Comment 1 for bug 427709

I saw insserv install this morning when doing updates:

...
2009-09-10 11:23:52 upgrade lsb-base 4.0-0ubuntu3 4.0-0ubuntu4
2009-09-10 11:23:57 upgrade lsb-release 4.0-0ubuntu3 4.0-0ubuntu4
2009-09-10 11:23:58 upgrade initscripts 2.86.ds1-61ubuntu16 2.87dsf-4ubuntu1
2009-09-10 11:23:58 upgrade sysv-rc 2.86.ds1-61ubuntu16 2.87dsf-4ubuntu1
2009-09-10 11:23:58 install insserv <none> 1.12.0-11
...

It appears that sysvinit depends on sysv-rc which depends on insserv. There appears to be a corresponding comment in the changelog:

  * Move the code to migrate to dependency based boot sequencing
    during upgrades from the insserv package to the sysv-rc package.
    Depend on insserv (>> 1.12.0-10) for this. Let initscripts depend
    on sysv-rc | file-rc to make sure they are installed first.
    Migration is a one-way process, enabled after a critical debconf
    question during upgrades when it is safe to do so (Closes:
    #540546, #541041, 541604). Checks previously done by
    update-bootsystem-insserv are now only done once in sysv-rc
    postinst (Closes: #538934). Dependency based boot sequencing is
    now the default. This change make it possible to remove both
    sysv-rc and insserv (Closes: #538959) if other packages want to
    take over the boot sequencing resposibility.