查看“Btrfs”的源代码

== 备份 ==

[[#dosnap|dosnap]] 可用于定时备份。

备份到移动硬盘：
<syntaxhighlight lang=bash>
sudo btrfs send -p /mnt/_snapshots/%home/{2021-04-30T23-00-57-auto,2021-05-09T23-00-01-auto} | pv |
     sudo btrfs receive /path/to/backupdrive/home
</syntaxhighlight>

== 相关程序 ==

以下是一些好用的 Btrfs 相关的程序。

=== [https://github.com/weirane/dosnap/ dosnap] ===

我写的一个类似 [https://github.com/openSUSE/snapper/ snapper] 的自动备份程序。在配置 <code>/etc/dosnap.toml</code> 中指定路径信息和保留备份数量，用 [[systemd]] timer 自动创建和清理备份。

=== [https://github.com/kilobyte/compsize compsize] ===

查看 <code>/</code> 的压缩类型和压缩前后的大小

 sudo compsize /

=== [https://github.com/knorrie/btrfs-heatmap btrfs-heatmap] ===

查看 <code>/mountpoint</code> 的 heatmap

 sudo btrfs-heatmap /mountpoint

=== [https://github.com/speed47/btrfs-list btrfs-list] ===

查看树形的 snapshot 列表

<syntaxhighlight lang=bash>
sudo btrfs quota enable /
# 等待 quota rescan
sudo btrfs-list
sudo btrfs quota disable /
</syntaxhighlight>

=== btrfs-diff ===

查看第二个 subvolume 相对于第一个改变的文件

 sudo btrfs-diff /mnt/_snapshots/%home/snap /mnt/@home

脚本如下（拷贝自 https://serverfault.com/a/580264<nowiki/>）

<syntaxhighlight lang=bash>
set -eu

usage() {
    echo "Usage: $0 <older-snapshot> <newer-snapshot>" >&2
    exit 1
}

[ $# -eq 2 ] || usage "Incorrect invocation"
snapshot_old=$1
snapshot_new=$2

[ -d "$snapshot_old" ] || usage "$snapshot_old does not exist"
[ -d "$snapshot_new" ] || usage "$snapshot_new does not exist"

old_transid=$(btrfs subvolume find-new "$snapshot_old" 9999999)
old_transid=${old_transid#transid marker was }
[ "$old_transid" -gt 0 ] || usage "Failed to find generation for $snapshot_new"

btrfs subvolume find-new "$snapshot_new" "$old_transid" | sed '$d' | cut -f17- -d' ' | sort | uniq
</syntaxhighlight>

[[Category:命令行]]