forked from luck/tmp_suning_uos_patched
b26f5e3d71
Add 'drop_writes' option to drop writes silently while the device is 'down'. Reads are not touched. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
35 lines
1.2 KiB
Plaintext
35 lines
1.2 KiB
Plaintext
dm-flakey
|
|
=========
|
|
|
|
This target is the same as the linear target except that it exhibits
|
|
unreliable behaviour periodically. It's been found useful in simulating
|
|
failing devices for testing purposes.
|
|
|
|
Starting from the time the table is loaded, the device is available for
|
|
<up interval> seconds, then exhibits unreliable behaviour for <down
|
|
interval> seconds, and then this cycle repeats.
|
|
|
|
Also, consider using this in combination with the dm-delay target too,
|
|
which can delay reads and writes and/or send them to different
|
|
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.
|
|
|
|
Optional feature parameters:
|
|
If no feature parameters are present, during the periods of
|
|
unreliability, all I/O returns errors.
|
|
|
|
drop_writes:
|
|
All write I/O is silently ignored.
|
|
Read I/O is handled correctly.
|