有三篇教程
mac上本来双盘COPY是很简单的，打开diskutil，加载两个磁盘，对着要恢复的盘，右键：选择恢复，可以选择 img/dmg文件，也可以选择已经 mount的磁盘。然而在恢复树莓的时候，一直失败【忘了截图了】
于是找到了教程1，教你怎么在命令下行备份，方法很简单，就2步
1、diskutil list，查看你的SD卡对应的是哪个磁盘，
2、备份：sudo dd if=/dev/rdisk1 of=/path/to/backup.img bs=1m
恢复：sudo dd if=/path/to/backup.img of=/dev/rdisk1 bs=1m
3、如果觉得太大，还可以gzip
备份：sudo dd if=/dev/rdisk1 bs=1m | gzip > /path/to/backup.gz
恢复：gzip -dc /path/to/backup.gz | sudo dd of=/dev/rdisk1 bs=1m
如果不想深究原因，那么看教程2，他会教你怎么弄，
1、df -h，看一下自己的SD卡是哪个，你会看到这时候显示的又和 diskutil list 不一样，df -h显示的都是 /dev/disk3s1 之类的
2、用diskutil unmount /dev/disk3s1，将它unmount掉
3、df -h 发现没有 /dev/disk3s1了
4、这时候参考 上面的rdisk方法，写入磁盘 /dev/rdisk[n] , 这个 n，就是刚才你 disk[3]s1 中的3，具体情况看你自己的sd卡是哪个盘
比如我这样：
sudo dd if=/Volumes/documents/2020-05-27-raspios-buster-lite-armhf.img of=/dev/rdisk3 bs=1m
1768+0 records in
1768+0 records out
1853882368 bytes transferred in 24.396307 secs (75990287 bytes/sec)
写入成功。
我就只知其然不知其所以然了，也没有过多深究。有兴趣的话，可以看看上面的教程3
1、在接下来的时间里，尽量不再增加新的图片
2、写脚本，将现有图片全部迁移上云
3、后端先重写，理论上后端重写可以完全不影响前端的显示，而且我发现用到现在，整个后台，其实只用到了内容发布，其他的几乎都已经几年没有动用过了。博客已经成为了纯粹的内容发布平台
4、再重写前端。原来考虑的就是太多。所以到最后啥也没弄成。现在考虑的是后台用dcat-admin，可以少写上千行代码。
5、前台的评论也还是要写的。原来的评论，我还得登录后来进行删除或者怎么怎么样。准备后面直接接入：sandbox的微信，用它来发通知给我。这样就好办多了
6、后台的登录，也准备是用sandbox的微信来嫩，又感觉可以少写很多代码。也防止了别人乱登录。多开心的事情啊~
为什么要这样嫩呢？这样的话，代码就可以放到GIT上了。原来代码没有和附件分离，一搞就是几个G，有点恐怖。现在这样的话，会好很多了应该。
目前数据库也不大，只有20多M，还算好
看起来这个标题好象没啥，今天被折腾了好久
因为网络不好，所以在更新的时候一直更新不下来。再更新就报zip包出错，多次尝试都是这样。
删除vendor目录，再试也是这样
开始以为是墙的问题，毕竟压缩包都在github上，所以爬了梯子试了下，还是zip包出错
因为发现问题都是出现在load from cache，所以想了下，还是用composer clear-cache清空一下。然后composer global update，再回到本目录，进行composer update
一切OVER
这是一篇引用文章，原文来自：https://derflounder.wordpress.com/2020/01/18/creating-root-level-directories-and-symbolic-links-on-macos-catalina/，可能部分用户打不开，毕竟是wordpress.com。。。
我简单的COPY一下：
One of the changes which came with macOS Catalina was the introduction of a read-only root volume for the OS. For users or environments which were used to using adding directories to the root level of the boot drive, this change meant they could no longer do that.
To address this need, Apple added a new method for creating directories at the root level which leverages Apple File System’s new firmlink functionality. Firmlinks are new in macOS Catalina and are similar in function to Unix symbolic links, but instead of only allowing travel one way (from source to destination) firmlinks allow bi-directional travel.
The use of firmlinks is exclusively reserved for the OS’s own use, but Apple has also made available what are called synthetic firmlinks. These synthetic firmlinks are how the OS enables folks to create directories and symbolic links on the read-only boot volume. For more details, please see below the jump.
To create a synthetic firmlink, you need to do the following:
1. Create a file in the /etc directory named synthetic.conf.
2. Make sure /etc/synthetic.conf has the following permissions:
- root: read, write
- wheel: read
- everyone: read
3. In /etc/synthetic.conf, define the name(s) of the empty directory or symbolic link you want to have appear at the root level.
