Working with Subversion

Checking Status and Updating Multiple Working Copies

Say you have a bunch of directories, each of which contains a working copy of a different repository. When you sit down to work at this machine you might want to ensure that all of your working copies are updated. Rather than doing this by hand, you can go to the parent directory of all of the working copies (say, "~/PROJECTS") use this bash one-liner:

for X in `find . -maxdepth 2 -type d -name ".svn" | cut -d / -f 2`; do svn update ./$X; done

Shell script novices can note that this one-liner uses the commands find and cut to first find all of the subdirectories which are Subversion working copies (using find ) and then to return a list of the directory names (using cut). The for X in ...; do ...; done part executes the commands between the do and the done for each element in X (which is the list of text elements returned by surrounding the find ...| cut ... piece with `.

Migrating from One Server to Another

If your Subversion repository happened to be running on a 6 year old Linux box built from spare parts, some of which are more than 6 years old, and this machine just so happens to fail, how can you re-instantiate your repository on a new machine?

First Hope That You Have Backed Up the Repository

Here is an example cron.daily script that I used to backup my old bad server repository and to transfer the dumped files to another machine via ssh:

  
#! /bin/sh  

cd /home/svn/repos
for X in *; do svnadmin dump $X > /TEMP/SVNDUMP/${X}dump; done  
rsync -auvzr -e ssh  /TEMP/SVNDUMP user@backupdestination.edu:~/
cd
  

Next Create a New Directory Structure for Your Repositories

TODO

Create New Repositories

TODO

Load the Backups into the New Repositories

TODO

Now you are ready to go.

For Clients

Once the new subversion server is running and has loaded the backup files, you need to "switch" the repository to which your working copies point by using the following svn switch command:

cd WorkingCopy
svn info #find the name of the old repository by looking at the URL field and use it below.
svn switch --relocate svn+ssh://oldbadserver.edu/home/svn/repos/WorkingCopy \
                      svn+ssh://newgoodserver.edu/Users/svn/Repos/WorkingCopy

Then you'll want to do svn -u st within each of the Working Copy directories to make sure the switch worked out:
for X in `find . -maxdepth 2 -type d -name ".svn" | cut -d / -f 2`; do svn update ./$X; done
And if it looks ok, you can get back to work.

Troubleshooting

Sometimes, if you've changes a bunch of stuff in the Working Copy while the new server was being re-populated or the server failed after a commit from you but before cron.daily can run, you'll get an error message about "no such revision" or something. This means that you have to check out a new copy of the repository, and to by hand, add stuff from your (assumed newer) Working Copy to it, and then to commit the new working copy with your changes. Say, I had a problem with my BIB directory, the workflow would go something like this:

mv BIB oldBIB
svn co file:///Users/svn/Repos/BIB BIB
diff -ruNp --exclude=.svn BIB oldBIB > file.patch
##(then look at the file.patch to see what the differences were)
patch -p0 -u < file.patch 

Then you can do svn -u st and svn commit to get the new changes to the Working Copy uploaded.