前回のrsyslog導入（【ProxmoxVE】rsyslogの導入と設定）に続き、snmpdの導入をしてみようと思います。
前提
rsyslogと同じですが、ProxmoxVEバージョンは8.2-1、非インターネット環境を想定して、apt-get以外の方法で導入してみます。
環境
以下のような環境にて試しています。
監視ソフトとしてZabbixを利用しました。
debパッケージの入手
snmpdの導入にあたり、下記パッケージをダウンロードし、Proxmoxへscpで配置しました。
・libc6_2.36-9+deb12u8_amd64.deb
・lsb-base_11.6_all.deb
・libsnmp-base_5.9.3+dfsg-2_all.deb
・libsensors-config_3.6.0-7.1_all.deb
・libssl3_3.0.14-1~deb12u2_amd64.deb
・libsensors5_3.6.0-7.1_amd64.deb
・libsnmp40_5.9.3+dfsg-2_amd64.deb
・snmpd_5.9.3+dfsg-2_amd64.deb
依存関係やバージョンの調べ方は以前の記事（【ProxmoxVE】apt-get出来ない環境での追加パッケージ確認方法）を参考にどうぞ。
パッケージのインストール
dpkg -iにて一つずつ導入しました。
インストール順は上で書いたパッケージの順序です。
dpkg -iでのsnmpd導入・コマンドと結果
root@pve103:/var/tmp/20240910_install_snmpd# dpkg -i libc6_2.36-9+deb12u8_amd64.deb
(Reading database ... 47863 files and directories currently installed.)
Preparing to unpack libc6_2.36-9+deb12u8_amd64.deb ...
Unpacking libc6:amd64 (2.36-9+deb12u8) over (2.36-9+deb12u6) ...
Setting up libc6:amd64 (2.36-9+deb12u8) ...
Processing triggers for libc-bin (2.36-9+deb12u6) ...
root@pve103:/var/tmp/20240910_install_snmpd#
root@pve103:/var/tmp/20240910_install_snmpd# dpkg -i lsb-base_11.6_all.deb
Selecting previously unselected package lsb-base.
(Reading database ... 47863 files and directories currently installed.)
Preparing to unpack lsb-base_11.6_all.deb ...
Unpacking lsb-base (11.6) ...
Setting up lsb-base (11.6) ...
root@pve103:/var/tmp/20240910_install_snmpd#
root@pve103:/var/tmp/20240910_install_snmpd# dpkg -i libsnmp-base_5.9.3+dfsg-2_all.deb
Selecting previously unselected package libsnmp-base.
(Reading database ... 47867 files and directories currently installed.)
Preparing to unpack libsnmp-base_5.9.3+dfsg-2_all.deb ...
Unpacking libsnmp-base (5.9.3+dfsg-2) ...
Setting up libsnmp-base (5.9.3+dfsg-2) ...
Processing triggers for man-db (2.11.2-2) ...
root@pve103:/var/tmp/20240910_install_snmpd#
root@pve103:/var/tmp/20240910_install_snmpd# dpkg -i libsensors-config_3.6.0-7.1_all.deb
Selecting previously unselected package libsensors-config.
(Reading database ... 47969 files and directories currently installed.)
Preparing to unpack libsensors-config_3.6.0-7.1_all.deb ...
Unpacking libsensors-config (1:3.6.0-7.1) ...
Setting up libsensors-config (1:3.6.0-7.1) ...
root@pve103:/var/tmp/20240910_install_snmpd#
root@pve103:/var/tmp/20240910_install_snmpd# dpkg -i libssl3_3.0.14-1~deb12u2_amd64.deb
(Reading database ... 47976 files and directories currently installed.)
Preparing to unpack libssl3_3.0.14-1~deb12u2_amd64.deb ...
Unpacking libssl3:amd64 (3.0.14-1~deb12u2) over (3.0.11-1~deb12u2) ...
Setting up libssl3:amd64 (3.0.14-1~deb12u2) ...
