Asynchronous read and write using DDN's Infinite Memory Engine (IME).
This engine will try to stack as much IOs as possible by creating
requests for IME. FIO will then decide when to commit these requests.
+
**libiscsi**
Read and write iscsi lun with libiscsi.
+
**nbd**
Read and write a Network Block Device (NBD).
unless :option:`verify` is set or :option:`cuda_io` is `posix`.
:option:`iomem` must not be `cudamalloc`. This ioengine defines
engine specific options.
+
**dfs**
I/O engine supporting asynchronous read and write operations to the
DAOS File System (DFS) via libdfs.
Set the percentage of I/O that will be issued with the highest priority.
Default: 0. A single value applies to reads and writes. Comma-separated
values may be specified for reads and writes. For this option to be
- effective, NCQ priority must be supported and enabled, and `direct=1'
- option must be used. fio must also be run as the root user. Unlike
+ effective, NCQ priority must be supported and enabled, and the :option:`direct`
+ option must be set. fio must also be run as the root user. Unlike
slat/clat/lat stats, which can be tracked and reported independently, per
priority stats only track and report a single type of latency. By default,
completion latency (clat) will be reported, if :option:`lat_percentiles` is
meaning of priority may differ. See also the :option:`prio` option.
.. option:: cmdprio_bssplit=str[,str] : [io_uring] [libaio]
+
To get a finer control over I/O priority, this option allows
specifying the percentage of IOs that must have a priority set
depending on the block size of the IO. This option is useful only
map and release for each IO. This is more efficient, and reduces the
IO latency as well.
-.. option:: hipri : [io_uring]
-
- If this option is set, fio will attempt to use polled IO completions.
- Normal IO completions generate interrupts to signal the completion of
- IO, polled completions do not. Hence they are require active reaping
- by the application. The benefits are more efficient IO for high IOPS
- scenarios, and lower latencies for low queue depth IO.
-
.. option:: registerfiles : [io_uring]
With this option, fio registers the set of files being used with the
When :option:`sqthread_poll` is set, this option provides a way to
define which CPU should be used for the polling thread.
+.. option:: hipri
+
+ [io_uring]
+
+ If this option is set, fio will attempt to use polled IO completions.
+ Normal IO completions generate interrupts to signal the completion of
+ IO, polled completions do not. Hence they are require active reaping
+ by the application. The benefits are more efficient IO for high IOPS
+ scenarios, and lower latencies for low queue depth IO.
+
+ [pvsync2]
+
+ Set RWF_HIPRI on I/O, indicating to the kernel that it's of higher priority
+ than normal.
+
+ [sg]
+
+ If this option is set, fio will attempt to use polled IO completions.
+ This will have a similar effect as (io_uring)hipri. Only SCSI READ and
+ WRITE commands will have the SGV4_FLAG_HIPRI set (not UNMAP (trim) nor
+ VERIFY). Older versions of the Linux sg driver that do not support
+ hipri will simply ignore this flag and do normal IO. The Linux SCSI
+ Low Level Driver (LLD) that "owns" the device also needs to support
+ hipri (also known as iopoll and mq_poll). The MegaRAID driver is an
+ example of a SCSI LLD. Default: clear (0) which does normal
+ (interrupted based) IO.
+
.. option:: userspace_reap : [libaio]
Normally, with the libaio engine in use, fio will use the
reap events. The reaping mode is only enabled when polling for a minimum of
0 events (e.g. when :option:`iodepth_batch_complete` `=0`).
-.. option:: hipri : [pvsync2]
-
- Set RWF_HIPRI on I/O, indicating to the kernel that it's of higher priority
- than normal.
-
.. option:: hipri_percentage : [pvsync2]
When hipri is set this determines the probability of a pvsync2 I/O being high
Specifies the name of the RBD.
-.. option:: pool=str : [rbd,rados]
-
- Specifies the name of the Ceph pool containing RBD or RADOS data.
-
.. option:: clientname=str : [rbd,rados]
Specifies the username (without the 'client.' prefix) used to access the
Touching all objects affects ceph caches and likely impacts test results.
Enabled by default.
+.. option:: pool=str :
+
+ [rbd,rados]
+
+ Specifies the name of the Ceph pool containing RBD or RADOS data.
+
+ [dfs]
+
+ Specify the label or UUID of the DAOS pool to connect to.
+
+.. option:: cont=str : [dfs]
+
+ Specify the label or UUID of the DAOS container to open.
+
+.. option:: chunk_size=int
+
+ [dfs]
+
+ Specificy a different chunk size (in bytes) for the dfs file.
+ Use DAOS container's chunk size by default.
+
+ [libhdfs]
+
+ The size of the chunk to use for each file.
+
+.. option:: object_class=str : [dfs]
+
+ Specificy a different object class for the dfs file.
+ Use DAOS container's object class by default.
+
.. option:: skip_bad=bool : [mtd]
Skip operations against known bad blocks.
libhdfs will create chunk in this HDFS directory.
-.. option:: chunk_size : [libhdfs]
-
- The size of the chunk to use for each file.
-
.. option:: verb=str : [rdma]
The RDMA verb to use on this side of the RDMA ioengine connection. Valid
a valid stream identifier) fio will open a stream and then close it when done. Default
is 0.
-.. option:: hipri : [sg]
-
- If this option is set, fio will attempt to use polled IO completions.
- This will have a similar effect as (io_uring)hipri. Only SCSI READ and
- WRITE commands will have the SGV4_FLAG_HIPRI set (not UNMAP (trim) nor
- VERIFY). Older versions of the Linux sg driver that do not support
- hipri will simply ignore this flag and do normal IO. The Linux SCSI
- Low Level Driver (LLD) that "owns" the device also needs to support
- hipri (also known as iopoll and mq_poll). The MegaRAID driver is an
- example of a SCSI LLD. Default: clear (0) which does normal
- (interrupted based) IO.
-
.. option:: http_host=str : [http]
Hostname to connect to. For S3, this could be the bucket hostname.
GPU to RAM before a write and copied from RAM to GPU after a
read. :option:`verify` does not affect use of cudaMemcpy.
-.. option:: pool=str : [dfs]
-
- Specify the label or UUID of the DAOS pool to connect to.
-
-.. option:: cont=str : [dfs]
-
- Specify the label or UUID of the DAOS container to open.
-
-.. option:: chunk_size=int : [dfs]
-
- Specificy a different chunk size (in bytes) for the dfs file.
- Use DAOS container's chunk size by default.
-
-.. option:: object_class=str : [dfs]
-
- Specificy a different object class for the dfs file.
- Use DAOS container's object class by default.
-
.. option:: nfs_url=str : [nfs]
URL in libnfs format, eg nfs://<server|ipv4|ipv6>/path[?arg=val[&arg=val]*]
projects / fio.git / blobdiff