While grepping logs, I came across this crash, which I caused while adding many indices in a test environment. I don't know that there's any reason to believe one way or the other if this is specific to running on pg11b1.
< 2018-06-17 11:38:45.465 CDT pryzbyj >FATAL: the database system is in recovery mode < 2018-06-17 11:38:45.466 CDT pryzbyj >FATAL: the database system is in recovery mode < 2018-06-17 11:38:45.468 CDT >FATAL: could not extend file "base/17379/38665798": No space left on device < 2018-06-17 11:38:45.468 CDT >HINT: Check free disk space. < 2018-06-17 11:38:45.468 CDT >CONTEXT: WAL redo at 2AA/239676B8 for Heap/INSERT+INIT: off 1 < 2018-06-17 11:38:45.468 CDT >WARNING: buffer refcount leak: [2366] (rel=base/17379/38665798, blockNum=1241, flags=0x8a000000, refcount=1 1) TRAP: FailedAssertion("!(RefCountErrors == 0)", File: "bufmgr.c", Line: 2523) Unfortunately, I have neither a core nor stacktrace to share, as the DB was (until after running out of space) on the same FS as /var :( Jun 17 11:38:42 localhost abrt[30526]: Aborting dump: only 30MiB is available on /var/spool/abrt Jun 17 11:38:45 localhost abrt[1261]: Aborting dump: only 16MiB is available on /var/spool/abrt Not sure how useful it's to crash test ENOSPC (although I see there's continuing patches for this case). Justin