Processing triggers for libc-bin (2.36-9+deb12u6) ...
root@pve103:/var/tmp/20240910_install_snmpd#
root@pve103:/var/tmp/20240910_install_snmpd# dpkg -i libsensors5_3.6.0-7.1_amd64.deb
Selecting previously unselected package libsensors5:amd64.
(Reading database ... 48000 files and directories currently installed.)
Preparing to unpack libsensors5_3.6.0-7.1_amd64.deb ...
Unpacking libsensors5:amd64 (1:3.6.0-7.1) ...
Setting up libsensors5:amd64 (1:3.6.0-7.1) ...
Processing triggers for libc-bin (2.36-9+deb12u6) ...
root@pve103:/var/tmp/20240910_install_snmpd#
root@pve103:/var/tmp/20240910_install_snmpd# dpkg -i libsnmp40_5.9.3+dfsg-2_amd64.deb
(Reading database ... 48007 files and directories currently installed.)
Preparing to unpack libsnmp40_5.9.3+dfsg-2_amd64.deb ...
Unpacking libsnmp40:amd64 (5.9.3+dfsg-2) over (5.9.3+dfsg-2) ...
Setting up libsnmp40:amd64 (5.9.3+dfsg-2) ...
Processing triggers for libc-bin (2.36-9+deb12u6) ...
root@pve103:/var/tmp/20240910_install_snmpd#
root@pve103:/var/tmp/20240910_install_snmpd# dpkg -i snmpd_5.9.3+dfsg-2_amd64.deb
Selecting previously unselected package snmpd.
(Reading database ... 48007 files and directories currently installed.)
Preparing to unpack snmpd_5.9.3+dfsg-2_amd64.deb ...
Unpacking snmpd (5.9.3+dfsg-2) ...
Setting up snmpd (5.9.3+dfsg-2) ...
adduser: Warning: The home directory `/var/lib/snmp' does not belong to the user you are currently creating.
chown: warning: '.' should be ':': ‘Debian-snmp.Debian-snmp’
Created symlink /etc/systemd/system/multi-user.target.wants/snmpd.service → /lib/systemd/system/snmpd.service.
Processing triggers for man-db (2.11.2-2) ...
