[Sts-sponsors] [Bug 1835818] Re: snmpd causes autofs mount points to be mounted on service start/restart
sponsored for e,d,b,x -- You received this bug notification because you are a member of STS Sponsors, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1835818 Title: snmpd causes autofs mount points to be mounted on service start/restart Status in net-snmp package in Ubuntu: In Progress Status in net-snmp source package in Xenial: In Progress Status in net-snmp source package in Bionic: In Progress Status in net-snmp source package in Cosmic: Won't Fix Status in net-snmp source package in Disco: In Progress Status in net-snmp source package in Eoan: In Progress Status in net-snmp package in Debian: Unknown Bug description: [Impact] Autofs direct map triggers are visible in /etc/mtab. On boot, when snmpd starts, it iterates over the entries in /etc/mtab and performs statfs() on them. This trigger automount to mount autofs mounts even if the user does not explicitly access them. However this happens only if autofs service is started before snmpd. If snmpd stars first /etc/mtab is not yet populated with autofs mounts and therefore are not mounted. When there a few autofs mount points the impact is insignificant. However when there are thousands of them, this causes unnecessary overhead on operations such as df. This also delays the system shutdown time since everything needs to be unmounted. [Test Case] *** Test Case 1 - During boot: The user that brought this issue to our attention would observe all autofs mounts be mounted at boot, because in their environment autofs would start first. In my environment snmpd starts first so to reproduce I had to add a small delay in snmpd init script. In /etc/init.d/snmp : @@ -36,6 +36,8 @@ cd / case "$1" in start) +# Delay snmp start +sleep 2 log_daemon_msg "Starting SNMP services:" # remove old symlink with previous version if [ -L /var/run/agentx ]; then $cat /etc/auto.master /- /etc/auto.nfs --timeout=30 $cat /etc/auto.nfs /home/test1 -fstype=nfs,hard,intr,nosuid,no-subtree-check,tcp :/srv/export/test1 /home/test2 -fstype=nfs,hard,intr,nosuid,no-subtree-check,tcp :/srv/export/test2 Reboot vm, syslog entries : # Autofs starts Jul 11 11:04:16 xenial-vm3 autofs[1295]: * Starting automount... Jul 11 11:04:16 xenial-vm3 automount[1357]: Starting automounter version 5.1.1, master map /etc/auto.master Jul 11 11:04:16 xenial-vm3 automount[1357]: using kernel protocol version 5.02 # Mount triggers, now visible in mtab Jul 11 11:04:16 xenial-vm3 automount[1357]: mounted direct on /home/test1 with timeout 300, freq 75 seconds Jul 11 11:04:16 xenial-vm3 automount[1357]: mounted direct on /home/test2 with timeout 300, freq 75 seconds Jul 11 11:04:16 xenial-vm3 autofs[1295]:...done. ... # SNMP starts Jul 11 11:04:18 xenial-vm3 snmpd[1294]: * Starting SNMP services: Jul 11 11:04:18 xenial-vm3 systemd[1]: proc-sys-fs-binfmt_misc.automount: Got automount request for /proc/sys/fs/binfmt_misc, triggered by 1394 (snmpd) Jul 11 11:04:18 xenial-vm3 systemd[1]: Mounting Arbitrary Executable File Formats File System... Jul 11 11:04:18 xenial-vm3 systemd[1]: Mounted Arbitrary Executable File Formats File System. Jul 11 11:04:18 xenial-vm3 automount[1357]: attempting to mount entry /home/test1 <== Jul 11 11:04:18 xenial-vm3 kernel: [8.880685] FS-Cache: Loaded Jul 11 11:04:18 xenial-vm3 kernel: [8.889318] FS-Cache: Netfs 'nfs' registered for caching Jul 11 11:04:18 xenial-vm3 