thread/process.
.. option:: ignore_zone_limits=bool
+
If this option is used, fio will ignore the maximum number of open
zones limit of the zoned block device in use, thus allowing the
option :option:`max_open_zones` value to be larger than the device
**mmaphuge** to work, the system must have free huge pages allocated. This
can normally be checked and set by reading/writing
:file:`/proc/sys/vm/nr_hugepages` on a Linux system. Fio assumes a huge page
- is 4MiB in size. So to calculate the number of huge pages you need for a
- given job file, add up the I/O depth of all jobs (normally one unless
- :option:`iodepth` is used) and multiply by the maximum bs set. Then divide
- that number by the huge page size. You can see the size of the huge pages in
- :file:`/proc/meminfo`. If no huge pages are allocated by having a non-zero
- number in `nr_hugepages`, using **mmaphuge** or **shmhuge** will fail. Also
- see :option:`hugepage-size`.
+ is 2 or 4MiB in size depending on the platform. So to calculate the
+ number of huge pages you need for a given job file, add up the I/O
+ depth of all jobs (normally one unless :option:`iodepth` is used) and
+ multiply by the maximum bs set. Then divide that number by the huge
+ page size. You can see the size of the huge pages in
+ :file:`/proc/meminfo`. If no huge pages are allocated by having a
+ non-zero number in `nr_hugepages`, using **mmaphuge** or **shmhuge**
+ will fail. Also see :option:`hugepage-size`.
**mmaphuge** also needs to have hugetlbfs mounted and the file location
should point there. So if it's mounted in :file:`/huge`, you would use
.. option:: hugepage-size=int
- Defines the size of a huge page. Must at least be equal to the system
- setting, see :file:`/proc/meminfo`. Defaults to 4MiB. Should probably
- always be a multiple of megabytes, so using ``hugepage-size=Xm`` is the
- preferred way to set this to avoid setting a non-pow-2 bad value.
+ Defines the size of a huge page. Must at least be equal to the system
+ setting, see :file:`/proc/meminfo` and
+ :file:`/sys/kernel/mm/hugepages/`. Defaults to 2 or 4MiB depending on
+ the platform. Should probably always be a multiple of megabytes, so
+ using ``hugepage-size=Xm`` is the preferred way to set this to avoid
+ setting a non-pow-2 bad value.
.. option:: lockmem=int
for both direct and buffered IO.
This engine defines engine specific options.
+ **io_uring_cmd**
+ Fast Linux native asynchronous I/O for pass through commands.
+ This engine defines engine specific options.
+
**libaio**
Linux native asynchronous I/O. Note that Linux may only support
queued behavior with non-buffered I/O (set ``direct=1`` or
**exec**
Execute 3rd party tools. Could be used to perform monitoring during jobs runtime.
+ **xnvme**
+ I/O engine using the xNVMe C API, for NVMe devices. The xnvme engine provides
+ flexibility to access GNU/Linux Kernel NVMe driver via libaio, IOCTLs, io_uring,
+ the SPDK NVMe driver, or your own custom NVMe driver. The xnvme engine includes
+ engine specific options. (See https://xnvme.io).
+
I/O engine specific parameters
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
values for trim IOs are ignored. This option is mutually exclusive with
the :option:`cmdprio_percentage` option.
-.. option:: fixedbufs : [io_uring]
+.. option:: fixedbufs : [io_uring] [io_uring_cmd]
+
+ If fio is asked to do direct IO, then Linux will map pages for each
+ IO call, and release them when IO is done. If this option is set, the
+ pages are pre-mapped before IO is started. This eliminates the need to
+ map and release for each IO. This is more efficient, and reduces the
+ IO latency as well.
+
+.. option:: nonvectored : [io_uring] [io_uring_cmd]
+
+ With this option, fio will use non-vectored read/write commands, where
+ address must contain the address directly. Default is -1.
