btrfs 的备份¶

手动备份¶

转移home

sudo rsync -avrh --progress /home/ /mnt/backup/

timeshift and snapper¶

timeshift 备份根目录¶

snapper 备份子卷¶

snapper更加灵活。首先创建一个snapper的配置文件

sudo snapper -c <name of config> create-config <path-to-subvol>

例如对根目录的备份配置，snapper默认配置名是root

sudo snapper -c root create-config /

snapper默认会创建子卷/.snapshots，_~这不arch~主要是和之前的子卷布局不协调，所以

sudo umount /.snapshots
sudo rm -r /.snapshots
sudo btrfs subvolume delete /.snapshots
sudo mkdir /.snapshots
sudo mount -o subvol=/ /dev/nvme0n1p1 /mnt
sudo btrfs subvolume create /mnt/@snapshots

从快照中恢复¶

复杂的手动方法，要从live USB开始，就是安装arch时的live系统

sudo mount /dev/nvme0n1p6 /mnt
cd /mnt
sudo mv /mnt/@ /mnt/@.broken
sudo btrfs subvolume snapshot /mnt/@snapshots/{number}/snapshot /mnt/@
sudo btrfs subvolume delete /mnt/@.broken

不进入live系统的方法，看上去很危险，最好回滚后立刻重启

sudo mount -o subvol=/ /dev/nvme0n1p1 /mnt
sudo btrfs subvolume snapshot /mnt/@ /mnt/@bad
sudo btrfs subvolume delete /mnt/@
sudo btrfs subvolume snapshot /mnt/@snapshots/要恢复的快照号/snapshot /mnt/@

可以用脚本完成回滚

#!/bin/sh
set -e
if [[ x"$1" == x ]]; then
  echo "No snapshot number given." 1>&2
  echo "Usage: rollback [snapshot to rollback]" 1>&2
  exit 1
fi
root_dev=`findmnt -n -o SOURCE / | sed 's/\[.*\]//g'`
root_subvol=`findmnt -n -o SOURCE / | sed 's/.*\[\(.*\)\].*/\1/'`
echo ">= Rollback to #$1 on device $root_dev"
# create snapshot before
sudo snapper create --read-only --type single -d "Before rollback to #$1" --userdata important=yes
sudo mount -o subvol=/ $root_dev /mnt
# check enviornment
if [[ x"$root_subvol" == x/@ ]]; then
  echo "Warning: Not run in a snapshot, a subvolume @old will be created. You should consider remove it after reboot." 1>&2
  if [[ -d /mnt/@old ]]; then
    echo "Found last @old, remove it."
    sudo btrfs subvolume delete /mnt/@old >/dev/null
  fi
  sudo mv /mnt/@ /mnt/@old
else
  sudo btrfs subvolume delete /mnt/@ >/dev/null
fi
sudo btrfs subvolume snapshot /mnt/@snapshots/$1/snapshot /mnt/@ >/dev/null
sudo umount /mnt