kernel: [8.902672] NFS: Registering the id_resolver key type Jul 11 11:04:18 xenial-vm3 kernel: [8.902680] Key type id_resolver registered Jul 11 11:04:18 xenial-vm3 kernel: [8.902682] Key type id_legacy registered Jul 11 11:04:18 xenial-vm3 automount[1357]: mounted /home/test1 <== Jul 11 11:04:18 xenial-vm3 automount[1357]: attempting to mount entry /home/test2 <== Jul 11 11:04:18 xenial-vm3 kernel: [9.163011] random: nonblocking pool is initialized Jul 11 11:04:18 xenial-vm3 automount[1357]: mounted /home/test2 <=== *** Test Case 2 - Restart snmpd : To reproduce this case, autofs mounts should not be mounted to begin with. (restart autofs or let it expire) #systemctl restart snmpd.service Syslog entries : Jul 11 11:15:40 xenial-vm3 systemd[1]: Stopping LSB: SNMP agents... Jul 11 11:15:40 xenial-vm3 snmpd[1668]: * Stopping SNMP services: Jul 11 11:15:40 xenial-vm3 snmpd[1434]: Received TERM or STOP signal... shutting down... Jul 11 11:15:40 xenial-vm3 systemd[1]: Stopped LSB: SNMP agents. Jul 11 11:15:40 xenial-vm3 systemd[1]: Starting LSB: SNMP agents... Jul 11 11:15:42 xenial-vm3 snmpd[1677]: * Starting SNMP services: Jul 11 11:15:42 xenial-vm3 automount[1357]: attempting to mount entry /home/test1 <=== Jul 11 11:15:42 xenial-vm3 automount[1357]: mounted /home/test1 <=== Jul 11 11:15:42
[Sts-sponsors] [Bug 1835818] Re: snmpd causes autofs mount points to be mounted on service start/restart
** Tags added: sts-sponsor sts-sponsor-ddstreet -- You received this bug notification because you are a member of STS Sponsors, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1835818 Title: snmpd causes autofs mount points to be mounted on service start/restart Status in net-snmp package in Ubuntu: In Progress Status in net-snmp source package in Xenial: In Progress Status in net-snmp source package in Bionic: In Progress Status in net-snmp source package in Cosmic: Won't Fix Status in net-snmp source package in Disco: In Progress Status in net-snmp source package in Eoan: In Progress Status in net-snmp package in Debian: Unknown Bug description: [Impact] Autofs direct map triggers are visible in /etc/mtab. On boot, when snmpd starts, it iterates over the entries in /etc/mtab and performs statfs() on them. This trigger automount to mount autofs mounts even if the user does not explicitly access them. However this happens only if autofs service is started before snmpd. If snmpd stars first /etc/mtab is not yet populated with autofs mounts and therefore are not mounted. When there a few autofs mount points the impact is insignificant. However when there are thousands of them, this causes unnecessary overhead on operations such as df. This also delays the system shutdown time since everything needs to be unmounted. [Test Case] *** Test Case 1 - During boot: The user that brought this issue to our attention would observe all autofs mounts be mounted at boot, because in their environment autofs would start first. In my environment snmpd starts first so to reproduce I had to add a small delay in snmpd init script. In /etc/init.d/snmp : @@ -36,6 +36,8 @@ cd / case "$1" in start) +# Delay snmp start +sleep 2 log_daemon_msg "Starting SNMP services:" # remove old symlink with previous version if [ -L /var/run/agentx ]; then $cat /etc/auto.master /- /etc/auto.nfs --timeout=30 $cat /etc/auto.nfs /home/test1 -fstype=nfs,hard,intr,nosuid,no-subtree-check,tcp :/srv/export/test1 /home/test2 -fstype=nfs,hard,intr,nosuid,no-subtree-check,tcp :/srv/export/test2 Reboot vm, syslog entries : # Autofs starts Jul 11 11:04:16 xenial-vm3 autofs[1295]: * Starting automount... Jul 11 11:04:16 xenial-vm3 automount[1357]: Starting automounter version 5.1.1, master map /etc/auto.master Jul 11 11:04:16 xenial-vm3 automount[1357]: using kernel protocol version 5.02 # Mount triggers, now visible in mtab Jul 11 11:04:16 xenial-vm3 automount[1357]: mounted direct on /home/test1 with timeout 300, freq 75 seconds Jul 11 11:04:16 xenial-vm3 automount[1357]: mounted direct on /home/test2 with timeout 300, freq 75 seconds Jul 11 11:04:16 xenial-vm3 autofs[1295]:...done. ... # SNMP starts Jul 11 11:04:18 xenial-vm3 snmpd[1294]: * Starting SNMP services: Jul 11 11:04:18 xenial-vm3 systemd[1]: proc-sys-fs-binfmt_misc.automount: Got automount request for /proc/sys/fs/binfmt_misc, triggered by 1394 (snmpd) Jul 11 11:04:18 xenial-vm3 systemd[1]: Mounting Arbitrary Executable File Formats File System... Jul 11 11:04:18 xenial-vm3 systemd[1]: Mounted Arbitrary Executable File Formats File System. Jul 11 11:04:18 xenial-vm3 automount[1357]: attempting to mount entry /home/test1 <== Jul 11 11:04:18 xenial-vm3 kernel: [8.880685] FS-Cache: Loaded Jul 11 11:04:18 xenial-vm3 kernel: [8.889318] FS-Cache: Netfs 'nfs' registered for caching Jul 11 11:04:18 xenial-vm3 kernel: [8.902672] NFS: Registering the id_resolver key type Jul 11 11:04:18 xenial-vm3 kernel: [8.902680] Key type id_resolver registered Jul 11 11:04:18 xenial-vm3 kernel: [8.902682] Key type id_legacy registered Jul 11 11:04:18 xenial-vm3 automount[1357]: mounted /home/test1 <== Jul 11 11:04:18 xenial-vm3 automount[1357]: attempting to mount entry /home/test2 <== Jul 11 11:04:18 xenial-vm3 kernel: [9.163011] random: nonblocking pool is initialized Jul 11 11:04:18 xenial-vm3 automount[1357]: mounted /home/test2 <=== *** Test Case 2 - Restart snmpd : To reproduce this case, autofs mounts should not be mounted to begin with. (restart autofs or let it expire) #systemctl restart snmpd.service Syslog entries : Jul 11 11:15:40 xenial-vm3 systemd[1]: Stopping LSB: SNMP agents... Jul 11 11:15:40 xenial-vm3 snmpd[1668]: * Stopping SNMP services: Jul 11 11:15:40 xenial-vm3 snmpd[1434]: Received TERM or STOP signal... shutting down... Jul 11 11:15:40 xenial-vm3 systemd[1]: Stopped LSB: SNMP agents. Jul 11 11:15:40 xenial-vm3 systemd[1]: Starting LSB: SNMP agents... Jul 11 11:15:42 xenial-vm3 snmpd[1677]: * Starting SNMP services: Jul 11 11:15:42 xenial-vm3 automount[1357]: attempting to mount entry /home/test1 <=== Jul 11 11:15:42 xenial-vm3 automount[1357]: mounted /home/test1
[Sts-sponsors] [Bug 1835818] Re: snmpd causes autofs mount points to be mounted on service start/restart
** Bug watch added: Debian Bug tracker #935325 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=935325 ** Also affects: net-snmp (Debian) via https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=935325 Importance: Unknown Status: Unknown ** Description changed: [Impact] Autofs direct map triggers are visible in /etc/mtab. On boot, when snmpd starts, it iterates over the entries in /etc/mtab and performs statfs() on them. This trigger automount to mount autofs mounts even if the user does not explicitly access them. However this happens only if autofs service is started before snmpd. If snmpd stars first /etc/mtab is not yet populated with autofs mounts and therefore are not mounted. When there