summaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorJosef Bacik <josef@redhat.com>2011-03-24 13:54:24 +0000
committerAlasdair G Kergon <agk@redhat.com>2011-03-24 13:54:24 +0000
commit3407ef5262b55ca5d7139d2b555ef792fe531eec (patch)
treefb5e083851c636e515095bb3eb90325f4b175129 /Documentation
parent024d37e95ec4a7ccc256973ab2feab01f4fbdd2d (diff)
downloadlinux-3407ef5262b55ca5d7139d2b555ef792fe531eec.tar.gz
linux-3407ef5262b55ca5d7139d2b555ef792fe531eec.tar.bz2
linux-3407ef5262b55ca5d7139d2b555ef792fe531eec.zip
dm: add flakey target
This target is the same as the linear target except that it returns I/O errors periodically. It's been found useful in simulating failing devices for testing purposes. I needed a dm target to do some failure testing on btrfs's raid code, and Mike pointed me at this. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/device-mapper/dm-flakey.txt17
1 files changed, 17 insertions, 0 deletions
diff --git a/Documentation/device-mapper/dm-flakey.txt b/Documentation/device-mapper/dm-flakey.txt
new file mode 100644
index 000000000000..c8efdfd19a65
--- /dev/null
+++ b/Documentation/device-mapper/dm-flakey.txt
@@ -0,0 +1,17 @@
+dm-flakey
+=========
+
+This target is the same as the linear target except that it returns I/O
+errors 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 returns errors for <down interval> seconds,
+and then this cycle repeats.
+
+Parameters: <dev path> <offset> <up interval> <down interval>
+ <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.