Go to file
Ming-Hung Tsai e3a646e4d2 [dbg] Improve error resilience of debugging tools
Do not open the metadata. The tool interprets user specified blocks one-by-one.
Thus, there's no need to preload the metadata structures.

Also remove the unused --ignore-metadata-space-map option. It was designed
to control the loading of space maps with the old metadata constructors.
2021-02-18 00:00:55 +08:00
autoconf more build stuff 2011-12-09 12:54:51 +00:00
base [dbg] Hide implementations of shared components 2021-02-04 14:28:17 +08:00
bin [build] Enable building the dev-tools for functional tests 2021-01-12 16:08:51 +08:00
block-cache [cache_writeback] Support offset within the source and destination devices 2021-01-20 12:02:13 +08:00
caching [dbg] Improve error resilience of debugging tools 2021-02-18 00:00:55 +08:00
contrib autoconf: allow a user to override ar 2020-07-25 15:16:28 -07:00
doc [thin_journal_check] Checks journal of block manager activity. 2018-09-24 14:51:46 +01:00
era Fix regression where era_restore wouldn't work with devices. 2021-02-17 15:15:57 +00:00
features [functional-tests] era_check tests 2017-08-30 14:30:11 +01:00
ft-lib [ft-lib/bcache] rename raise() -> raise_() 2019-06-05 15:02:05 +01:00
functional-tests [functional-tests] Port 3 --auto-repair tests from Scheme to Rust 2020-08-12 13:03:01 +01:00
lib gmock stub 2013-03-22 10:55:55 +00:00
man8 [thin_check] rename --fix-metadata-leaks to --auto-repair 2020-08-12 10:45:20 +01:00
persistent-data [metadata_counter] Count under populated nodes if the option is provided 2020-11-24 18:18:21 +08:00
src [io_engine] Add Block::zeroed() constructor 2021-02-09 14:34:26 +00:00
tests [functional-tests] Update thin_delta help text 2021-01-12 02:50:46 +08:00
thin-provisioning [dbg] Improve error resilience of debugging tools 2021-02-18 00:00:55 +08:00
ui [thin_show_metadata] ncurses render 2016-02-26 12:50:17 +00:00
unit-tests [cache_writeback] Support offset within the source and destination devices 2021-01-20 12:02:13 +08:00
xml_metadata add some example metadata dumps 2011-11-16 12:17:23 +00:00
.gitignore [rust tools] Get the tools version from autoconf 2020-06-09 10:23:52 +01:00
Cargo.lock [io_engine] Add Block::zeroed() constructor 2021-02-09 14:34:26 +00:00
Cargo.toml [io_engine] Add Block::zeroed() constructor 2021-02-09 14:34:26 +00:00
CHANGES [build] Update CHANGES file 2020-08-12 10:35:03 +01:00
configure.ac version.rs includes VERSION directly. 2021-02-04 10:00:32 +00:00
COPYING Add copyright 2011-12-06 13:43:44 +00:00
get-gmock.sh update get-gmock script. 2016-06-07 11:15:35 +01:00
main.cc [base] introduce a command type that gets registered with the app 2016-01-08 12:51:52 +00:00
Makefile.in [cache_debug] Fork thin_debug into cache_debug 2021-02-04 14:29:18 +08:00
mk_release make mk_release executable 2012-03-05 11:46:20 +00:00
README.md [thin_metadata_pack/unpack] Replace C++ implementation with a Rust one. 2020-06-09 09:15:00 +01:00
rustfmt.toml [thin_metadata_pack/unpack] Replace C++ implementation with a Rust one. 2020-06-09 09:15:00 +01:00
TODO.org Add a TODO file 2013-04-23 11:18:21 +01:00
VERSION bump version to 0.9.0 2020-08-12 10:46:26 +01:00
version.h.in version.h.in 2011-12-15 14:58:25 +01:00

Introduction

A suite of tools for manipulating the metadata of the dm-thin, dm-cache and dm-era device-mapper targets.

