+.RE
+.RE
+.TP
+.BI (libcufile)gpu_dev_ids\fR=\fPstr
+Specify the GPU IDs to use with CUDA. This is a colon-separated list of int.
+GPUs are assigned to workers roundrobin. Default is 0.
+.TP
+.BI (libcufile)cuda_io\fR=\fPstr
+Specify the type of I/O to use with CUDA. This option
+takes the following values:
+.RS
+.RS
+.TP
+.B cufile (default)
+Use libcufile and nvidia-fs. This option performs I/O directly
+between a GPUDirect Storage filesystem and GPU buffers,
+avoiding use of a bounce buffer. If \fBverify\fR is set,
+cudaMemcpy is used to copy verification data between RAM and GPU(s).
+Verification data is copied from RAM to GPU before a write
+and from GPU to RAM after a read.
+\fBdirect\fR must be 1.
+.TP
+.BI posix
+Use POSIX to perform I/O with a RAM buffer, and use
+cudaMemcpy to transfer data between RAM and the GPU(s).
+Data is copied from GPU to RAM before a write and copied
+from RAM to GPU after a read. \fBverify\fR does not affect
+the use of cudaMemcpy.
+.RE
+.RE
+.TP
+.BI (dfs)pool
+Specify the label or UUID of the DAOS pool to connect to.
+.TP
+.BI (dfs)cont
+Specify the label or UUID of the DAOS container to open.
+.TP
+.BI (dfs)chunk_size
+Specify a different chunk size (in bytes) for the dfs file.
+Use DAOS container's chunk size by default.
+.TP
+.BI (dfs)object_class
+Specify a different object class for the dfs file.
+Use DAOS container's object class by default.
+.TP
+.BI (nfs)nfs_url
+URL in libnfs format, eg nfs://<server|ipv4|ipv6>/path[?arg=val[&arg=val]*]
+Refer to the libnfs README for more details.
+.TP
+.BI (exec)program\fR=\fPstr
+Specify the program to execute.
+Note the program will receive a SIGTERM when the job is reaching the time limit.
+A SIGKILL is sent once the job is over. The delay between the two signals is defined by \fBgrace_time\fR option.
+.TP
+.BI (exec)arguments\fR=\fPstr
+Specify arguments to pass to program.
+Some special variables can be expanded to pass fio's job details to the program :
+.RS
+.RS
+.TP
+.B %r
+replaced by the duration of the job in seconds
+.TP
+.BI %n
+replaced by the name of the job
+.RE
+.RE
+.TP
+.BI (exec)grace_time\fR=\fPint
+Defines the time between the SIGTERM and SIGKILL signals. Default is 1 second.
+.TP
+.BI (exec)std_redirect\fR=\fPbool
+If set, stdout and stderr streams are redirected to files named from the job name. Default is true.
+.TP
+.BI (xnvme)xnvme_async\fR=\fPstr
+Select the xnvme async command interface. This can take these values.
+.RS
+.RS
+.TP
+.B emu
+This is default and use to emulate asynchronous I/O by using a single thread to
+create a queue pair on top of a synchronous I/O interface using the NVMe driver
+IOCTL.
+.TP
+.BI thrpool
+Emulate an asynchronous I/O interface with a pool of userspace threads on top
+of a synchronous I/O interface using the NVMe driver IOCTL. By default four
+threads are used.
+.TP
+.BI io_uring
+Linux native asynchronous I/O interface which supports both direct and buffered
+I/O.
+.TP
+.BI libaio
+Use Linux aio for Asynchronous I/O
+.TP
+.BI posix
+Use the posix asynchronous I/O interface to perform one or more I/O operations
+asynchronously.
+.TP
+.BI vfio
+Use the user-space VFIO-based backend, implemented using libvfn instead of
+SPDK.
+.TP
+.BI nil
+Do not transfer any data; just pretend to. This is mainly used for
+introspective performance evaluation.
+.RE
+.RE
+.TP
+.BI (xnvme)xnvme_sync\fR=\fPstr
+Select the xnvme synchronous command interface. This can take these values.
+.RS
+.RS
+.TP
+.B nvme
+This is default and uses Linux NVMe Driver ioctl() for synchronous I/O.
+.TP
+.BI psync
+This supports regular as well as vectored pread() and pwrite() commands.
+.TP
+.BI block
+This is the same as psync except that it also supports zone management
+commands using Linux block layer IOCTLs.
+.RE
+.RE
+.TP
+.BI (xnvme)xnvme_admin\fR=\fPstr
+Select the xnvme admin command interface. This can take these values.
+.RS
+.RS
+.TP
+.B nvme
+This is default and uses Linux NVMe Driver ioctl() for admin commands.
+.TP
+.BI block
+Use Linux Block Layer ioctl() and sysfs for admin commands.
