I got the same Error again after updating from 2.0.0p1.cre to 2.0.0p3.cre
2021-05-05 10:14:28 - Updating site 'monitor1' from version 2.0.0p1.cre to 2.0.0p3.cre...
* Updated etc/ssl/misc/tsget.pl
Creating temporary filesystem /omd/sites/monitor1/tmp...OK
Executing update-pre-hooks script "02_cmk-update-config"...
-| Initializing application...
-| Loading GUI plugins...
-| Updating Checkmk configuration...
-| ATTENTION: Some steps may take a long time depending on your installation, e.g. during major upgrades.
-| 1/15 Migrate deprecated network topology dashlet...
-| 2/15 Update global settings...
-| Replacing use_inline_snmp with snmp_backend_default
-| 3/15 Rewriting WATO tags...
-| 4/15 Rewriting WATO hosts and folders...
-| 5/15 Rewriting WATO rulesets...
-| Replacing ruleset non_inline_snmp_hosts with snmp_backend_hosts
-| 6/15 Rewriting autochecks...
-| 7/15 Cleanup version specific caches...
-| 8/15 Migrating fs_used name...
-| + "Migrating fs_used name" failed
-| Traceback (most recent call last):
-| File "/omd/sites/monitor1/lib/python3/cmk/update_config.py", line 146, in run
-| step_func()
-| File "/omd/sites/monitor1/lib/python3/cmk/update_config.py", line 183, in _update_fs_used_name
-| cmk.update_rrd_fs_names.update()
-| File "/omd/sites/monitor1/lib/python3/cmk/update_rrd_fs_names.py", line 186, in update
-| update_service_info(config_cache, get_hostnames(config_cache))
-| File "/omd/sites/monitor1/lib/python3/cmk/update_rrd_fs_names.py", line 174, in update_service_info
-| update_files(hostname, service.description, service.item, 'cmc')
-| File "/omd/sites/monitor1/lib/python3/cmk/update_rrd_fs_names.py", line 80, in update_files
-| filepath = get_info_file(hostname, servicedesc, source)
-| File "/omd/sites/monitor1/lib/python3/cmk/update_rrd_fs_names.py", line 64, in get_info_file
-| host_dir = cmk.base.cee.rrd.rrd_cmc_host_dir(hostname)
-| AttributeError: module 'cmk.base.cee' has no attribute 'rrd'
-| 9/15 Migrate pagetype topics...
-| 10/15 Migrate LDAP connections...
-| 11/15 Rewrite BI Configuration...
-| Skipping conversion of bi.mk (already done)
-| 12/15 Set version specific user attributes...
-| 13/15 Rewriting inventory data...
-| Skipping py2 inventory data update (already done)
-| 14/15 Migrate audit log...
-| No audit log present. Skipping.
-| 15/15 Rename discovered host label files...
-| Done
OK
Executing update-pre-hooks script "01_mkp-disable-outdated"...OK
Updating core configuration...
Generating configuration for core (type nagios)...Precompiling host checks...OK
OK
Finished update.
when updating from 1.6.0p22 to 2.0.0p1 the error did not appear.