snmp - SNMP UCD dskTotalLow + dskTotalHigh

Question

I did snmpwalk of one of my linux box and the following is the output.

UCD-SNMP-MIB::dskTotalLow.1 = Gauge32: 276240608
UCD-SNMP-MIB::dskTotalLow.2 = Gauge32: 0
UCD-SNMP-MIB::dskTotalLow.3 = Gauge32: 0
UCD-SNMP-MIB::dskTotalLow.4 = Gauge32: 0
UCD-SNMP-MIB::dskTotalLow.5 = Gauge32: 74346640
UCD-SNMP-MIB::dskTotalLow.6 = Gauge32: 4031680
UCD-SNMP-MIB::dskTotalLow.7 = Gauge32: 1677158400
UCD-SNMP-MIB::dskTotalLow.8 = Gauge32: 1071652864
UCD-SNMP-MIB::dskTotalLow.9 = Gauge32: 0
UCD-SNMP-MIB::dskTotalLow.10 = Gauge32: 0
UCD-SNMP-MIB::dskTotalHigh.1 = Gauge32: 0
UCD-SNMP-MIB::dskTotalHigh.2 = Gauge32: 0
UCD-SNMP-MIB::dskTotalHigh.3 = Gauge32: 0
UCD-SNMP-MIB::dskTotalHigh.4 = Gauge32: 0
UCD-SNMP-MIB::dskTotalHigh.5 = Gauge32: 0
UCD-SNMP-MIB::dskTotalHigh.6 = Gauge32: 0
UCD-SNMP-MIB::dskTotalHigh.7 = Gauge32: 0
UCD-SNMP-MIB::dskTotalHigh.8 = Gauge32: 11
UCD-SNMP-MIB::dskTotalHigh.9 = Gauge32: 0
UCD-SNMP-MIB::dskTotalHigh.10 = Gauge32: 0

The disk index 8's total size is about 45Tb. In the UCD MIB documentation

dskTotalLow : "Total size of the disk/partion (kBytes). Together with dskTotalHigh composes 64-bit number."
dskTotalHigh: "Total size of the disk/partion (kBytes). Together with dskTotalLow composes 64-bit number."
How to get the total size from dskTotalLow and dskTotalHigh. Please help me in advance.

Thanks

Answer 1

For index 8, you get the high portion 0x0B (= 11), low portion 0x3FE0 2000 (= 1,071,652,864). So put them together we get 0x0B 3FE0 2000 (= 48,316,293,120). This matches 45-TB.

Or alternatively you can get the value by calculating

11 * 4,294,967,296 + 1,071,652,864 = 48,316,293,120

where 4,294,967,296 = 0x1 0000 0000