清理 APFS 快照的shell脚本

背景

macOS 从 10.13 High Sierra开始，引入了 APFS(Apple File System) 替代原先的 HFS+ 作为默认磁盘格式。

笔者觉得最大的特色在于 写时拷贝(Copy-on-Write) 和 快照(Snapshots)。对于前者，以后有机会笔者再写文阐述，本文主要针对后者。

快照的引入，可以方便并且快速地恢复到过去的某个时间节点，它与 时间机器(Time Machine) 配合起来，可以极大程度的保证数据安全。

但快照也导致一个不良后果，即占据了大量的磁盘空间。比如明明没使用很多文件，怎么磁盘空间耗去大半。

查看快照

这里利用到 tmutil 这个命令，通过查询 man 手册，发现它全称为 Time Machine utility，即原用于时间机器。

$ tmutil listlocalsnapshots /

Snapshots for volume group containing disk /:
com.apple.TimeMachine.2020-11-29-004329.local
com.apple.TimeMachine.2020-11-29-014637.local
com.apple.TimeMachine.2020-11-29-024241.local
com.apple.TimeMachine.2020-11-29-034330.local
com.apple.TimeMachine.2020-11-29-044145.local
com.apple.TimeMachine.2020-11-29-054542.local
com.apple.TimeMachine.2020-11-29-064456.local
com.apple.TimeMachine.2020-11-29-074846.local
com.apple.TimeMachine.2020-11-29-084356.local
com.apple.TimeMachine.2020-11-29-094633.local
com.apple.TimeMachine.2020-11-29-104339.local
com.apple.TimeMachine.2020-11-29-114752.local
com.apple.TimeMachine.2020-11-29-134250.local
com.apple.TimeMachine.2020-11-29-144214.local
com.apple.TimeMachine.2020-11-29-154417.local
com.apple.TimeMachine.2020-11-29-164352.local
com.apple.TimeMachine.2020-11-29-174500.local
com.apple.TimeMachine.2020-11-29-184606.local
com.apple.TimeMachine.2020-11-29-194225.local
com.apple.TimeMachine.2020-11-29-204725.local
com.apple.TimeMachine.2020-11-29-214338.local
com.apple.TimeMachine.2020-11-29-224417.local
com.apple.TimeMachine.2020-11-29-234647.local

通过 df -th 查看磁盘剩余 153GB

清理快照

这里祭出一行shell脚本

(tmutil listlocalsnapshots / | awk -F. '{print snapshot; done

Deleted local snapshot '2020-11-29-004329'
Deleted local snapshot '2020-11-29-014637'
Deleted local snapshot '2020-11-29-024241'
Deleted local snapshot '2020-11-29-034330'
Deleted local snapshot '2020-11-29-044145'
Deleted local snapshot '2020-11-29-054542'
Deleted local snapshot '2020-11-29-064456'
Deleted local snapshot '2020-11-29-074846'
Deleted local snapshot '2020-11-29-084356'
Deleted local snapshot '2020-11-29-094633'
Deleted local snapshot '2020-11-29-104339'
Deleted local snapshot '2020-11-29-114752'
Deleted local snapshot '2020-11-29-134250'
Deleted local snapshot '2020-11-29-144214'
Deleted local snapshot '2020-11-29-154417'
Deleted local snapshot '2020-11-29-164352'
Deleted local snapshot '2020-11-29-174500'
Deleted local snapshot '2020-11-29-184606'
Deleted local snapshot '2020-11-29-194225'
Deleted local snapshot '2020-11-29-204725'
Deleted local snapshot '2020-11-29-214338'
Deleted local snapshot '2020-11-29-224417'
Deleted local snapshot '2020-11-29-234647'

再次通过 df -th 查看磁盘剩余 159GB，释放出 6GB 空间