X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=386fd12aa7b14b80405a4df2851b3c0f7e967fd0;hp=9e339bb8d0a608a2f83b141197bd1bbbb503804b;hb=9107a641e67f27003fa6cbe7b55b1ec6a0239197;hpb=24f67d1f97861e57c14baafde0ed2752a102668c diff --git a/HOWTO b/HOWTO index 9e339bb8..386fd12a 100644 --- a/HOWTO +++ b/HOWTO @@ -970,14 +970,15 @@ Target file/device Accepted values are: **none** - The :option:`zonerange`, :option:`zonesize` and - :option:`zoneskip` parameters are ignored. + The :option:`zonerange`, :option:`zonesize`, + :option `zonecapacity` and option:`zoneskip` + parameters are ignored. **strided** I/O happens in a single zone until :option:`zonesize` bytes have been transferred. After that number of bytes has been transferred processing of the next zone - starts. + starts. :option `zonecapacity` is ignored. **zbd** Zoned block device mode. I/O happens sequentially in each zone, even if random I/O @@ -1004,6 +1005,17 @@ Target file/device For :option:`zonemode` =zbd, this is the size of a single zone. The :option:`zonerange` parameter is ignored in this mode. + +.. option:: zonecapacity=int + + For :option:`zonemode` =zbd, this defines the capacity of a single zone, + which is the accessible area starting from the zone start address. + This parameter only applies when using :option:`zonemode` =zbd in + combination with regular block devices. If not specified it defaults to + the zone size. If the target device is a zoned block device, the zone + capacity is obtained from the device information and this option is + ignored. + .. option:: zoneskip=int For :option:`zonemode` =strided, the number of bytes to skip after @@ -1665,10 +1677,28 @@ Buffers and memory This will be ignored if :option:`pre_read` is also specified for the same job. -.. option:: sync=bool +.. option:: sync=str + + Whether, and what type, of synchronous I/O to use for writes. The allowed + values are: + + **none** + Do not use synchronous IO, the default. + + **0** + Same as **none**. + + **sync** + Use synchronous file IO. For the majority of I/O engines, + this means using O_SYNC. + + **1** + Same as **sync**. + + **dsync** + Use synchronous data IO. For the majority of I/O engines, + this means using O_DSYNC. - Use synchronous I/O for buffered writes. For the majority of I/O engines, - this means using O_SYNC. Default: false. .. option:: iomem=str, mem=str @@ -1889,14 +1919,6 @@ I/O engine single CPU at the desired rate. A job never finishes unless there is at least one non-cpuio job. - **guasi** - The GUASI I/O engine is the Generic Userspace Asynchronous Syscall - Interface approach to async I/O. See - - http://www.xmailserver.org/guasi-lib.html - - for more info on GUASI. - **rdma** The RDMA I/O engine supports both RDMA memory semantics (RDMA_WRITE/RDMA_READ) and channel semantics (Send/Recv) for the @@ -2470,7 +2492,8 @@ I/O depth can increase latencies. The benefit is that fio can manage submission rates independently of the device completion rates. This avoids skewed latency reporting if I/O gets backed up on the device side (the coordinated omission - problem). + problem). Note that this option cannot reliably be used with async IO + engines. I/O rate @@ -2613,6 +2636,9 @@ I/O replay character. See the :option:`filename` option for information on how to escape ':' characters within the file names. These files will be sequentially assigned to job clones created by :option:`numjobs`. + '-' is a reserved name, meaning read from stdin, notably if + :option:`filename` is set to '-' which means stdin as well, then + this flag can't be set to '-'. .. option:: read_iolog_chunked=bool @@ -2846,15 +2872,10 @@ Threads, processes and job synchronization ``flow=8`` and another job has ``flow=-1``, then there will be a roughly 1:8 ratio in how much one runs vs the other. -.. option:: flow_watermark=int - - The maximum value that the absolute value of the flow counter is allowed to - reach before the job must wait for a lower value of the counter. - .. option:: flow_sleep=int - The period of time, in microseconds, to wait after the flow watermark has - been exceeded before retrying operations. + The period of time, in microseconds, to wait after the flow counter + has exceeded its proportion before retrying operations. .. option:: stonewall, wait_for_previous @@ -4165,7 +4186,7 @@ Fio supports a variety of log file formats, for logging latencies, bandwidth, and IOPS. The logs share a common format, which looks like this: *time* (`msec`), *value*, *data direction*, *block size* (`bytes`), - *offset* (`bytes`) + *offset* (`bytes`), *command priority* *Time* for the log entry is always in milliseconds. The *value* logged depends on the type of log, it will be one of the following: @@ -4190,6 +4211,9 @@ The entry's *block size* is always in bytes. The *offset* is the position in byt from the start of the file for that particular I/O. The logging of the offset can be toggled with :option:`log_offset`. +*Command priority* is 0 for normal priority and 1 for high priority. This is controlled +by the ioengine specific :option:`cmdprio_percentage`. + Fio defaults to logging every individual I/O but when windowed logging is set through :option:`log_avg_msec`, either the average (by default) or the maximum (:option:`log_max_value` is set) *value* seen over the specified period of time