90% 4k writes and 10% 8k writes, you would
+               specify:
+
+               bssplit=2k/50:4k/50,4k/90,8k/10
+
 blocksize_unaligned
 bs_unaligned   If this option is given, any byte size value within bsrange
                may be used as a block range. This typically wont work with
@@ -857,7 +874,7 @@ cpuload=int If the job is a CPU cycle eater, attempt to use the specified
                percentage of CPU cycles.
 
 cpuchunks=int  If the job is a CPU cycle eater, split the load into
-               cycles of the given time. In milliseconds.
+               cycles of the given time. In microseconds.
 
 disk_util=bool Generate disk utilization statistics, if the platform
                supports it. Defaults to on.
@@ -918,7 +935,7 @@ I           Thread initialized, waiting.
        M       Running, doing mixed sequential reads/writes.
        m       Running, doing mixed random reads/writes.
        F       Running, currently waiting for fsync()
-V              Running, doing verification of written data.
+       V       Running, doing verification of written data.
 E              Thread exited, not reaped by main thread yet.
 _              Thread reaped.