http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=475158
snmpd: keeps complaining on missing /proc/ stats inside vserver flooding syslog

diff -urNp -x '*.orig' net-snmp-5.9.org/agent/mibgroup/hardware/cpu/cpu_linux.c net-snmp-5.9/agent/mibgroup/hardware/cpu/cpu_linux.c
--- net-snmp-5.9.org/agent/mibgroup/hardware/cpu/cpu_linux.c	2020-08-14 23:41:47.000000000 +0200
+++ net-snmp-5.9/agent/mibgroup/hardware/cpu/cpu_linux.c	2021-02-28 14:29:33.661445570 +0100
@@ -309,7 +309,7 @@ void _cpu_load_swap_etc( char *buff, net
             cpu->pageOut = (unsigned long long)pout;
 	} else {
 	    if (first)
-		snmp_log(LOG_ERR, "No page line in %s\n", STAT_FILE);
+		snmp_log(LOG_INFO, "No page line in %s\n", STAT_FILE);
             cpu->pageIn  = cpu->pageOut = 0;
 	}
 	b = strstr(buff, "swap ");
@@ -319,7 +319,7 @@ void _cpu_load_swap_etc( char *buff, net
             cpu->swapOut = (unsigned long long)swpout;
 	} else {
 	    if (first)
-		snmp_log(LOG_ERR, "No swap line in %s\n", STAT_FILE);
+		snmp_log(LOG_INFO, "No swap line in %s\n", STAT_FILE);
             cpu->swapIn  = cpu->swapOut = 0;
 	}
     }
diff -urNp -x '*.orig' net-snmp-5.9.org/agent/mibgroup/ucd-snmp/diskio.c net-snmp-5.9/agent/mibgroup/ucd-snmp/diskio.c
--- net-snmp-5.9.org/agent/mibgroup/ucd-snmp/diskio.c	2020-08-14 23:41:47.000000000 +0200
+++ net-snmp-5.9/agent/mibgroup/ucd-snmp/diskio.c	2021-02-28 14:29:33.661445570 +0100
@@ -1367,7 +1367,8 @@ getstats(void)
     struct stat stbuf;
     FILE* parts;
     time_t now;
-    
+    static int first = 1;
+
     now = time(NULL);
     if (cache_time + CACHE_TIMEOUT > now) {
         return 0;
@@ -1423,7 +1424,11 @@ getstats(void)
 	int rc;
 	parts = fopen("/proc/partitions", "r");
 	if (!parts) {
-	    snmp_log_perror("/proc/partitions");
+	    if (first) {
+		// log error only once
+		snmp_log_perror("/proc/partitions");
+		first = 0;
+	    }
 	    return 1;
 	}
 
diff -urNp -x '*.orig' net-snmp-5.9.org/agent/mibgroup/ucd-snmp/vmstat_linux.c net-snmp-5.9/agent/mibgroup/ucd-snmp/vmstat_linux.c
--- net-snmp-5.9.org/agent/mibgroup/ucd-snmp/vmstat_linux.c	2020-08-14 23:41:47.000000000 +0200
+++ net-snmp-5.9/agent/mibgroup/ucd-snmp/vmstat_linux.c	2021-02-28 14:29:33.661445570 +0100
@@ -337,7 +337,7 @@ getstat(unsigned long *cuse, unsigned lo
 	    sscanf(b, "page %u %u", pin, pout);
 	else {
 	    if (first)
-		snmp_log(LOG_ERR, "No page line in %s\n", STAT_FILE);
+		snmp_log(LOG_INFO, "No page line in %s\n", STAT_FILE);
 	    *pin = *pout = 0;
 	}
 	b = strstr(buff, "swap ");
@@ -345,7 +345,7 @@ getstat(unsigned long *cuse, unsigned lo
 	    sscanf(b, "swap %u %u", swpin, swpout);
 	else {
 	    if (first)
-		snmp_log(LOG_ERR, "No swap line in %s\n", STAT_FILE);
+		snmp_log(LOG_INFO, "No swap line in %s\n", STAT_FILE);
 	    *swpin = *swpout = 0;
 	}
     }