a few autofs mount points the impact is insignificant. However when there are thousands of them, this causes unnecessary overhead on operations such as df. This also delays the system shutdown time since everything needs to be unmounted. [Test Case] *** Test Case 1 - During boot: The user that brought this issue to our attention would observe all autofs mounts be mounted at boot, because in their environment autofs would start first. In my environment snmpd starts first so to reproduce I had to add a small delay in snmpd init script. In /etc/init.d/snmp : @@ -36,6 +36,8 @@ cd / case "$1" in start) +# Delay snmp start +sleep 2 log_daemon_msg "Starting SNMP services:" # remove old symlink with previous version if [ -L /var/run/agentx ]; then $cat /etc/auto.master /- /etc/auto.nfs --timeout=30 $cat /etc/auto.nfs /home/test1 -fstype=nfs,hard,intr,nosuid,no-subtree-check,tcp :/srv/export/test1 /home/test2 -fstype=nfs,hard,intr,nosuid,no-subtree-check,tcp :/srv/export/test2 Reboot vm, syslog entries : # Autofs starts Jul 11 11:04:16 xenial-vm3 autofs[1295]: * Starting automount... Jul 11 11:04:16 xenial-vm3 automount[1357]: Starting automounter version 5.1.1, master map /etc/auto.master Jul 11 11:04:16 xenial-vm3 automount[1357]: using kernel protocol version 5.02 # Mount triggers, now visible in mtab Jul 11 11:04:16 xenial-vm3 automount[1357]: mounted direct on /home/test1 with timeout 300, freq 75 seconds Jul 11 11:04:16 xenial-vm3 automount[1357]: mounted direct on /home/test2 with timeout 300, freq 75 seconds Jul 11 11:04:16 xenial-vm3 autofs[1295]:...done. ... # SNMP starts Jul 11 11:04:18 xenial-vm3 snmpd[1294]: * Starting SNMP services: Jul 11 11:04:18 xenial-vm3 systemd[1]: proc-sys-fs-binfmt_misc.automount: Got automount request for /proc/sys/fs/binfmt_misc, triggered by 1394 (snmpd) Jul 11 11:04:18 xenial-vm3 systemd[1]: Mounting Arbitrary Executable File Formats File System... Jul 11 11:04:18 xenial-vm3 systemd[1]: Mounted Arbitrary Executable File Formats File System. Jul 11 11:04:18 xenial-vm3 automount[1357]: attempting to mount entry /home/test1 <== Jul 11 11:04:18 xenial-vm3 kernel: [8.880685] FS-Cache: Loaded Jul 11 11:04:18 xenial-vm3 kernel: [8.889318] FS-Cache: Netfs 'nfs' registered for caching Jul 11 11:04:18 xenial-vm3 kernel: [8.902672] NFS: Registering the id_resolver key type Jul 11 11:04:18 xenial-vm3 kernel: [8.902680] Key type id_resolver registered Jul 11 11:04:18 xenial-vm3 kernel: [8.902682] Key type id_legacy registered Jul 11 11:04:18 xenial-vm3 automount[1357]: mounted /home/test1 <== Jul 11 11:04:18 xenial-vm3 automount[1357]: attempting to mount entry /home/test2 <== Jul 11 11:04:18 xenial-vm3 kernel: [9.163011] random: nonblocking pool is initialized Jul 11 11:04:18 xenial-vm3 automount[1357]: mounted /home/test2 <=== *** Test Case 2 - Restart snmpd : To reproduce this case, autofs mounts should not be mounted to begin with. (restart autofs or let it expire) #systemctl restart snmpd.service Syslog entries : Jul 11 11:15:40 xenial-vm3 systemd[1]: Stopping LSB: SNMP agents... Jul 11 11:15:40 xenial-vm3 snmpd[1668]: * Stopping SNMP services: Jul 11 11:15:40 xenial-vm3 snmpd[1434]: Received TERM or STOP signal... shutting down... Jul 11 11:15:40 xenial-vm3 systemd[1]: Stopped LSB: SNMP agents. Jul 11 11:15:40 xenial-vm3 systemd[1]: Starting LSB: SNMP agents... Jul 11 11:15:42 xenial-vm3 snmpd[1677]: * Starting SNMP services: Jul 11 11:15:42 xenial-vm3 automount[1357]: attempting to mount entry /home/test1 <=== Jul 11 11:15:42 xenial-vm3 automount[1357]: mounted /home/test1 <=== Jul 11 11:15:42 xenial-vm3 automount[1357]: attempting to mount entry /home/test2 <=== Jul 11 11:15:42 xenial-vm3 automount[1357]: mounted /home/test2 <=== Jul 11 11:15:42 xenial-vm3 snmpd[1684]: /etc/snmp/snmpd.conf: line 145: Warning: Unknown token: defaultMonitors. Jul 11 11:15:42 xenial-vm3 snmpd[1684]: /etc/snmp/snmpd.conf: line 147: Warning:
[Sts-sponsors] [Bug 1835818] Re: snmpd causes autofs mount points to be mounted on service start/restart
** Description changed: [Impact] Autofs direct map triggers are visible in /etc/mtab. On boot, when snmpd starts, it iterates over the entries in /etc/mtab and performs statfs() on them. This trigger automount to mount autofs mounts even if the user does not explicitly access them. However this happens only if autofs service is started before snmpd. If snmpd stars first /etc/mtab is not yet populated with autofs mounts and therefore are not mounted. When there a few autofs mount points the impact is insignificant. However when there are thousands of them, this causes unnecessary overhead on operations such as df. This also delays the system shutdown time since everything needs to be unmounted. [Test Case] *** Test Case 1 - During boot: The user that brought this issue to our attention would observe all autofs mounts be mounted at boot, because in their environment autofs would start first. In my environment snmpd starts first so to reproduce I had to add a small delay in snmpd init script. In /etc/init.d/snmp : @@ -36,6 +36,8 @@ cd / - - case "$1" in -start) + + case "$1" in + start) +# Delay snmp start +sleep 2 - log_daemon_msg "Starting SNMP services:" - # remove old symlink with previous version - if [ -L /var/run/agentx ]; then - + log_daemon_msg "Starting SNMP services:" + # remove old symlink with previous version + if [ -L /var/run/agentx ]; then $cat /etc/auto.master /- /etc/auto.nfs --timeout=30 $cat /etc/auto.nfs /home/test1 -fstype=nfs,hard,intr,nosuid,no-subtree-check,tcp :/srv/export/test1 /home/test2 -fstype=nfs,hard,intr,nosuid,no-subtree-check,tcp :/srv/export/test2 Reboot vm, syslog entries : # Autofs starts Jul 11 11:04:16 xenial-vm3 autofs[1295]: * Starting automount... Jul 11 11:04:16 xenial-vm3 automount[1357]: Starting automounter version 5.1.1, master map /etc/auto.master Jul 11 11:04:16 xenial-vm3 automount[1357]: using kernel protocol version 5.02 # Mount triggers, now visible in mtab Jul 11 11:04:16 xenial-vm3 automount[1357]: mounted direct on /home/test1 with timeout 300, freq 75 seconds Jul 11 11:04:16 xenial-vm3 automount[1357]: mounted direct on /home/test2 with timeout 300, freq 75 seconds Jul 11 11:04:16 xenial-vm3 autofs[1295]:...done. ... # SNMP starts Jul 11 11:04:18 xenial-vm3 snmpd[1294]: * Starting SNMP services: Jul 11 11:04:18 xenial-vm3 systemd[1]: proc-sys-fs-binfmt_misc.automount: Got automount request for /proc/sys/fs/binfmt_misc, triggered by 1394 (snmpd) Jul 11 11:04:18 xenial-vm3 systemd[1]: Mounting Arbitrary Executable File Formats File System... Jul 11 11:04:18 xenial-vm3 systemd[1]: Mounted Arbitrary Executable File Formats File System. Jul 11 11:04:18 xenial-vm3 automount[1357]: attempting to mount entry /home/test1 <== Jul 11 11:04:18 xenial-vm3 kernel: [8.880685] FS-Cache: Loaded Jul 11 11:04:18 xenial-vm3 kernel: [8.889318] FS-Cache: Netfs 'nfs' registered for caching