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Diffstat (limited to '')
| -rw-r--r-- | Documentation/device-mapper/dm-flakey.rst (renamed from Documentation/device-mapper/dm-flakey.txt) | 45 |
1 files changed, 31 insertions, 14 deletions
diff --git a/Documentation/device-mapper/dm-flakey.txt b/Documentation/device-mapper/dm-flakey.rst index 9f0e247d0877..86138735879d 100644 --- a/Documentation/device-mapper/dm-flakey.txt +++ b/Documentation/device-mapper/dm-flakey.rst @@ -1,3 +1,4 @@ +========= dm-flakey ========= @@ -15,17 +16,26 @@ underlying devices. Table parameters ---------------- + +:: + <dev path> <offset> <up interval> <down interval> \ [<num_features> [<feature arguments>]] Mandatory parameters: - <dev path>: Full pathname to the underlying block-device, or a - "major:minor" device-number. - <offset>: Starting sector within the device. - <up interval>: Number of seconds device is available. - <down interval>: Number of seconds device returns errors. + + <dev path>: + Full pathname to the underlying block-device, or a + "major:minor" device-number. + <offset>: + Starting sector within the device. + <up interval>: + Number of seconds device is available. + <down interval>: + Number of seconds device returns errors. Optional feature parameters: + If no feature parameters are present, during the periods of unreliability, all I/O returns errors. @@ -41,17 +51,24 @@ Optional feature parameters: During <down interval>, replace <Nth_byte> of the data of each matching bio with <value>. - <Nth_byte>: The offset of the byte to replace. - Counting starts at 1, to replace the first byte. - <direction>: Either 'r' to corrupt reads or 'w' to corrupt writes. - 'w' is incompatible with drop_writes. - <value>: The value (from 0-255) to write. - <flags>: Perform the replacement only if bio->bi_opf has all the - selected flags set. + <Nth_byte>: + The offset of the byte to replace. + Counting starts at 1, to replace the first byte. + <direction>: + Either 'r' to corrupt reads or 'w' to corrupt writes. + 'w' is incompatible with drop_writes. + <value>: + The value (from 0-255) to write. + <flags>: + Perform the replacement only if bio->bi_opf has all the + selected flags set. Examples: + +Replaces the 32nd byte of READ bios with the value 1:: + corrupt_bio_byte 32 r 1 0 - - replaces the 32nd byte of READ bios with the value 1 + +Replaces the 224th byte of REQ_META (=32) bios with the value 0:: corrupt_bio_byte 224 w 0 32 - - replaces the 224th byte of REQ_META (=32) bios with the value 0 |