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| -rw-r--r-- | HOWTO | 63 | ||||
| -rw-r--r-- | README | 7 |
2 files changed, 64 insertions, 6 deletions
@@ -8,7 +8,7 @@ Table of contents 5. Detailed list of parameters 6. Normal output 7. Terse output - +8. Trace file format 1.0 Overview and history ------------------------ @@ -1334,3 +1334,64 @@ Split up, the format is as follows: Additional Info (dependant on continue_on_error, default off): total # errors, first error code Additional Info (dependant on description being set): Text description + + +8.0 Trace file 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. + +In any case the trace is a simple text file with a single action per line. + + +8.1 Trace file format v1 +------------------------ +Each line represents a single io action in the following format: + +rw, offset, length + +where rw=0/1 for read/write, and the offset and length entries being in bytes. + +This format is not supported in Fio versions => 1.20-rc3. + + +8.2 Trace file format v2 +------------------------ +The second version of the trace file format was added in Fio version 1.17. +It allows to access more then one file per trace and has a bigger set of +possible file actions. + +The first line of the trace file has to be: + +fio version 2 iolog + +Following this can be lines in two different formats, which are described below. + +The file management format: + +filename action + +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 + been added with the add action before. +close Close the file with the given filename. The file has to have been + opened before. + + +The file io action format: + +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 +bytes. The action can be one of these: + +wait Wait for 'offset' microseconds. Everything below 100 is discarded. +read Read 'length' bytes beginning from 'offset' +write Write 'length' bytes beginning from 'offset' +sync fsync() the file +datasync fdatasync() the file +trim trim the given file from the given 'offset' for 'length' bytes @@ -289,11 +289,8 @@ The job file parameters are: can be used to gauge hard drive speed over the entire platter, without reading everything. Both x/y can include k/m/g suffix. - iolog=x Open and read io pattern from file 'x'. The file must - contain one io action per line in the following format: - rw, offset, length - where with rw=0/1 for read/write, and the offset - and length entries being in bytes. + read_iolog=x Open and read io pattern from file 'x'. The file format + is described in the HOWTO. write_iolog=x Write an iolog to file 'x' in the same format as iolog. The iolog options are exclusive, if both given the read iolog will be performed. Specify a separate file |