Add support for limiting only rate in only one direction
So now you can say 'limit writes to 10MB/sec' and have reads go
full throttle, for instance.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/HOWTO b/HOWTO
index 494b3e6..8f73208 100644
--- a/HOWTO
+++ b/HOWTO
@@ -588,19 +588,29 @@
defaults to 1 which will make fio wait 'thinktime' usecs
after every block.
-rate=int Cap the bandwidth used by this job to this number of KiB/sec.
+rate=int Cap the bandwidth used by this job. The number is in bytes/sec,
+ the normal postfix rules apply. You can use rate=500k to limit
+ reads and writes to 500k each, or you can specify read and
+ writes separately. Using rate=1m,500k would limit reads to
+ 1MB/sec and writes to 500KB/sec. Capping only reads or
+ writes can be done with rate=,500k or rate=500k,. The former
+ will only limit writes (to 500KB/sec), the latter will only
+ limit reads.
ratemin=int Tell fio to do whatever it can to maintain at least this
bandwidth. Failing to meet this requirement, will cause
- the job to exit.
+ the job to exit. The same format as rate is used for
+ read vs write separation.
rate_iops=int Cap the bandwidth to this number of IOPS. Basically the same
as rate, just specified independently of bandwidth. If the
job is given a block size range instead of a fixed value,
- the smallest block size is used as the metric.
+ the smallest block size is used as the metric. The same format
+ as rate is used for read vs write seperation.
rate_iops_min=int If fio doesn't meet this rate of IO, it will cause
- the job to exit.
+ the job to exit. The same format as rate is used for read vs
+ write seperation.
ratecycle=int Average bandwidth for 'rate' and 'ratemin' over this number
of milliseconds.