Fix some shadow warnings for some gcc variants

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index e770b99de49879ce74afcdec7d6c84a553c25518..cdb7b013591b00078a05f0ba04b34ca8a0c4d182 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -253,7 +253,20 @@ machine.
 
 This section describes in details each parameter associated with a job.
 Some parameters take an option of a given type, such as an integer or
 
 This section describes in details each parameter associated with a job.
 Some parameters take an option of a given type, such as an integer or

-a string. The following types are used:
+a string. Anywhere a numeric value is required, an arithmetic expression
+may be used, provided it is surrounded by parentheses. Supported operators
+are:
+
+       addition (+)
+       subtraction (-)
+       multiplication (*)
+       division (/)
+       modulus (%)
+       exponentiation (^)
+
+For time values in expressions, units are microseconds by default. This is
+different than for time values not in expressions (not enclosed in
+parentheses). The following types are used:

 
 str    String. This is a sequence of alpha characters.
 time   Integer with possible time suffix. In seconds unless otherwise
 
 str    String. This is a sequence of alpha characters.
 time   Integer with possible time suffix. In seconds unless otherwise


@@ -379,7 +392,7 @@ rw=str              Type of io pattern. Accepted values are:
                For certain types of io the result may still be skewed a bit,
                since the speed may be different. It is possible to specify
                a number of IO's to do before getting a new offset, this is
                For certain types of io the result may still be skewed a bit,
                since the speed may be different. It is possible to specify
                a number of IO's to do before getting a new offset, this is

-               one by appending a ':<nr>' to the end of the string given.
+               done by appending a ':<nr>' to the end of the string given.

                For a random read, it would look like 'rw=randread:8' for
                passing in an offset modifier with a value of 8. If the
                suffix is used with a sequential IO pattern, then the value
                For a random read, it would look like 'rw=randread:8' for
                passing in an offset modifier with a value of 8. If the
                suffix is used with a sequential IO pattern, then the value


@@ -426,12 +439,6 @@ randseed=int       Seed the random number generators based on this seed value, to
                If not set, the random sequence depends on the randrepeat
                setting.
 
                If not set, the random sequence depends on the randrepeat
                setting.
 

-use_os_rand=bool Fio can either use the random generator supplied by the OS
-               to generator random offsets, or it can use it's own internal
-               generator (based on Tausworthe). Default is to use the
-               internal generator, which is often of better quality and
-               faster.
-

 fallocate=str  Whether pre-allocation is performed when laying down files.
                Accepted values are:
 
 fallocate=str  Whether pre-allocation is performed when laying down files.
                Accepted values are:
 


@@ -554,7 +561,7 @@ bssplit=str Sometimes you want even finer grained control of the
                while having 90% 4k writes and 10% 8k writes, you would
                specify:
 
                while having 90% 4k writes and 10% 8k writes, you would
                specify:
 

-               bssplit=2k/50:4k/50,4k/90,8k/10
+               bssplit=2k/50:4k/50,4k/90:8k/10

 
 blocksize_unaligned
 bs_unaligned   If this option is given, any byte size value within bsrange
 
 blocksize_unaligned
 bs_unaligned   If this option is given, any byte size value within bsrange


@@ -1309,6 +1316,21 @@ verify_backlog_batch=int Control how many blocks fio will verify
                if verify_backlog_batch is larger than verify_backlog, some
                blocks will be verified more than once.
 
                if verify_backlog_batch is larger than verify_backlog, some
                blocks will be verified more than once.
 

+verify_state_save=bool When a job exits during the write phase of a verify
+               workload, save its current state. This allows fio to replay
+               up until that point, if the verify state is loaded for the
+               verify read phase. The format of the filename is, roughly,
+               <type>-<jobname>-<jobindex>-verify.state. <type> is "local"
+               for a local run, "sock" for a client/server socket connection,
+               and "ip" (192.168.0.1, for instance) for a networked
+               client/server connection.
+
+verify_state_load=bool If a verify termination trigger was used, fio stores
+               the current write state of each thread. This can be used at
+               verification time so that fio knows how far it should verify.
+               Without this information, fio will run a full verification
+               pass, according to the settings in the job file used.
+

 stonewall
 wait_for_previous Wait for preceding jobs in the job file to exit, before
                starting this one. Can be used to insert serialization
 stonewall
 wait_for_previous Wait for preceding jobs in the job file to exit, before
                starting this one. Can be used to insert serialization


@@ -1627,7 +1649,9 @@ that defines them is selected.
                address.
 
 [netsplice] port=int
                address.
 
 [netsplice] port=int

-[net] port=int The TCP or UDP port to bind to or connect to.
+[net] port=int The TCP or UDP port to bind to or connect to. If this is used
+with numjobs to spawn multiple instances of the same job type, then this will
+be the starting port number since fio will use a range of ports.

 
 [netsplice] interface=str
 [net] interface=str  The IP address of the network interface used to send or
 
 [netsplice] interface=str
 [net] interface=str  The IP address of the network interface used to send or


@@ -1659,6 +1683,7 @@ that defines them is selected.
 [net] listen   For TCP network connections, tell fio to listen for incoming
                connections rather than initiating an outgoing connection. The
                hostname must be omitted if this option is used.
 [net] listen   For TCP network connections, tell fio to listen for incoming
                connections rather than initiating an outgoing connection. The
                hostname must be omitted if this option is used.

+

 [net] pingpong Normaly a network writer will just continue writing data, and
                a network reader will just consume packages. If pingpong=1
                is set, a writer will send its normal payload to the reader,
 [net] pingpong Normaly a network writer will just continue writing data, and
                a network reader will just consume packages. If pingpong=1
                is set, a writer will send its normal payload to the reader,


@@ -1671,6 +1696,10 @@ that defines them is selected.
                single reader when multiple readers are listening to the same
                address.
 
                single reader when multiple readers are listening to the same
                address.
 

+[net] window_size      Set the desired socket buffer size for the connection.
+
+[net] mss      Set the TCP maximum segment size (TCP_MAXSEG).
+

 [e4defrag] donorname=str
                File will be used as a block donor(swap extents between files)
 [e4defrag] inplace=int
 [e4defrag] donorname=str
                File will be used as a block donor(swap extents between files)
 [e4defrag] inplace=int