我输入了以下命令：
cd /var/discourse
git pull
./launcher rebuild app
我收到了如下警告信息：
位于 /var/lib/docker 的磁盘上可用空间少于 5 GB。
文件系统 大小 已用 可用 使用率 挂载点
/dev/vda 25G 20G 4.4G 82% /
(Y/N) y (y/N) y 您是否希望通过清理系统中的 Docker 镜像和容器来尝试释放空间？
警告！这将删除：
- 所有已停止的容器
- 未被任何容器使用的网络
- 所有悬空镜像
- 所有构建缓存
您确定要继续吗？[Y/N] N
如果清理成功，您现在可以尝试重试
根据以下主题：
我输入了以下命令：
sudo ./launcher rebuild app --skip-prereqs
我的网站目前无法正常运行。
请告诉我该如何处理！
在执行 sudo ./launcher rebuild app --skip-prereqs 之前，我已经备份了我的网站。
Why did you answer N and cancel the cleanup? That should make space for you to rebuild without using --skip-prereqs
After doing “./launcher rebuild app --skip - prereqs”, the site did not open and I ran “./launcher rebuild app” and chose y …
Is there a way to restore the site?
Were you able to make space to complete the rebuild?
If the rebuild failed and it didn’t delete the old docker image then you can probably just
cd /var/discourse
./launcher start app
To get back to the old version, but you clearly have a storage issue you need to tackle.
cd / var / discourse
./ launcher start app
With the commands above the site is now to stand up, Thank you very much.
How can I update the site after all?
I’m sorry for the novice question.
After launching, I typed the following command again, but this time the warning message was not displayed and started rebuilt, and the site did not open again.
cd / var / discourse
git pull
./launcher rebuild app
Currently the site is standing up with the following command again.
cd / var / discourse
./ launcher start appStill don’t know how to fix this 
How much space does your server have in total?
Where are you using it?
We can’t even begin to advise you on this without some information to go on. It may well be outside the scope of the support we provide here, but without some data it’s impossible to even say that definitively.
My DigitalOcean’s droplet is “1 GB Memory / 25 GB Disk / SGP1 - Ubuntu 16.04.4 x64“ 
Does anyone know the way to fix a storage issue which what happend to me 
This is a server maintenance issue as opposed to a Discourse issue.
Use df whilst connected via SSH to look at free vs available space - what else do you have on this server? How big are your backups?
The result of df.
Filesystem 1K-blocks Used Available Use%
udev 498688 0 498688 0%
tmpfs 101604 10840 90764 11%
/dev/vda1 25227048 8893416 16317248 36%
tmpfs 508012 0 508012 0%
tmpfs 5120 0 5120 0%
tmpfs 508012 0 508012 0%
/dev/vda15 106858 3437 103421 4%
tmpfs 101604 0 101604 0%
overlay 25227048 8893416 16317248 36%
shm 524288 8 524280 1%
The size of backup of my site is 57.1MB
According to that you’ve got 16GB free, which is plenty. You should be able to upgrade fine without problem now.
cd /var/discourse
./launcher rebuild app
Once you’ve done the above there’s no need to do another upgrade on the web interface, this will do it all.
hmmm… it does not also work…
…
FAILED -------------------- Pups::ExecError: cd /var/www/discourse && su discourse -c 'bundle exec rake db:migrate' failed with return #<Process::Status: pid 10681 exit 1> Location of failure: /pups/lib/pups/exec_command.rb:112:in `spawn' exec failed with the params {"cd"=>"$home", "hook"=>"bundle_exec", "cmd"=>["su discourse -c 'bundle install --deployment --verbose --without test --without development --retry 3 --jobs 4'", "su discourse -c 'bundle exec rake db:migrate'", "su discourse -c 'bundle exec rake assets:precompile'"]} 150075aac134b18e5415078c15bcb72aa29e947e42310acc34e0b9b9e89ff95e ** FAILED TO BOOTSTRAP ** please scroll up and look for earlier error messages, there may be more than one
When I did “git pull”, it showed “Already up-to-date”. Is it relevant to this problem?
What version is specified in /var/discourse/containers/app.yml
Is it tests-passed? or something else?
How did you install Discourse? Did you follow the official installation guide?
Version which is written in /var/discourse/containers/app.yml is “tests-passed”.
But this is commented out by default.
#version: tests-passed
Yes I installed Discourse followed official installation guide.
I have already managed site for 3 months without any such update error.
Is this error perhaps what I should fix in ./launcher rebuild app?
2018-11-10 20:57:05.046 UTC [85] postgres@postgres ERROR: database "discourse" already exists
Hmmm still confusing
That’s an odd error. Have you rebuilt more than once?
We used to see that when people did the postgres upgrade and it failed, right?
Yes I had rebuilt several times 