So, doing an apt-get upgrade on a Debian or Ubuntu machine sometimes does more than you want at once.

See this upgrade example I encountered just now:

# apt-get upgrade
The following packages will be upgraded:
  curl dpkg ifupdown iproute libcurl3 libcurl3-gnutls libgnutls26
  libmysqlclient18 libsnmp-base libsnmp15 libssl1.0.0 libxml2 linux-firmware
  linux-generic-lts-quantal mysql-client-5.5 mysql-client-core-5.5 mysql-common
  mysql-server mysql-server-5.5 mysql-server-core-5.5 openssh-client
  openssh-server openssl tzdata update-manager-core whoopsie
26 upgraded, 0 newly installed, 0 to remove and 2 not upgraded.
Need to get 63.0 MB/63.0 MB of archives.

I do want to upgrade the mysql, but I don't want to combine that with the other upgrades. Why? Because of the install cycle:

  • Download
  • Unpack/prepare
  • Setup

During the prepare cycle, some daemons are stopped and they are first started during the setup cycle. That means that the mysql server may be down for a longer period of time than necessary.

To mitigate that, we can attempt to upgrade only the mysql-server package:

# apt-get install mysql-server
The following packages will be upgraded:

However, that includes only the mysql-server package and not the related packages (libs, core, mysql-client). That would be a bad idea.

So, how do we force it to install only mysql-server and the related packages?

Here, aptitude comes to the rescue:

# echo `aptitude search -F%p '?reverse-depends(mysql-server) ?installed'`
adduser debconf libc6 libdbi-perl libstdc++6 libwrap0 lsb-base mysql-client-5.5
mysql-common mysql-server-5.5 mysql-server-core-5.5 passwd perl psmisc upstart

Or, better yet:

# echo `aptitude search -F%p '?reverse-depends(mysql-server) ?upgradable'`
mysql-client-5.5 mysql-common mysql-server-5.5 mysql-server-core-5.5

That's a much nicer list. Fire away:

# aptitude install '?reverse-depends(mysql-server) ?upgradable'
The following packages will be upgraded: 
  mysql-client-5.5 mysql-common mysql-server mysql-server-5.5 mysql-server-core-5.5 
5 packages upgraded, 0 newly installed, 0 to remove and 23 not upgraded.

aptitude upgrade updates ubuntu debian