root@pve103:/var/tmp/20240910_install_snmpd#
snmpエージェント設定
/etc/snmp/snmpd.confファイルの以下を修正し、snmpdサービスの再起動（systemctl restart snmpd）を実施。
・「agentaddress 127.0.0.1,[::1]」を「agentaddress udp:161」に修正
・「view systemonly included ～～」を「view systemonly included .1」に修正
・コミュニティ名を修正
修正したsnmpd.conf全量
root@pve103:~# cat /etc/snmp/snmpd.conf
###########################################################################
#
# snmpd.conf
# An example configuration file for configuring the Net-SNMP agent ('snmpd')
# See snmpd.conf(5) man page for details
#
###########################################################################
# SECTION: System Information Setup
#
# syslocation: The [typically physical] location of the system.
# Note that setting this value here means that when trying to
# perform an snmp SET operation to the sysLocation.0 variable will make
# the agent return the "notWritable" error code. IE, including
# this token in the snmpd.conf file will disable write access to
# the variable.
# arguments: location_string
sysLocation Sitting on the Dock of the Bay
sysContact Me <me@example.org>
# sysservices: The proper value for the sysServices object.
# arguments: sysservices_number
sysServices 72
###########################################################################
# SECTION: Agent Operating Mode
#
# This section defines how the agent will operate when it
# is running.
# master: Should the agent operate as a master agent or not.
# Currently, the only supported master agent type for this token
# is "agentx".
#
# arguments: (on|yes|agentx|all|off|no)
master agentx
# agentaddress: The IP address and port number that the agent will listen on.
# By default the agent listens to any and all traffic from any
# interface on the default SNMP port (161). This allows you to
# specify which address, interface, transport type and port(s) that you
# want the agent to listen on. Multiple definitions of this token
# are concatenated together (using ':'s).
# arguments: [transport:]port[@interface/address],...
#agentaddress 127.0.0.1,[::1]
agentaddress udp:161
###########################################################################
# SECTION: Access Control Setup
#
# This section defines who is allowed to talk to your running
# snmp agent.
# Views
# arguments viewname included [oid]
# system + hrSystem groups only
#view systemonly included .1.3.6.1.2.1.1
#view systemonly included .1.3.6.1.2.1.25.1
view systemonly included .1
# rocommunity: a SNMPv1/SNMPv2c read-only access community name
# arguments: community [default|hostname|network/bits] [oid | -V view]
# Read-only access to everyone to the systemonly view
#rocommunity public default -V systemonly
#rocommunity6 public default -V systemonly
rocommunity <コミュニティ名> default -V systemonly
rocommunity6 <コミュニティ名> default -V systemonly
# SNMPv3 doesn't use communities, but users with (optionally) an
# authentication and encryption string. This user needs to be created
# with what they can view with rouser/rwuser lines in this file.
#
# createUser username (MD5|SHA|SHA-512|SHA-384|SHA-256|SHA-224) authpassphrase [DES|AES] [privpassphrase]
# e.g.
# createuser authPrivUser SHA-512 myauthphrase AES myprivphrase
#
# This should be put into /var/lib/snmp/snmpd.conf
#
# rouser: a SNMPv3 read-only access username
# arguments: username [noauth|auth|priv [OID | -V VIEW [CONTEXT]]]
rouser authPrivUser authpriv -V systemonly
# include a all *.conf files in a directory
includeDir /etc/snmp/snmpd.conf.d
root@pve103:~#
これで監視マネージャ側のSNMP監視設定を行えば、とりあえずCPU/メモリ/NWなどの情報収集が可能になりました。
ただし、ルートパーティションのディスク使用率については注意が必要そうです。
ルートパーティションのディスク使用率監視の注意点
Zabbix側で計算したディスク使用率と、dfコマンドで出力される使用率が一致しません。
dfコマンドの結果をよく見ると、「Size > Used + Avail」という状態になっており、snmpで取得できる総容量（HOST-RESOURCES-MIB::hrStorageSize）と使用量（HOST-RESOURCES-MIB::hrStorageUsed）で計算した場合に使用率が低くなってしまうようです。
以下は検証環境でのdf -h結果ですが、SizeとUsed、SizeとAvailどちらで計算しても、Use％の値と一致しませんでした。Used/Sizeが一番低く、次にUse％、Avail/Sizeが大きくなりましたので、より安全に運用するという観点ではSNMPでの監視ではなく、別途スクリプトなどを用意してAvail/Sizeを監視するのが良さそうです。（dfのUse%と一致しないので混乱するかもしれませんが・・・）
root@pve103:~# df -h
Filesystem Size Used Avail Use% Mounted on
udev 3.9G 0 3.9G 0% /dev
tmpfs 795M 876K 794M 1% /run
/dev/mapper/pve-root 19G 3.2G 15G 19% /
tmpfs 3.9G 60M 3.9G 2% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
/dev/fuse 128M 36K 128M 1% /etc/pve
tmpfs 3.9G 28K 3.9G 1% /var/lib/ceph/osd/ceph-2
192.168.100.209:/mnt/nfs1/share 178G 2.6G 175G 2% /mnt/pve/nfs_datastore
192.168.100.209:/mnt/nfs1/iso 186G 12G 175G 6% /mnt/pve/nfs_iso
192.168.100.209:/mnt/nfs1/template 178G 2.7G 175G 2% /mnt/pve/nfs_template
tmpfs 795M 0 795M 0% /run/user/0
root@pve103:~#
またCephを利用している場合、Cephディスクの状態や使用量なんかもSNMPでは取得できないと思いますので、こちらも別途監視スクリプト等を用意することになると思います。