can specify a number of files by separating the names with a
':' colon. So if you wanted a job to open /dev/sda and /dev/sdb
as the two working files, you would use
- filename=/dev/sda:/dev/sdb. On Windows, disk devices are accessed
- as \\.\PhysicalDrive0 for the first device, \\.\PhysicalDrive1
- for the second etc.
- Note: Windows and FreeBSD prevent write access to areas of the disk
- containing in-use data (e.g. filesystems).
- If the wanted filename does need to include a colon, then escape that
- with a '\' character.
- For instance, if the filename is "/dev/dsk/foo@3,0:c",
- then you would use filename="/dev/dsk/foo@3,0\:c".
- '-' is a reserved name, meaning stdin or stdout. Which of the
- two depends on the read/write direction set.
+ filename=/dev/sda:/dev/sdb. On Windows, disk devices are
+ accessed as \\.\PhysicalDrive0 for the first device,
+ \\.\PhysicalDrive1 for the second etc. Note: Windows and
+ FreeBSD prevent write access to areas of the disk containing
+ in-use data (e.g. filesystems).
+ If the wanted filename does need to include a colon, then
+ escape that with a '\' character. For instance, if the filename
+ is "/dev/dsk/foo@3,0:c", then you would use
+ filename="/dev/dsk/foo@3,0\:c". '-' is a reserved name, meaning
+ stdin or stdout. Which of the two depends on the read/write
+ direction set.
opendir=str Tell fio to recursively add any file it can find in this
directory and down the file system tree.
ten unit instead, for obvious reasons. Allow values are
1024 or 1000, with 1024 being the default.
+unified_rw_reporting=bool Fio normally reports statistics on a per
+ data direction basis, meaning that read, write, and trim are
+ accounted and reported separately. If this option is set,
+ the fio will sum the results and report them as "mixed"
+ instead.
+
randrepeat=bool For random IO workloads, seed the generator in a predictable
way so that results are repeatable across repetitions.
sync fsync() the file
datasync fdatasync() the file
trim trim the given file from the given 'offset' for 'length' bytes
+
+
+9.0 CPU idleness profiling
+
+In some cases, we want to understand CPU overhead in a test. For example,
+we test patches for the specific goodness of whether they reduce CPU usage.
+fio implements a balloon approach to create a thread per CPU that runs at
+idle priority, meaning that it only runs when nobody else needs the cpu.
+By measuring the amount of work completed by the thread, idleness of each
+CPU can be derived accordingly.
+
+An unit work is defined as touching a full page of unsigned characters. Mean
+and standard deviation of time to complete an unit work is reported in "unit
+work" section. Options can be chosen to report detailed percpu idleness or
+overall system idleness by aggregating percpu stats.