I have set up sssd authentication on a Ubuntu Xenial workstation, with the Lightdm windowing manager.

When the sssd service starts the sssd_be process is taking 100% CPU. I am not that concerned with this.

However I see that when I am using the windowing system the mouse 'goes away' and sometimes the keyboard too,

ie there is no mouse pointer and the keyboard does not respond.  This says to me that the OS is very busy doing things,

and does not have time to service interrupts from the keyboard/mouse.

Has anyone else seen this behaviour?

I increased  the nss stanza to have  enum_cache_timeout = 1200

Clearly this will not help with the first enumeration - but it does keep the data for longer in the cache.

Also when sssd first starts up it seems to look at every account in the local /etc/passwd file and request information about it.

We have several hundred locally defined users in the passwd file at the moment.

Is this expected behaviour?  I would have though that only if an account actually makes a login attempt or uses a service then the information would be collected from AD/IPA/LDAP   I may be wrong and I am sure I will learn something here.