Unable to start sssd: Unable to open config database [/var/lib/sss/db/config.ldb]

Issue

• The SSSD service is failing with below error.

  [sssd] [ldb] (0x0020): Unable to open tdb '/var/lib/sss/db/config.ldb': Permission denied
  [sssd] [ldb] (0x0020): Failed to connect to '/var/lib/sss/db/config.ldb' with backend 'tdb': Unable to open tdb '/var/lib/sss/db/config.ldb': Permission denied
  [sssd] [confdb_init] (0x0010): Unable to open config database [/var/lib/sss/db/config.ldb]
  [sssd] [confdb_setup] (0x0010): The confdb initialization failed [5]: Input/output error
  [sssd] [load_configuration] (0x0010): Unable to setup ConfDB [5]: Input/output error
  [sssd] [main] (0x0010): SSSD couldn't load the configuration database.