https://github.com/hyperblock/lvdiff
A pair of tools ( lvdiff/lvpatch ) to backup and restore LVM2 thinly-provisioned volumes.
lvdiff is a tool to dump the differential blocks of two LVM2 thinly-provisioned volumes.
The format of dump file is called HyperLayer. ( http://www.hyperblock.org/2017/06/16/hyperlayer/ )
Usage:
lvdiff <volume_A> <volume_B> [flags]
Flags:
-d, -- int32 checksum detect level. range: 0-3
0 means no checksum,
1 means only check head block,
2 means random check,
3 means scan all data blocks. (default 2)
-h, --help help for lvdiff
--meta set metadata (format as '$key:$value').
To set one more meta, use --meta aa:aa --meta bb:bb
lvpatch is a tool to patch volume's diff file (a set of volume's change blocks) to another thin-volume.
Usage:
lvpatch <new_volume_name> [flags]
Flags:
-h, --help help for lvpatch
-l, --lvbase string base logical volume
-g, --lvgroup string volume group
--no-base-check patch volume into base without calculate checksum.
In this section, we will use lvdiff to create an diff-block file of thin volume.
Assuming there is a thin-volume pool 'pool0' in volume group 'vg0'
- Create an snapshot sp0 of vol0
$ lvcreate -s -n sp0 /dev/vol0
- Write some data into vol0
$ mount /dev/vg0/vol0 /mnt/vg0/vol0
$ echo "hello world" > /mnt/vg0/vol0/hello
$ ..... //write some files to /dev/vg0/vol0
- dump diff file:
$ lvdiff -g vg0 --meta 'Author:BigVan (alpc_metic@live.com)' --meta 'Message: hello world' sp0 vol0 > test.diff
lvdiff will dump the different blocks between vol0 and sp0 and saved as test.diff. And SHA1 code will be shown in Stderr.
In this section, we will patch test.diff to a base volume 'vg1/sp0' which is identical with vg0/sp0 .
- Patch test.diff to vg1/sp0
$ cat test.diff | sudo ./lvpatch -g vg1 -l sp0 vol0_new
It will restore thin volume /dev/vg1/vol0_new
Use command lvs to check current volumes in your computer. If an volume is inactive, use command lvchange -ay -K [volume path] to active it before mount.
https://github.com/hyperblock/lvdiff
lvdiff/lvpatch 是一组用于对LVM自动精简配置(Thin Provisioning)的逻辑卷进行差异比较和补丁的工具。使用 lvdiff 可以将两个逻辑卷的差异数据块形成二进制文件导出,再通过 lvpatch 可将差异文件拼凑至另外的逻辑卷之上，实现逻辑卷的迁移。
通过lvdiff导出的文件格式称作 HyperLayer ( http://www.hyperblock.org/2017/06/16/hyperlayer/ )
lvdiff 用于将指定的两个逻辑卷A和B之间的差异数据块导出成二进制文件。
Usage:
lvdiff <volume_A> <volume_B> [flags]
Flags:
-d, -- int32 checksum detect level. range: 0-3
0 means no checksum,
1 means only check head block,
2 means random check,
3 means scan all data blocks. (default 2)
-h, --help help for lvdiff
--meta set metadata (format as '$key:$value').
To set one more meta, use --meta aa:aa --meta bb:bb
lvpatch 用于将lvdiff导出的结果拼凑到另一个 逻辑卷base 之上并形成新卷。当 逻辑卷base 与 原逻辑卷B 的数据一致时，可实现逻辑卷A的异地恢复。
Usage:
lvpatch <new_volume_name> [flags]
Flags:
-h, --help help for lvpatch
-l, --lvbase string base logical volume
-g, --lvgroup string volume group
--no-base-check patch volume into base without calculate checksum.
这一部分为使用 lvdiff 的示例。 假设在逻辑卷组 'vg0' 中有精简配置池 'pool0'
- 建立 vol0 的快照 sp0
$ lvcreate -s -n sp0 /dev/vol0
- 向 vol0 中写入数据
$ mount /dev/vg0/vol0 /mnt/vg0/vol0
$ echo "hello world" > /mnt/vg0/vol0/hello
$ ..... //write some files to /dev/vg0/vol0
- 导出 vol0 与 sp0 之间的差异数据块，同时添加一些导出信息:
$ lvdiff -g vg0 --meta 'Author:BigVan (alpc_metic@live.com)' --meta 'Message: hello world' sp0 vol0 > test.diff
vol0 和 sp0 之间的差异数据将被保存为 test.diff . 同时，该文件的 SHA1 结果将被输出至 Stderr.
这一部分将把 test.diff 拼接到与上一节中 vg0/sp0 一致的另一逻辑卷 'vg1/sp0' 上，实现 vg0/vol0 的异地恢复。 3. 将 test.diff 拼凑到 sp0 之上
$ cat test.diff | sudo ./lvpatch -g vg1 -l sp0 vol0_new
新卷的名字为 vg1/vol0_new.
使用命令 lvs 用于列出当前机器上存在的逻辑卷. 如果某一逻辑卷在挂在前未激活, 需要通过 lvchange -ay -K [volume path] 命令去激活该卷。