output_buffer: only realloc once, and memset just what we need

[fio.git] / README

diff --git a/README b/README
index 09175448fd444557d1ade5e4ab810480b2c9c204..9d0863d3af4160888e860330e64e66a4610ecb4c 100644 (file)
--- a/README
+++ b/README
@@ -26,15 +26,16 @@ Snapshots can download from:
 
        http://brick.kernel.dk/snaps/
 
-There are also two official mirrors. Both of these are synced within
-an hour of commits landing at git.kernel.dk. So if the main repo is
-down for some reason, either one of those is safe to use:
+There are also two official mirrors. Both of these are automatically synced
+with the main repository, when changes are pushed. If the main repo is down
+for some reason, either one of these is safe to use as a backup:
 
        git://git.kernel.org/pub/scm/linux/kernel/git/axboe/fio.git
        https://git.kernel.org/pub/scm/linux/kernel/git/axboe/fio.git
 
 or
 
+       git://github.com/axboe/fio.git
        https://github.com/axboe/fio.git
 
 
@@ -172,12 +173,17 @@ $ fio
        --warnings-fatal        Fio parser warnings are fatal
        --max-jobs              Maximum number of threads/processes to support
        --server=args           Start backend server. See Client/Server section.
-       --client=host           Connect to specified backend.
+       --client=host           Connect to specified backend(s).
        --remote-config=file    Tell fio server to load this local file
        --idle-prof=option      Report cpu idleness on a system or percpu basis
                                (option=system,percpu) or run unit work
                                calibration only (option=calibrate).
        --inflate-log=log       Inflate and output compressed log
+       --trigger-file=file     Execute trigger cmd when file exists
+       --trigger-timeout=t     Execute trigger af this time
+       --trigger=cmd           Set this command as local trigger
+       --trigger-remote=cmd    Set this command as remote trigger
+       --aux-path=path         Use this path for fio state generated files
 
 
 Any parameters following the options will be assumed to be job files,
@@ -311,17 +317,43 @@ to load a local file as well. This is done by using --remote-config:
 
 fio --client=server --remote-config /path/to/file.fio
 
-Then the fio serer will open this local (to the server) job file instead
+Then fio will open this local (to the server) job file instead
 of being passed one from the client.
 
+If you have many servers (example: 100 VMs/containers), 
+you can input a pathname of a file containing host IPs/names as the parameter 
+value for the --client option.  For example, here is an example "host.list" 
+file containing 2 hostnames:
+
+host1.your.dns.domain
+host2.your.dns.domain
+
+The fio command would then be:
+
+fio --client=host.list <job file(s)>
+
+In this mode, you cannot input server-specific parameters or job files -- all
+servers receive the same job file.  
+
+In order to let fio --client runs use a shared filesystem 
+from multiple hosts, fio  --client now prepends the IP address of the 
+server to the filename.  For example, if fio is using directory /mnt/nfs/fio 
+and is writing filename fileio.tmp, with a --client hostfile containing 
+two hostnames h1 and h2 with IP addresses 192.168.10.120 and  192.168.10.121,
+then fio will create two files:
+
+       /mnt/nfs/fio/192.168.10.120.fileio.tmp
+       /mnt/nfs/fio/192.168.10.121.fileio.tmp
+
 
 Platforms
 ---------
 
 Fio works on (at least) Linux, Solaris, AIX, HP-UX, OSX, NetBSD, OpenBSD,
-Windows and FreeBSD.  Some features and/or options may only be available on
-some of the platforms, typically because those features only apply to that
-platform (like the solarisaio engine, or the splice engine on Linux).
+Windows, FreeBSD, and DragonFly. Some features and/or options may only be
+available on some of the platforms, typically because those features only
+apply to that platform (like the solarisaio engine, or the splice engine on
+Linux).
 
 Some features are not available on FreeBSD/Solaris even if they could be
 implemented, I'd be happy to take patches for that. An example of that is