Migrate install to new VPS...

I have a ChunkHost Virtual Private Server (or VPS), and I ran into a predicament. I will admit my Debian knowledge is ever increasing, and now that sid has “thawed” its package selection is much more mercurial. Currently, this poses a problem for my web sites hosted on the VPS: amberandtrey.us, and this site (eldon.me). At the moment, Sid is going through a particular transition: apache-2.2 to apache-2.4. Thus many of the packages I need are in flux, and on any given day it could be horribly broken. I decided to switch back to Wheezy, but there’s no real way to downgrade. I’d have to reinstall.

ChunkHost gives a really (insidiously) easy way to fire up a new VPS (called a “chunk”). Within minutes I had my betachunk. My first chunk was called “alphabouncer” by me because I originally intended it to be an IRC bouncer (so if someone were to attack my IP address they’d be attacking my chunk, not my home IP address), but I digress. It wasn’t a simple matter of just copying files; I had to back up the MySQL databases, back up the WordPress files, copy my WeeChat configuration, restore it all, set the DNS server to point both domains at the new IP address, and coax it into working.

NOTE: All of the commands were performed within my backup directory, /root/backup/2013-06-15, unless otherwise noted.

  1. The first thing I did was to backup the databases. Since both websites use their own databases within the confines of the single MySQL instance, I needed to ensure the mysqldump command captured all databases. To conserve space, I ran the results through bzip2. The command I used was this:
    mysqldump -u root -p --all-databases --events | bzip2 -c - > websites_$(date +%F).sql.bz2

    All events may not have been necessary (and possibly problematic if the database is in active use at the time of the dump), but mysqldump will issue a warning if that flag is not passed. These are small enough databases that grabbing the events should not pose a problem.

  2. The next task was to back up the WordPress files. These lived in two places: /usr/share/wordpress for amberandtrey.us, and /var/www/eldon.me. I wanted to move amberandtrey.us to /var/www/amberandtrey.us to be more orthogonal with my directory structure, but more on that below. I also grabbed /etc and /root in case I needed them (I definitely did, mainly for SSL certificates, apache2 and WordPress server files). In order to back these up, I just used the standard tar commands:
    tar -cvjf amberandtrey.us_$(date +%F).tar.bz2 /usr/share/wordpress tar -cvjf eldon.me_$(date +%F).tar.bz2 /var/www/eldon.me/ tar -cvjf etc_$(date +%F).tar.bz2 /etc tar -cvjf alphabouncer-root_$(date +%F).tar.bz2 --exclude=backup --exclude=downloads --exclude=.cpan /root

    I used the excludes because the destination is in /root/backup, and I didn’t need to have all the cruft lying around on the new server.

  3. To copy my Weechat configuration, I created a matching username on the new VPS (betachunk). Rather than tar up my ~/.weechat directory, I used Midnight Commander (or “mc” for short) on alphabouncer to select the directory and copy it over. Since the two VPSes are in the same data center, I thought the transfer would occur quickly. It did, but some of the logs were still outrageously large, so it took a few minutes to complete.
  4. Restoring it all was a little tricky, compounded by the fact that I wanted to make minor structural changes to some of the WordPress directory layout. I copied the contents of alphabouncer:/root/backup/2013-06-15/* to betachunk:/root/backup/2013-06-15/. I can’t remember exactly, but I think I used mc to copy the entire backup directory over. I first changed directory (“cd”) into the backup directory, and untarred the etc backup file to the current directory (a nonstandard location) because I was going to copy the files one at a time using the command:
    tar -xvf etc_2013-06-15.tar.bz2

    I first copied over all of my SSL files for both sites, and the StartCom (my cert provider) files as well. This included everything for /etc/ssl/certs and /etc/ssl/private.

  5. Next I unpacked amberandtrey.us, created the directory where I wanted the files to ultimately live, and move the resulting files into that directory:
    tar -xvf amberandtrey.us_2013-06-15.tar.bz2 mkdir -p /var/www/amberandtrey.us mv usr/share/wordpress/* /var/www/amberandtrey.us

    I then repeated the process with eldon.me:

    tar -xvf eldon.me_2013-06-15.tar.bz2
    mv var/www/eldon.me /var/www/
  6. The next step was the tricky part. I had to restore all databases, but the database server MySQL hadn’t been installed yet (installing the wordpress package did NOT resolve this dependency!):
    aptitude install mysql-server

    Installing the mysql-server package prompted me to set the root password, but I still needed to copy the /etc/mysql/debian.cnf file from the previous installation. This allowed the MySQL daemon to start cleanly.

  7. The final step in transferring the WordPress sites to betachunk was to set up the /etc/wordpress/config-*.php files. Copying them from the restored /etc backup location, and we were almost in business.
  8. Since I was using SNI (Server Name Indication, see my KeePassX database merge topic for a brief discussion of this), I’d need to tie the new IP address to both domains. ChunkHost has a neat little DNS tool that can be used to do this. Since at my domain registrar (GoDaddy, I use them because they were convenient when I bought my first domain, and inertia keeps me with them) already has the ChunkHost nameservers for both domains, I just needed to update ChunkHost’s DNS server with the new IP address, and I was running!

Well, I thought I was running. amberandtrey.us worked no problem, but eldon.me had issues. Apparently I have the error log for eldon.me in a weird file (it’s not /var/log/eldon.me-error.log, like it probably should be). This has now been corrected. Anyway, I had to run “ls -al /var/log/apache2/” in a watch command to see what file was changing when I tried accessing eldon.me (and was getting a 500 Internal Server Error):

watch -n 1 ls -al /var/log/apache2

I saw the nonstandard log file (eldon.me-ssh-error.log) changed size and modification date/time, so I investigated that file. I found these errors:

[Sat Jun 15 03:33:14 2013] [error] [client] PHP Warning: require_once(/etc/wordpress/config-eldon.me.php): failed to open stream: Permission denied in /var/www/eldon.me/wp-config.php on line 19, referer: https://eldon.me/wp-admin/post-new.php [Sat Jun 15 03:33:14 2013] [error] [client] PHP Fatal error: require_once(): Failed opening required '/etc/wordpress/config-eldon.me.php' (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/eldon.me/wp-config.php on line 19, referer: https://eldon.me/wp-admin/post-new.php

That led me to believe that /etc/wordpress/config-eldon.me.php did not have the correct permissions. I changed the ownership to www-data, and set the permissions to match the config-amberandtrey.us.php. Now eldon.me works!

Whew, what a long post! It took me longer to write than I would have expected because I ran into the problems on eldon.me (the server providing the WordPress post form I’m using). We’ll see if it lets me post it!