diff --git a/src/bin/pg_verify_checksums/pg_verify_checksums.c b/src/bin/pg_verify_checksums/pg_verify_checksums.c
index 28c975446e..3eaa72ab31 100644
--- a/src/bin/pg_verify_checksums/pg_verify_checksums.c
+++ b/src/bin/pg_verify_checksums/pg_verify_checksums.c
@@ -1,7 +1,7 @@
 /*
  * pg_verify_checksums
  *
- * Verifies page level checksums in an offline cluster
+ * Verifies page level checksums in a cluster
  *
  *	Copyright (c) 2010-2018, PostgreSQL Global Development Group
  *
@@ -38,7 +38,7 @@ static const char *progname;
 static void
 usage()
 {
-	printf(_("%s verifies page level checksums in offline PostgreSQL database cluster.\n\n"), progname);
+	printf(_("%s verifies page level checksums in PostgreSQL database cluster.\n\n"), progname);
 	printf(_("Usage:\n"));
 	printf(_("  %s [OPTION] [DATADIR]\n"), progname);
 	printf(_("\nOptions:\n"));
@@ -57,6 +57,7 @@ static const char *skip[] = {
 	"pg_filenode.map",
 	"pg_internal.init",
 	"PG_VERSION",
+	"pgsql_tmp",
 	NULL,
 };
 
@@ -82,6 +83,7 @@ scan_file(char *fn, int segmentno)
 	PageHeader	header = (PageHeader) buf;
 	int			f;
 	int			blockno;
+	bool		block_retry = false;
 
 	f = open(fn, 0);
 	if (f < 0)
@@ -115,14 +117,56 @@ scan_file(char *fn, int segmentno)
 		csum = pg_checksum_page(buf, blockno + segmentno * RELSEG_SIZE);
 		if (csum != header->pd_checksum)
 		{
+			/*
+			 * Retry the block on the first failure.  It's
+			 * possible that we read the first 4K page of
+			 * the block just before postgres updated the
+			 * entire block so it ends up looking torn to
+			 * us. If there were less than 10 bad blocks so
+			 * far, we wait for 500ms before we retry.
+			 */
+			if (block_retry == false)
+			{
+				if (badblocks < 10)
+					pg_usleep(500);
+
+				/* Seek to the beginning of the failed block */
+				if (lseek(f, -BLCKSZ, SEEK_CUR) == -1)
+				{
+					fprintf(stderr, _("%s: could not lseek in file \"%s\": %m\n"),
+							progname, fn);
+					exit(1);
+				}
+
+				/* Set flag so we know a retry was attempted */
+				block_retry = true;
+
+				if (debug)
+					fprintf(stderr, _("%s: checksum verification failed on first attempt in file \"%s\", block %d: calculated checksum %X but expected %X\n"),
+							progname, fn, blockno, csum, header->pd_checksum);
+
+				/* Reset loop to validate the block again */
+				blockno--;
+
+				continue;
+			}
+
 			if (ControlFile->data_checksum_version == PG_DATA_CHECKSUM_VERSION)
 				fprintf(stderr, _("%s: checksum verification failed in file \"%s\", block %d: calculated checksum %X but expected %X\n"),
 						progname, fn, blockno, csum, header->pd_checksum);
 			badblocks++;
 		}
 		else if (debug)
-			fprintf(stderr, _("%s: checksum verified in file \"%s\", block %d: %X\n"),
-					progname, fn, blockno, csum);
+		{
+			if (block_retry)
+				fprintf(stderr, _("%s: block %d in file \"%s\" verified ok on recheck\n"),
+						progname, blockno, fn);
+			else
+				fprintf(stderr, _("%s: checksum verified in file \"%s\", block %d: %X\n"),
+						progname, fn, blockno, csum);
+		}
+
+		block_retry = false;
 	}
 
 	close(f);
@@ -154,6 +198,15 @@ scan_directory(char *basedir, char *subdir)
 		snprintf(fn, sizeof(fn), "%s/%s", path, de->d_name);
 		if (lstat(fn, &st) < 0)
 		{
+			if (errno == ENOENT)
+			{
+				/* File was removed in the meantime */
+				if (debug)
+					fprintf(stderr, _("%s: ignoring deleted file \"%s\"\n"),
+							progname, fn);
+				continue;
+			}
+
 			fprintf(stderr, _("%s: could not stat file \"%s\": %s\n"),
 					progname, fn, strerror(errno));
 			exit(1);
@@ -284,7 +337,7 @@ main(int argc, char *argv[])
 		exit(1);
 	}
 
-	/* Check if cluster is running */
+	/* Check if checksums are enabled */
 	ControlFile = get_controlfile(DataDir, progname, &crc_ok);
 	if (!crc_ok)
 	{
@@ -292,13 +345,6 @@ main(int argc, char *argv[])
 		exit(1);
 	}
 
-	if (ControlFile->state != DB_SHUTDOWNED &&
-		ControlFile->state != DB_SHUTDOWNED_IN_RECOVERY)
-	{
-		fprintf(stderr, _("%s: cluster must be shut down to verify checksums.\n"), progname);
-		exit(1);
-	}
-
 	if (ControlFile->data_checksum_version == 0)
 	{
 		fprintf(stderr, _("%s: data checksums are not enabled in cluster.\n"), progname);