4. After all desired entries have been made, save the /etc/synthetic.conf file.
5. Restart the Mac to apply the changes.
For example, /etc/synthetic.conf may look like this:
XML/HTML代码
- # create an empty directory named "foo" at / which may be mounted over
- foo
-
- # create a symbolic link named "bar" at / which points to
- # "System/Volumes/Data/bar", a writeable location at the root of the data volume
- bar System/Volumes/Data/bar
-
- # create a symbolic link named "baz" at / which points to "Users/me/baz"
- baz Users/me/baz
Note: In those cases where you’re creating a symbolic link and are including a path, the start point for the directory path is not /. Instead, it is the next directory level down.
To show how this works, I’ve created a directory containing installer packages located at /Users/Shared/installers.
To create a symbolic link at the root level named installers which points to /Users/Shared/installers, I would do the following:
1. Create the /etc/synthetic.conf file if it didn’t already exist.
2. Add the following entry to the /etc/synthetic.conf file:
|
1
|
installers Users/Shared/installers
|
3. Reboot the Mac.
Note: Whomever designed this came down on the “tabs” side of the “tabs vs. spaces” debate. When creating the separation between installers and Users/Shared/installers in the /etc/synthetic.conf file, you need to use tabs. If you use spaces instead, the synthetic firmlink won’t be created.
After the reboot, you should see a symbolic link named installers at the root level of the boot volume. When you navigate to it, you should see the contents of /Users/Shared/installers.
To remove the symbolic link, remove the relevant entry from /etc/synthetic.conf and then restart. After the reboot, the installers symbolic link should be missing from the root level of the boot volume.
For more information, please see the synthetic.conf man page. This is available by entering the following command in Terminal on macOS Catalina:
man synthetic.conf，可以看到内容大致这样：
XML/HTML代码
- SYNTHETIC.CONF(5) BSD File Formats Manual SYNTHETIC.CONF(5)
-
- NAME
- synthetic.conf
-
- SYNOPSIS
- synthetic.conf -- synthetic symbolic link and directory manifest
-
- DESCRIPTION
- synthetic.conf describes virtual symbolic links and empty directories to
- be created at the root mount point. Because the root mount point is read-
- only as of macOS 10.15, physical files may not be created at this loca-
- tion. All writeable paths must reside on the data volume, which is
- mounted at /System/Volumes/Data.
-
- synthetic.conf provides a mechanism for some limited, user-controlled
- file-creation at /. The synthetic entities described in this file are
- synthesized by the kernel during early system boot. They are not physi-
- cally present on the disk, but when the system is booted, they behave as
- if they were within certain parameters.
-
- synthetic.conf is intended to be used for creating mount points at /
- (e.g. for use as NFS mount points in enterprise deployments) and symbolic
- links (e.g. for creating a package manager root without modifying the
- system volume). synthetic.conf is read by apfs.util(8) during early sys-
- tem boot.
-
- FORMAT
- synthetic.conf specifies a single synthetic entity per line. Each line
- may have one or two columns, separated by a tab character. If a line has
- a single column, it denotes a virtual empty directory to be created at /.
- If a line has two columns, it denotes a symbolic link at / whose link
- target is given in the second column.
-
- In either case, the first column denotes the name of the entity to be
- created at /.
-
- A line beginning with the # character indicates a comment that is not
- parsed.
-
- SYNTHETIC ENTITIES
- Synthetic entities may not be deleted at runtime. In order to delete a
- synthetic entity, it must be removed from synthetic.conf, and the host
- must be rebooted.
-
- New files and directories may not be created within a synthetic empty
- directory.
-
- EXAMPLES
- # create an empty directory named "foo" at / which may be mounted over
- foo
-
- # create a symbolic link named "bar" at / which points to
- # "System/Volumes/Data/bar", a writeable location at the root of the data volume
- bar System/Volumes/Data/bar
-
- # create a symbolic link named "baz" at / which points to "Users/me/baz"
- baz Users/me/baz
-
- FILES
- /etc/synthetic.conf
-
- SEE ALSO
- apfs.util(8) shutdown(8) reboot(2)
-
- Darwin/macOS 2 July 2019 Darwin/macOS
参考 一下上面的内容，可以简单的试用一下。其实还行吧。（如果图片看不到。。就忍忍吧。）
---------
说白了就是几个事
1、在/etc目录下建一个 synthetic.conf 文件
2、设定的权限是：root 读写 wheel 读 everyone 读 ，权限值为：644
3、每行一条记录，目录名和目标引用的目录
比如你要在根目录下映射 一个 server，对应的是 /Users/gouki/Desktop，那就直接： server /Users/gouki/Desktop 就完事了
4、重要：改完得重启。。。。
--EOF
说白了，现在不支持根目录下的ln了。只能通过这个办法。如果有特别需要就试试吧。。。
----
：：划重点：：
1、权限是644
2、两个目录之间的间隔用tab，不是空格。原例子里用的是nano编辑 ，我用vim编辑的时候，tab居然无法输入（崩溃 ）
3、对应的目录前好象不需要 /
4、多测试几次吧。我重启了三次才搞定
