Thanks for the reply.
I'm not sure how to tell exactly what it is doing. I am running a script to log events but it gives no clue that I can interpret. Changing to <ALT F2> console the last line of the script as shown by 'tail' is
squeeze/main xkb-data 1.8-2 [839kB]'
Periodically, fairly early in this process I would be shown error messages of the form
'No path for 046d/c05a at 002/126'
I observed 8 distinct messages wherein all that changed was the 002/126 to 002/102 and then 002/052, 002/117. 002/080, 002/097, 002/038, 002/081. There were hours between messages. I determined that the 046d/c05a referred to my Logitech M100 mouse so I disconnected it from the system USB port. The system seemed to speed up for a time but has since reverted to slow. I judge speed by the frequency of the hard drive light flashes. The error messages stopped.