Move BITS_PER_LONG define to arch

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index dc70ab6693688e4078713abd0292bb8036915035..cdd6473b28f3574f7a8eca445715cb3d7156b93e 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -158,6 +158,9 @@ specify:
 
 $ 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
@@ -188,6 +191,20 @@ numjobs=4
 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.
+
 
 5.0 Detailed list of parameters
 -------------------------------
@@ -243,8 +260,11 @@ filename=str       Fio normally makes up a filename based on the job name,
                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
@@ -791,6 +811,8 @@ verify=str  If writing to a file, fio can verify the file contents
 
                        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.
@@ -801,7 +823,11 @@ verify=str If writing to a file, fio can verify the file contents
 
                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
@@ -820,13 +846,14 @@ verify_interval=int       Write the verification header at a finer granularity
                        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