Fix windowsaio IO error handling and document device write access issue on Windows and FreeBSD.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/HOWTO b/HOWTO
index 6391b82..32e5d66 100644
--- a/HOWTO
+++ b/HOWTO
@@ -61,7 +61,7 @@
Num threads How many threads or processes should we spread
this workload over.
-
+
The above are the basic parameters defined for a workload, in addition
there's a multitude of parameters that modify other aspects of how this
job behaves.
@@ -274,11 +274,14 @@
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. 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
+ 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
@@ -1086,7 +1089,7 @@
less than verify_backlog then not all blocks will be verified,
if verify_backlog_batch is larger than verify_backlog, some
blocks will be verified more than once.
-
+
stonewall
wait_for_previous Wait for preceeding jobs in the job file to exit, before
starting this one. Can be used to insert serialization
@@ -1132,7 +1135,7 @@
for how to capture such logging data. For blktrace replay,
the file needs to be turned into a blkparse binary data
file first (blkparse <device> -o /dev/null -d file_for_fio.bin).
-
+
replay_no_stall=int When replaying I/O with read_iolog the default behavior
is to attempt to respect the time stamps within the log and
replay them with the appropriate delay between IOPS. By
@@ -1295,12 +1298,12 @@
may be symbol ('ENOSPC', 'ENOMEM') or integer.
Example:
ignore_error=EAGAIN,ENOSPC:122
- This option will ignore EAGAIN from READ, and ENOSPC and
- 122(EDQUOT) from WRITE.
+ This option will ignore EAGAIN from READ, and ENOSPC and
+ 122(EDQUOT) from WRITE.
error_dump=bool If set dump every error even if it is non fatal, true
by default. If disabled only fatal error will be dumped
-
+
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
@@ -1382,7 +1385,7 @@
[e4defrag] donorname=str
File will be used as a block donor(swap extents between files)
[e4defrag] inplace=int
- Configure donor file blocks allocation strategy
+ Configure donor file blocks allocation strategy
0(default): Preallocate donor's file on init
1 : allocate space immidietly inside defragment event,
and free right after event
@@ -1570,8 +1573,8 @@
Read merges, write merges,
Read ticks, write ticks,
Time spent in queue, disk utilization percentage
- Additional Info (dependant on continue_on_error, default off): total # errors, first error code
-
+ Additional Info (dependant on continue_on_error, default off): total # errors, first error code
+
Additional Info (dependant on description being set): Text description
Completion latency percentiles can be a grouping of up to 20 sets, so
@@ -1587,7 +1590,7 @@
8.0 Trace file format
---------------------
-There are two trace file format that you can encounter. The older (v1) format
+There are two trace file format that you can encounter. The older (v1) format
is unsupported since version 1.20-rc3 (March 2008). It will still be described
below in case that you get an old trace and want to understand it.
@@ -1624,7 +1627,7 @@
The filename is given as an absolute path. The action can be one of these:
add Add the given filename to the trace
-open Open the file with the given filename. The filename has to have
+open Open the file with the given filename. The filename has to have
been added with the add action before.
close Close the file with the given filename. The file has to have been
opened before.
@@ -1635,7 +1638,7 @@
filename action offset length
The filename is given as an absolute path, and has to have been added and opened
-before it can be used with this format. The offset and length are given in
+before it can be used with this format. The offset and length are given in
bytes. The action can be one of these:
wait Wait for 'offset' microseconds. Everything below 100 is discarded.