$ fio --name=random-writers --ioengine=libaio --iodepth=4 --rw=randwrite --bs=32k --direct=0 --size=64m --numjobs=4
+4.1 Environment variables
+-------------------------
+
fio also supports environment variable expansion in job files. Any
substring of the form "${VARNAME}" as part of an option value (in other
words, on the right of the `='), will be expanded to the value of the
fio ships with a few example job files, you can also look there for
inspiration.
+4.2 Reserved keywords
+---------------------
+
+Additionally, fio has a set of reserved keywords that will be replaced
+internally with the appropriate value. Those keywords are:
+
+$pagesize The architecture page size of the running system
+$mb_memory Megabytes of total memory in the system
+$ncpus Number of online available CPUs
+
+These can be used on the command line or in the job file, and will be
+automatically substituted with the current system values when the job
+is run. Simple math is also supported on these keywords, so you can
+perform actions like:
+
+size=8*$mb_memory
+
+and get that properly expanded to 8 times the size of memory in the
+machine.
+
5.0 Detailed list of parameters
-------------------------------
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. '-' is a reserved name, meaning
- stdin or stdout. Which of the two depends on the read/write
+ filename=/dev/sda:/dev/sdb. 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
sha256 Use sha256 as the checksum function.
+ sha1 Use optimized sha1 as the checksum function.
+
meta Write extra information about each io
(timestamp, block number etc.). The block
number is verified.
This option can be used for repeated burn-in tests of a
system to make sure that the written data is also
- correctly read back.
+ correctly read back. If the data direction given is
+ a read or random read, fio will assume that it should
+ verify a previously written file. If the data direction
+ includes any form of write, the verify will be of the
+ newly written data.
verifysort=bool If set, fio will sort written verify blocks when it deems
it faster to read them back in a sorted manner. This is
size of header_interval. blocksize should divide this
evenly.
-verify_pattern=int If set, fio will fill the io buffers with this
+verify_pattern=str If set, fio will fill the io buffers with this
pattern. Fio defaults to filling with totally random
bytes, but sometimes it's interesting to fill with a known
pattern for io verification purposes. Depending on the
width of the pattern, fio will fill 1/2/3/4 bytes of the
- buffer at the time. The verify_pattern cannot be larger than
- a 32-bit quantity.
+ buffer at the time(it can be either a decimal or a hex number).
+ The verify_pattern if larger than a 32-bit quantity has to
+ be a hex number that starts with either "0x" or "0X".
verify_fatal=bool Normally fio will keep checking the entire contents
before quitting on a block verification failure. If this
for doing these time calls will be excluded from other
uses. Fio will manually clear it from the CPU mask of other
jobs.
+
continue_on_error=bool Normally fio will exit the job on the first observed
failure. If this option is set, fio will continue the job when
there is a 'non-fatal error' (EIO or EILSEQ) until the runtime
given in the stats is the first error that was hit during the
run.
+cgroup=str Add job to this control group. If it doesn't exist, it will
+ be created. The system must have a mounted cgroup blkio
+ mount point for this to work. If your system doesn't have it
+ mounted, you can do so with:
+
+ # mount -t cgroup -o blkio none /cgroup
+
+cgroup_weight=int Set the weight of the cgroup to this value. See
+ the documentation that comes with the kernel, allowed values
+ are in the range of 100..1000.
+
+uid=int Instead of running as the invoking user, set the user ID to
+ this value before the thread/process does any work.
+
+gid=int Set group ID, see uid.
6.0 Interpreting the output
---------------------------
projects / fio.git / blobdiff