System backup (简体中文)

翻译状态：本文是 System backup 的翻译。上次翻译日期：2019-01-31。如果英文版本有所更改，则您可以帮助同步翻译。

常规性的备份系统和用户数据是非常重要的，比如说 /etc, /home, /var 这些目录。如果是服务器还有 /srv.

使用 Btrfs snapshots

详情请看 Btrfs#Snapshots 和 Snapper.

使用 LVM snapshots

详情请看 LVM#Snapshots 和 Create root filesystem snapshots with LVM.

使用 rsync

详情请看 rsync#As a backup utility.

使用 tar

See Full system backup with tar.

使用 SquashFS

详情请看 Full system backup with SquashFS.

能够启动（boot）的备份

Having a bootable backup can be useful in case the filesystem becomes corrupt or if an update breaks the system. The backup can also be used as a test bed for updates, with the testing repo enabled, etc. If you transferred the system to a different partition or drive and you want to boot it, the process is as simple as updating the backup's /etc/fstab and your bootloader's configuration file.

This section assumes that you backed up the system to another drive or partition, that your current bootloader is working fine, and that you want to boot from the backup as well.

更新 fstab

Without rebooting, edit the backup's fstab by commenting out or removing any existing entries. Add one entry for the partition containing the backup like the example here:

/dev/sdaX    /             ext4      defaults                 0   1

Remember to use the proper device name and filesystem type.

更新引导程序的配置文件

For Syslinux, all you need to do is duplicate the current entry, except pointing to a different drive or partition.

提示： Instead of editing syslinux.cfg, you can also temporarily edit the menu during boot. When the menu shows up, press the Tab key and change the relevant entries. Partitions are counted from one, drives are counted from zero.

For GRUB, it is recommended that you automatically re-generate the main configuration file. If you want to freshly install all grub files to somewhere other than /boot, such as /mnt/newroot/boot, use the --boot-directory flag.

Also verify the new menu entry in /boot/grub/grub.cfg. Make sure the UUID is matching the new partition, otherwise it could still boot the old system. Find the UUID of a partition with lsblk:

$ lsblk -no NAME,UUID /dev/sdb3

where you substitute the desired partition for /dev/sdb3. To list the UUIDs of partitions grub thinks it can boot, use grep:

# grep UUID= /boot/grub/grub.cfg

第一次启动

Reboot the computer and select the right entry in the bootloader. This will load the system for the first time. All peripherals should be detected and the empty folders in / will be populated.

Now you can re-edit /etc/fstab to add the previously removed partitions and mount points.