In an Advanced Availability configuration of CA SDM, Background server's stdlog files get rolled over to new files before reaching their default file size limit of 3MB.
first line of each stdlog has an entry like this before rest of the file gets populated.
05/16 06:22:57.29 BGHostname rep_daemon ==========> Was unable to write the last 3 messages. Last reason was: Permission denied (13)
05/15 16:05:23.14 BGHostname rep_daemon ==========> Was unable to write the last 3 messages. Last reason was: Permission denied (13)
CA SDM 17.1 in an Advanced Availability configuration. SDM Repositories were configured using UNC credentials.
1) Ensure the UNC credential information provided on each CA SDM Repository, is a valid account on the UNC server hosting the repository file share. This cannot be a local Windows user, but a Domain user
2) Explicitly add Full Security Permissions to the above user to NX_ROOT/log and NX_ROOT/bopcfg/CATALINA_BASE/temp folders so that the user is able to add/delete/modify files in these two folders