Symptom
634 username vty0 exec Wed Apr 4 01:13:36.706 2018 GMT configure terminal
635 username vty0 config Wed Apr 4 01:13:43.328 2018 GMT interface TenGigE0/2/0/1
636 username vty0 config Wed Apr 4 01:13:50.952 2018 GMT no shutdown
637 username vty0 config Wed Apr 4 01:13:54.388 2018 GMT commit <<<<<<< Commit failed after some time
RP/0/RP0/CPU0:Router(config)#commit
System configuration operation in progress: node(s) initializing.
Please wait or use control-c to cancel this operation..................................................................................................................
RP/0/RP1/CPU0:Apr 4 00:13:26.444 : sysdb_shared_nc[422]: %SYSDB-SYSDB-7-INTERNAL : [12] : Resync Done for Consistency Chk Mismatch: path: ipc/ Act: 206, Stby: 207: rc 0x0 (No error)
.......
Commit operation cancelled by user.
639 username vty1 exec Wed Apr 4 01:26:04.744 2018 GMT configure terminal
640 username vty1 config Wed Apr 4 01:26:25.667 2018 GMT exit <<<< it has been locked
RP/0/RP0/CPU0:Router#conf t
Current Configuration Session Line User Date Lock
00000001-2bcc615f-00000000 vty0 username Wed Apr 4 01:13:36 2018 *
RP/0/RP0/CPU0:Router(config)#exit
641 username vty1 exec Wed Apr 4 01:26:36.146 2018 GMT configure exclusive <<<<< then you tried to lock it:
RP/0/RP0/CPU0:Router#conf e
Current Configuration Session Line User Date Lock
00000001-2bcc615f-00000000 vty0 username Wed Apr 4 01:13:36 2018 *
Workaround
clear configuration lock namespace