$ sudo dmsetup create dust1 --table '0 33552384 dust /dev/vdb1 0 4096'
Check the status of the read behavior ("bypass" indicates that all I/O
-will be passed through to the underlying device)::
+will be passed through to the underlying device; "verbose" indicates that
+bad block additions, removals, and remaps will be verbosely logged)::
$ sudo dmsetup status dust1
- 0 33552384 dust 252:17 bypass
+ 0 33552384 dust 252:17 bypass verbose
$ sudo dd if=/dev/mapper/dust1 of=/dev/null bs=512 count=128 iflag=direct
128+0 records in
A message will print with the number of bad blocks currently
configured on the device::
- kernel: device-mapper: dust: countbadblocks: 895 badblock(s) found
+ countbadblocks: 895 badblock(s) found
Querying for specific bad blocks
--------------------------------
The following message will print if the block is in the list::
- device-mapper: dust: queryblock: block 72 found in badblocklist
+ dust_query_block: block 72 found in badblocklist
The following message will print if the block is not in the list::
- device-mapper: dust: queryblock: block 72 not found in badblocklist
+ dust_query_block: block 72 not found in badblocklist
The "queryblock" message command will work in both the "enabled"
and "disabled" modes, allowing the verification of whether a block
After clearing the bad block list, the following message will appear::
- kernel: device-mapper: dust: clearbadblocks: badblocks cleared
+ dust_clear_badblocks: badblocks cleared
If there were no bad blocks to clear, the following message will
appear::
- kernel: device-mapper: dust: clearbadblocks: no badblocks found
+ dust_clear_badblocks: no badblocks found
+
+Listing the bad block list
+--------------------------
+
+To list all bad blocks in the bad block list (using an example device
+with blocks 1 and 2 in the bad block list), run the following message
+command::
+
+ $ sudo dmsetup message dust1 0 listbadblocks
+ 1
+ 2
+
+If there are no bad blocks in the bad block list, the command will
+execute with no output::
+
+ $ sudo dmsetup message dust1 0 listbadblocks
Message commands list
---------------------
countbadblocks
clearbadblocks
+ listbadblocks
disable
enable
quiet