Requirements

A C++ compiler that supports the c++11 standard (eg, g++). The Boost C++ library. The expat xml parser library (version 1). The libaio library (note this is not the same as the aio library that you get by linking -lrt) make, autoconf etc.

A couple of non-essential tools are written in rust, and will require cargo and rustcc to be installed:

thin_metadata_pack
thin_metadata_unpack

There are more requirements for testing, detailed below.

Building

autoconf
./configure
make
sudo make install

Building Rust tools

sudo make install-rust-tools

Quick examples

These tools introduce an xml format for the metadata. This is useful for making backups, or allowing scripting languages to generate or manipulate metadata. A Ruby library for this available; thinp_xml.

To convert the binary metadata format that the kernel uses to this xml format use thin_dump.

thin_dump --format xml /dev/mapper/my_thinp_metadata

To convert xml back to the binary form use thin_restore.

thin_restore -i my_xml -o /dev/mapper/my_thinp_metadata

You should periodically check the health of your metadata, much as you fsck a filesystem. Your volume manager (eg, LVM2) should be doing this for you behind the scenes.

thin_check /dev/mapper/my_thinp_metadata

Checking all the mappings can take some time, you can omit this part of the check if you wish.

thin_check --skip-mappings /dev/mapper/my_thinp_metadata

If your metadata has become corrupt for some reason (device failure, user error, kernel bug), thin_check will tell you what the effects of the corruption are (eg, which thin devices are effected, which mappings).

There are two ways to repair metadata. The simplest is via the thin_repair tool.

thin_repair -i /dev/mapper/broken_metadata_dev -o /dev/mapper/new_metadata_dev

This is a non-destructive operation that writes corrected metadata to a new metadata device.

Alternatively you can go via the xml format (perhaps you want to inspect the repaired metadata before restoring).

thin_dump --repair /dev/mapper/my_metadata > repaired.xml
thin_restore -i repaired.xml -o /dev/mapper/my_metadata

Development

Autoconf

If you've got the source from github you'll need to create the configure script with autoconf. I do this by running:

autoreconf

Enable tests

You will need to enable tests when you configure.

./configure --enable-testing

Unit tests

Unit tests are implemented using the google mock framework. This is a source library that you will have to download. A script is provided to do this for you.

./get-gmock.sh

All tests can be run via:

make unit-test

Alternatively you may want to run a subset of the tests:

make unit-tests/unit_tests
unit-tests/unit_tests --gtest_filter=BtreeTests.*

Functional tests

A bunch of high level tests are implemented in the functional-tests directory. These tests are written in Scheme. To run them you'll need to install chezscheme (http://www.scheme.com/). There is no longer a dependency on the ThunderChez library.

Make sure the tools that you wish to test are in your PATH.

Then,

cd funtional-tests
./run-tests run

Other command are help and list.

The test framework places temporary files under ./test-output/. By default the tests tidy up after themselves, just leaving a log file for each test. You can turn this off by using the --disable-unlink flag if you want all the artifacts left.

Dump Metadata

To dump the metadata of a live thin pool, you must first create a snapshot of the metadata:

$ dmsetup message vg001-mythinpool-tpool 0 reserve_metadata_snap

Extract the metadata:

$ sudo bin/thin_dump -m /dev/mapper/vg001-mythinpool_tmeta
<superblock uuid="" time="1" transaction="2" data_block_size="128"nr_data_blocks="0">
    <device dev_id="1" mapped_blocks="1" transaction="0" creation_time="0" snap_time="1">
        <single_mapping origin_block="0" data_block="0" time="0"/>
    </device>
    <device dev_id="2" mapped_blocks="1" transaction="1" creation_time="1" snap_time="1">
        <single_mapping origin_block="0" data_block="0" time="0"/>
    </device>
</superblock>

Finally, release the root:

$ dmsetup message vg001-mythinpool-tpool 0 release_metadata_snap