- If fio is asked to do direct IO, then Linux will map pages for each
- IO call, and release them when IO is done. If this option is set, the
- pages are pre-mapped before IO is started. This eliminates the need to
- map and release for each IO. This is more efficient, and reduces the
- IO latency as well.
+.. option:: force_async=int : [io_uring] [io_uring_cmd]
-.. option:: registerfiles : [io_uring]
+ Normal operation for io_uring is to try and issue an sqe as
+ non-blocking first, and if that fails, execute it in an async manner.
+ With this option set to N, then every N request fio will ask sqe to
+ be issued in an async manner. Default is 0.
+
+.. option:: registerfiles : [io_uring] [io_uring_cmd]
With this option, fio registers the set of files being used with the
kernel. This avoids the overhead of managing file counts in the kernel,
making the submission and completion part more lightweight. Required
for the below :option:`sqthread_poll` option.
-.. option:: sqthread_poll : [io_uring]
+.. option:: sqthread_poll : [io_uring] [io_uring_cmd] [xnvme]
Normally fio will submit IO by issuing a system call to notify the
kernel of available items in the SQ ring. If this option is set, the
This frees up cycles for fio, at the cost of using more CPU in the
system.
-.. option:: sqthread_poll_cpu : [io_uring]
+.. option:: sqthread_poll_cpu : [io_uring] [io_uring_cmd]
When :option:`sqthread_poll` is set, this option provides a way to
define which CPU should be used for the polling thread.
+.. option:: cmd_type=str : [io_uring_cmd]
+
+ Specifies the type of uring passthrough command to be used. Supported
+ value is nvme. Default is nvme.
+
.. option:: hipri
- [io_uring]
+ [io_uring] [io_uring_cmd] [xnvme]
If this option is set, fio will attempt to use polled IO completions.
Normal IO completions generate interrupts to signal the completion of
the full *type.id* string. If no type. prefix is given, fio will add
'client.' by default.
+.. option:: conf=str : [rados]
+
+ Specifies the configuration path of ceph cluster, so conf file does not
+ have to be /etc/ceph/ceph.conf.
+
.. option:: busy_poll=bool : [rbd,rados]
Poll store instead of waiting for completion. Usually this provides better
If set, stdout and stderr streams are redirected to files named from the job name. Default is true.
+.. option:: xnvme_async=str : [xnvme]
+
+ Select the xnvme async command interface. This can take these values.
+
+ **emu**
+ This is default and used to emulate asynchronous I/O.
+ **thrpool**
+ Use thread pool for Asynchronous I/O.
+ **io_uring**
+ Use Linux io_uring/liburing for Asynchronous I/O.
+ **libaio**
+ Use Linux aio for Asynchronous I/O.
+ **posix**
+ Use POSIX aio for Asynchronous I/O.
+ **nil**
+ Use nil-io; For introspective perf. evaluation
+
+.. option:: xnvme_sync=str : [xnvme]
+
+ Select the xnvme synchronous command interface. This can take these values.
+
+ **nvme**
+ This is default and uses Linux NVMe Driver ioctl() for synchronous I/O.
+ **psync**
+ Use pread()/write() for synchronous I/O.
+
+.. option:: xnvme_admin=str : [xnvme]
+
+ Select the xnvme admin command interface. This can take these values.
+
+ **nvme**
+ This is default and uses linux NVMe Driver ioctl() for admin commands.
+ **block**
+ Use Linux Block Layer ioctl() and sysfs for admin commands.
+ **file_as_ns**
+ Use file-stat to construct NVMe idfy responses.
+
+.. option:: xnvme_dev_nsid=int : [xnvme]
+
+ xnvme namespace identifier, for userspace NVMe driver.
+
+.. option:: xnvme_iovec=int : [xnvme]
+
+ If this option is set. xnvme will use vectored read/write commands.
+
I/O depth
~~~~~~~~~
projects / fio.git / blobdiff