Riasanovsky's History of Russia says people (gentry and serfs alike) were drafted into the Imperial army for 25 year terms.
I noticed that the chief commandants of Kamchatka seemed to serve terms of about five years (Koselev 1802-1807, Petrovskii 1807-1813, Rudakov 1813-1817). These seem to have been Majors-General (rank IV).
I want to know how long subordinate officers would have served. Did all officers get shorter terms and soldiers longer ones, or did some other rules affect the terms of army service?