Server migration cheat sheet

Have history with timestamps

May not be enabled by default on a new server

• ~/.bash_profile:

  if [ -f ~/.bashrc ]; then
      . ~/.bashrc
  fi

• ~/.bashrc:

  # Enable timestamp in history
  export HISTTIMEFORMAT="%F %T "
  # Make history append instead of overwrite
  shopt -s histappend
  # Increase history size
  export HISTSIZE=1000000
  export HISTFILESIZE=2000000

  (optional) Automatically cd to a specific folder on every SSH connection

  cd ~/domains

Dump database into file on old server

Before copying over all of your files, you may want to dump the database so that it's copied over as well.

mysqldump -h database.example.com -P 33000 -u db_usr -p db_name > /var/www/dir/db_dump.sql

• -h: if your database is on a remote server, provide hostname or IP address; else do not provide -h at all
• -P: if your server port is non-standard; else do not provide -P at all
• -u: database user
• -p: prompt the password; if you want you can provide your password explicitly as -pMYPASSWORD, but that may compromise it

Copy folder from old server to new server

Copying files from old server? Might as well include database dump. See above.

Below copies dir from /var/www on old server to /var/www on new server.

• SCP

  scp -P 2222 -r -p username@oldserver:/var/www/dir /var/www

  • -P: non-standard SSH port
  • -r: recursive, i.e. everything inside given folder including subfolders
  • -p: preserve original timestamps

• Rsync

  rsync -avh -e 'ssh -p 2222' username@oldserver:/var/www/dir /var/www

  • -v: verbose, print information about progress of the transfer and files being copied
  • -h: human-readable, used with -v, makes file sizes easier to read
  • -a: archive, shorthand for the following:
    • -r: recursive
    • -l: copy symlinks as symlinks, do not dereference
    • -p: preserve permissions (file permission bits)
    • -t: preserve original timestamps.
    • -g: preserve original group ownership
    • -o: preserve original owner
    • -D: preserve device files and special files:
      • --devices – copy device files
      • --specials – copy special files like named pipes and sockets

Restore database on new server

mysql -u db_usr -p db_name < /var/www/dir/db_dump.sql