在snmpd.conf中采用disk关键字来监控系统运行的进程，格式如下： disk PATH [MIN=100000]
PATH: mount path to the disk in question.
MIN: Disks with space below this value will have the Mib's errorFlag set.
Default value = 100000(100megs).
代理将监视指定文件系统，并判断其可用总磁盘空间是否小于minumum,默认的minumum为100Mb minumum值可是设置为百分比，例如30%.
配置示例： 在配置文件中添加：www.it165.net disk / 10000000 #监控/，预设最小可用空间为10G； disk /boot 30% #监控/boot，预设最小可用空间为30%； disk /dev/shm #监控/dev/shm，不预设最小可用空间； （注：只是监控mount点，不是目录，可以用df查看mount点） MIB包含df命令所包含的所有信息 具体的OID为： root(.)->iso(1)->org(3)->dod(6)->internet(1)->private(4)->enterprises(1)->ucdavis(2021)->9 也就是：.1.3.6.1.4.1.2021.9
snmpwalk -v2c -cpublic 192.168.1.21 1.3.6.1.4.1.2021.9
UCD-SNMP-MIB::dskIndex.1 = INTEGER: 1 #监控的mount点索引ID
UCD-SNMP-MIB::dskIndex.2 = INTEGER: 2
UCD-SNMP-MIB::dskIndex.3 = INTEGER: 3
UCD-SNMP-MIB::dskPath.1 = STRING: / #监控的mount点
UCD-SNMP-MIB::dskPath.2 = STRING: /boot
UCD-SNMP-MIB::dskPath.3 = STRING: /dev/shm
UCD-SNMP-MIB::dskDevice.1 = STRING: /dev/mapper/vg_centos60a-lv_root #监控mount点的文件系统
UCD-SNMP-MIB::dskDevice.2 = STRING: /dev/sda1
UCD-SNMP-MIB::dskDevice.3 = STRING: tmpfs
UCD-SNMP-MIB::dskMinimum.1 = INTEGER: 10000000 #预设的最少可空间值，如没有设置默认为100M,如设置的为百分比，则为-1;
UCD-SNMP-MIB::dskMinimum.2 = INTEGER: -1
UCD-SNMP-MIB::dskMinimum.3 = INTEGER: 100000
UCD-SNMP-MIB::dskMinPercent.1 = INTEGER: -1 #预设的最少可空间值，如设置的为实际值，则为-1;
UCD-SNMP-MIB::dskMinPercent.2 = INTEGER: 30
UCD-SNMP-MIB::dskMinPercent.3 = INTEGER: -1
UCD-SNMP-MIB::dskTotal.1 = INTEGER: 10845100 #总空间
UCD-SNMP-MIB::dskTotal.2 = INTEGER: 495844
UCD-SNMP-MIB::dskTotal.3 = INTEGER: 255784
UCD-SNMP-MIB::dskAvail.1 = INTEGER: 9581368 #可用空间
UCD-SNMP-MIB::dskAvail.2 = INTEGER: 442608
UCD-SNMP-MIB::dskAvail.3 = INTEGER: 255784
UCD-SNMP-MIB::dskUsed.1 = INTEGER: 712820 #已用空间
UCD-SNMP-MIB::dskUsed.2 = INTEGER: 27636
UCD-SNMP-MIB::dskUsed.3 = INTEGER: 0
UCD-SNMP-MIB::dskPercent.1 = INTEGER: 7 #已用空间百分比
UCD-SNMP-MIB::dskPercent.2 = INTEGER: 6
UCD-SNMP-MIB::dskPercent.3 = INTEGER: 0
UCD-SNMP-MIB::dskPercentNode.1 = INTEGER: 3 #node已用百分比
UCD-SNMP-MIB::dskPercentNode.2 = INTEGER: 0
UCD-SNMP-MIB::dskPercentNode.3 = INTEGER: 0
UCD-SNMP-MIB::dskTotalLow.1 = Gauge32: 10845100 #可设置可用空间预设值（与dskTotal相当，但不一定完全相等）
UCD-SNMP-MIB::dskTotalLow.2 = Gauge32: 495844
UCD-SNMP-MIB::dskTotalLow.3 = Gauge32: 255784
UCD-SNMP-MIB::dskTotalHigh.1 = Gauge32: 0
UCD-SNMP-MIB::dskTotalHigh.2 = Gauge32: 0
UCD-SNMP-MIB::dskTotalHigh.3 = Gauge32: 0
UCD-SNMP-MIB::dskAvailLow.1 = Gauge32: 9581368 #还可分配空间（与dskAvail相当，但不一定完全相等）
UCD-SNMP-MIB::dskAvailLow.2 = Gauge32: 442608
UCD-SNMP-MIB::dskAvailLow.3 = Gauge32: 255784
UCD-SNMP-MIB::dskAvailHigh.1 = Gauge32: 0
UCD-SNMP-MIB::dskAvailHigh.2 = Gauge32: 0
UCD-SNMP-MIB::dskAvailHigh.3 = Gauge32: 0
UCD-SNMP-MIB::dskUsedLow.1 = Gauge32: 712820 #已用分配空间（与dskUsed相当，但不一定完全相等）
UCD-SNMP-MIB::dskUsedLow.2 = Gauge32: 27636
UCD-SNMP-MIB::dskUsedLow.3 = Gauge32: 0
UCD-SNMP-MIB::dskUsedHigh.1 = Gauge32: 0
UCD-SNMP-MIB::dskUsedHigh.2 = Gauge32: 0
UCD-SNMP-MIB::dskUsedHigh.3 = Gauge32: 0
UCD-SNMP-MIB::dskErrorFlag.1 = INTEGER: error(1) //是否超出了预设范围
UCD-SNMP-MIB::dskErrorFlag.2 = INTEGER: noError(0)
UCD-SNMP-MIB::dskErrorFlag.3 = INTEGER: noError(0)
UCD-SNMP-MIB::dskErrorMsg.1 = STRING: /: less than 10000000 free (= 9581368) //出错信息
UCD-SNMP-MIB::dskErrorMsg.2 = STRING:
UCD-SNMP-MIB::dskErrorMsg.3 = STRING:
