add metabackup

[qqqdan]

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What is changed, added or deleted? (Required)

Which TiDB version(s) do your changes apply to? (Required)

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By default, CHOOSE MASTER ONLY so your changes will be applied to the next TiDB major or minor releases. If your PR involves a product feature behavior change or a compatibility change, CHOOSE THE AFFECTED RELEASE BRANCH(ES) AND MASTER.

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• master (the latest development version)
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• v6.6 (TiDB 6.6 versions)
• v6.5 (TiDB 6.5 versions)
• v6.4 (TiDB 6.4 versions)
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• Delete files
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[ti-chi-bot]

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[shichun-0415]

Suggested change

	> 恢复操作会覆盖当前的 meta 文件，建议仅在 meta 文件丢失的情况下进行恢复。
	> 恢复操作会覆盖当前的 meta 文件，建议仅在 meta 文件丢失的情况下进行恢复。

[shichun-0415]

Suggested change

	如果 meta 文件丢失，可以使用以下方法恢复 meta 文件：
	如果 meta 文件丢失，可以使用以下方法恢复 meta 文件：

[ti-chi-bot]

@qqqdan: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-verify	66a8cd1	link	true	/test pull-verify

Full PR test history. Your PR dashboard.

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