+.RE
+.RE
+.TP
+.BI (xnvme)xnvme_dev_nsid\fR=\fPint
+xnvme namespace identifier for userspace NVMe driver SPDK or vfio.
+.TP
+.BI (xnvme)xnvme_dev_subnqn\fR=\fPstr
+Sets the subsystem NQN for fabrics. This is for xNVMe to utilize a fabrics
+target with multiple systems.
+.TP
+.BI (xnvme)xnvme_mem\fR=\fPstr
+Select the xnvme memory backend. This can take these values.
+.RS
+.RS
+.TP
+.B posix
+This is the default posix memory backend for linux NVMe driver.
+.TP
+.BI hugepage
+Use hugepages, instead of existing posix memory backend. The memory backend
+uses hugetlbfs. This require users to allocate hugepages, mount hugetlbfs and
+set an environment variable for XNVME_HUGETLB_PATH.
+.TP
+.BI spdk
+Uses SPDK's memory allocator.
+.TP
+.BI vfio
+Uses libvfn's memory allocator. This also specifies the use of libvfn backend
+instead of SPDK.
+.RE
+.RE
+.TP
+.BI (xnvme)xnvme_iovec
+If this option is set, xnvme will use vectored read/write commands.
+.TP
+.BI (libblkio)libblkio_driver \fR=\fPstr
+The libblkio driver to use. Different drivers access devices through different
+underlying interfaces. Available drivers depend on the libblkio version in use
+and are listed at \fIhttps://libblkio.gitlab.io/libblkio/blkio.html#drivers\fR
+.TP
+.BI (libblkio)libblkio_path \fR=\fPstr
+Sets the value of the driver-specific "path" property before connecting the
+libblkio instance, which identifies the target device or file on which to
+perform I/O. Its exact semantics are driver-dependent and not all drivers may
+support it; see \fIhttps://libblkio.gitlab.io/libblkio/blkio.html#drivers\fR
+.TP
+.BI (libblkio)libblkio_pre_connect_props \fR=\fPstr
+A colon-separated list of additional libblkio properties to be set after
+creating but before connecting the libblkio instance. Each property must have
+the format \fB<name>=<value>\fR. Colons can be escaped as \fB\\:\fR. These are
+set after the engine sets any other properties, so those can be overridden.
+Available properties depend on the libblkio version in use and are listed at
+\fIhttps://libblkio.gitlab.io/libblkio/blkio.html#properties\fR
+.TP
+.BI (libblkio)libblkio_num_entries \fR=\fPint
+Sets the value of the driver-specific "num-entries" property before starting the
+libblkio instance. Its exact semantics are driver-dependent and not all drivers
+may support it; see \fIhttps://libblkio.gitlab.io/libblkio/blkio.html#drivers\fR
+.TP
+.BI (libblkio)libblkio_queue_size \fR=\fPint
+Sets the value of the driver-specific "queue-size" property before starting the
+libblkio instance. Its exact semantics are driver-dependent and not all drivers
+may support it; see \fIhttps://libblkio.gitlab.io/libblkio/blkio.html#drivers\fR
+.TP
+.BI (libblkio)libblkio_pre_start_props \fR=\fPstr
+A colon-separated list of additional libblkio properties to be set after
+connecting but before starting the libblkio instance. Each property must have
+the format \fB<name>=<value>\fR. Colons can be escaped as \fB\\:\fR. These are
+set after the engine sets any other properties, so those can be overridden.
+Available properties depend on the libblkio version in use and are listed at
+\fIhttps://libblkio.gitlab.io/libblkio/blkio.html#properties\fR
+.TP
+.BI (libblkio)hipri
+Use poll queues. This is incompatible with \fBlibblkio_wait_mode=eventfd\fR and
+\fBlibblkio_force_enable_completion_eventfd\fR.
+.TP
+.BI (libblkio)libblkio_vectored
+Submit vectored read and write requests.
+.TP
+.BI (libblkio)libblkio_write_zeroes_on_trim
+Submit trims as "write zeroes" requests instead of discard requests.
+.TP
+.BI (libblkio)libblkio_wait_mode \fR=\fPstr
+How to wait for completions:
+.RS
+.RS
+.TP
+.B block \fR(default)
+Use a blocking call to \fBblkioq_do_io()\fR.
+.TP
+.B eventfd
+Use a blocking call to \fBread()\fR on the completion eventfd.
+.TP
+.B loop
+Use a busy loop with a non-blocking call to \fBblkioq_do_io()\fR.
+.RE
+.RE
+.TP
+.BI (libblkio)libblkio_force_enable_completion_eventfd
+Enable the queue's completion eventfd even when unused. This may impact
+performance. The default is to enable it only if
+\fBlibblkio_wait_mode=eventfd\fR.
+.TP
+.BI (windowsaio)no_completion_thread
+Avoid using a separate thread for completion polling.