Hi folks, I am currently implementing an incremental backup tool of dm-thin-provisioning volumes based on this post (https://www.redhat.com/archives/dm-devel/2012-May/msg00140.html). I clone the latest thin-provisioning-tools from github and use ubuntu 13.04 (linux 3.8.0-19) as host OS. However, as I try to perform some stress tests on my backup tool, I find a weird output of thin_dump which I cannot be sure if it is a bug or not. This output can be reproduced by the following steps: 1. create an origin logical volume lv1 with lvm2 2. write some data into lv1 3. take a snapshot on lv1 4. create another origin logical volume lv2 5. write some data into lv2 As you can see from the output of thin_dump listed below, the data mappings of lv2 (dev_id="3") is duplicated in both lv1 (dev_id="1") and its snapshot (dev_id="2"). Is this normal? Any help would be grateful Thanks Dennis The output of thin_dump is summarized as follow: <superblock uuid="" time="1" transaction="3" data_block_size="2048" nr_data_blocks="9216 metadata_snap="3"> <device dev_id="1" mapped_blocks="1753" transaction="0" creation_time="0" snap_time="1"> <single_mapping origin_block="0" data_block="1753" time="1"/> <range_mapping origin_begin="1" data_begin="72" length="31" time="0"/> <single_mapping origin_block="32" data_block="1" time="0"/> <range_mapping origin_begin="33" data_begin="103" length="2" time="0"/> <single_mapping origin_block="35" data_block="968" time="0"/> <range_mapping origin_begin="36" data_begin="1049" length="2" time="0"/> <single_mapping origin_block="38" data_block="1207" time="0"/> <range_mapping origin_begin="39" data_begin="1281" length="3" time="0"/> <range_mapping origin_begin="42" data_begin="1465" length="2" time="0"/> <single_mapping origin_block="128" data_block="2" time="0"/> <range_mapping origin_begin="129" data_begin="105" length="63" time="0"/> <range_mapping origin_begin="192" data_begin="867" length="21" time="0"/> <range_mapping origin_begin="213" data_begin="922" length="11" time="0"/> <range_mapping origin_begin="224" data_begin="168" length="12" time="0"/> <range_mapping origin_begin="236" data_begin="863" length="4" time="0"/> <range_mapping origin_begin="240" data_begin="180" length="144" time="0"/> <single_mapping origin_block="384" data_block="3" time="0"/> <range_mapping origin_begin="385" data_begin="933" length="7" time="0"/> <range_mapping origin_begin="392" data_begin="324" length="248" time="0"/> <single_mapping origin_block="640" data_block="4" time="0"/> <range_mapping origin_begin="641" data_begin="940" length="7" time="0"/> <range_mapping origin_begin="648" data_begin="572" length="243" time="0"/> <range_mapping origin_begin="891" data_begin="947" length="5" time="0"/> <single_mapping origin_block="896" data_block="5" time="0"/> <range_mapping origin_begin="897" data_begin="920" length="2" time="0"/> <range_mapping origin_begin="899" data_begin="952" length="5" time="0"/> <range_mapping origin_begin="904" data_begin="815" length="48" time="0"/> <range_mapping origin_begin="952" data_begin="888" length="32" time="0"/> continue ... <single_mapping origin_block="0" data_block="1754" time="1"/> <single_mapping origin_block="32" data_block="1755" time="1"/> <single_mapping origin_block="128" data_block="1756" time="1"/> <single_mapping origin_block="384" data_block="1757" time="1"/> <single_mapping origin_block="640" data_block="1758" time="1"/> <single_mapping origin_block="896" data_block="1759" time="1"/> <range_mapping origin_begin="1024" data_begin="1760" length="64" time="1"/> <single_mapping origin_block="1152" data_block="1824" time="1"/> <single_mapping origin_block="2047" data_block="1825" time="1"/> </device> <device dev_id="2" mapped_blocks="1753" transaction="1" creation_time="1" snap_time="1"> <single_mapping origin_block="0" data_block="0" time="0"/> <range_mapping origin_begin="1" data_begin="72" length="31" time="0"/> <single_mapping origin_block="32" data_block="1" time="0"/> <range_mapping origin_begin="33" data_begin="103" length="2" time="0"/> <single_mapping origin_block="35" data_block="968" time="0"/> <range_mapping origin_begin="36" data_begin="1049" length="2" time="0"/> <single_mapping origin_block="38" data_block="1207" time="0"/> <range_mapping origin_begin="39" data_begin="1281" length="3" time="0"/> <range_mapping origin_begin="42" data_begin="1465" length="2" time="0"/> <single_mapping origin_block="128" data_block="2" time="0"/> <range_mapping origin_begin="129" data_begin="105" length="63" time="0"/> <range_mapping origin_begin="192" data_begin="867" length="21" time="0"/> <range_mapping origin_begin="213" data_begin="922" length="11" time="0"/> continue ... <single_mapping origin_block="0" data_block="1754" time="1"/> <single_mapping origin_block="32" data_block="1755" time="1"/> <single_mapping origin_block="128" data_block="1756" time="1"/> <single_mapping origin_block="384" data_block="1757" time="1"/> <single_mapping origin_block="640" data_block="1758" time="1"/> <single_mapping origin_block="896" data_block="1759" time="1"/> <range_mapping origin_begin="1024" data_begin="1760" length="64" time="1"/> <single_mapping origin_block="1152" data_block="1824" time="1"/> <single_mapping origin_block="2047" data_block="1825" time="1"/> </device> <device dev_id="3" mapped_blocks="72" transaction="2" creation_time="1" snap_time="1"> <single_mapping origin_block="0" data_block="1754" time="1"/> <single_mapping origin_block="32" data_block="1755" time="1"/> <single_mapping origin_block="128" data_block="1756" time="1"/> <single_mapping origin_block="384" data_block="1757" time="1"/> <single_mapping origin_block="640" data_block="1758" time="1"/> <single_mapping origin_block="896" data_block="1759" time="1"/> <range_mapping origin_begin="1024" data_begin="1760" length="64" time="1"/> <single_mapping origin_block="1152" data_block="1824" time="1"/> <single_mapping origin_block="2047" data_block="1825" time="1"/> </device> </superblock> -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