Jul 11 11:04:18 xenial-vm3 kernel: [8.902672] NFS: Registering the id_resolver key type Jul 11 11:04:18 xenial-vm3 kernel: [8.902680] Key type id_resolver registered Jul 11 11:04:18 xenial-vm3 kernel: [8.902682] Key type id_legacy registered Jul 11 11:04:18 xenial-vm3 automount[1357]: mounted /home/test1 <== Jul 11 11:04:18 xenial-vm3 automount[1357]: attempting to mount entry /home/test2 <== Jul 11 11:04:18 xenial-vm3 kernel: [9.163011] random: nonblocking pool is initialized Jul 11 11:04:18 xenial-vm3 automount[1357]: mounted /home/test2 <=== - *** Test Case 2 - Restart snmpd : To reproduce this case, autofs mounts should not be mounted to begin with. (restart autofs or let it expire) #systemctl restart snmpd.service Syslog entries : Jul 11 11:15:40 xenial-vm3 systemd[1]: Stopping LSB: SNMP agents... Jul 11 11:15:40 xenial-vm3 snmpd[1668]: * Stopping SNMP services: Jul 11 11:15:40 xenial-vm3 snmpd[1434]: Received TERM or STOP signal... shutting down... Jul 11 11:15:40 xenial-vm3 systemd[1]: Stopped LSB: SNMP agents. Jul 11 11:15:40 xenial-vm3 systemd[1]: Starting LSB: SNMP agents... Jul 11 11:15:42 xenial-vm3 snmpd[1677]: * Starting SNMP services: Jul 11 11:15:42 xenial-vm3 automount[1357]: attempting to mount entry /home/test1 <=== Jul 11 11:15:42 xenial-vm3 automount[1357]: mounted /home/test1 <=== Jul 11 11:15:42 xenial-vm3 automount[1357]: attempting to mount entry /home/test2 <=== Jul 11 11:15:42 xenial-vm3 automount[1357]: mounted /home/test2 <=== Jul 11 11:15:42 xenial-vm3 snmpd[1684]: /etc/snmp/snmpd.conf: line 145: Warning: Unknown token: defaultMonitors. Jul 11 11:15:42 xenial-vm3 snmpd[1684]: /etc/snmp/snmpd.conf: line 147: Warning: Unknown token: linkUpDownNotifications. Jul 11 11:15:42 xenial-vm3 snmpd[1684]:
[Sts-sponsors] [Bug 1835818] Re: snmpd causes autofs mount points to be mounted on service start/restart
After discussion with slashd from the STS Sponsors team, I am unsubscribing this from Sponsors as STS Sponsors will handle this, and it does not need to be handled by the standard sponsors team. -- You received this bug notification because you are a member of STS Sponsors, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1835818 Title: snmpd causes autofs mount points to be mounted on service start/restart Status in net-snmp package in Ubuntu: In Progress Status in net-snmp source package in Xenial: In Progress Status in net-snmp source package in Bionic: In Progress Status in net-snmp source package in Cosmic: Won't Fix Status in net-snmp source package in Disco: In Progress Status in net-snmp source package in Eoan: In Progress Bug description: [Impact] Autofs direct map triggers are visible in /etc/mtab. On boot, when snmpd starts, it iterates over the entries in /etc/mtab and performs statfs() on them. This trigger automount to mount autofs mounts even if the user does not explicitly access them. However this happens only if autofs service is started before snmpd. If snmpd stars first /etc/mtab is not yet populated with autofs mounts and therefore are not mounted. When there a few autofs mount points the impact is insignificant. However when there are thousands of them, this causes unnecessary overhead on operations such as df. This also delays the system shutdown time since everything needs to be unmounted. [Test Case] *** Test Case 1 - During boot: The user that brought this issue to our attention would observe all autofs mounts be mounted at boot, because in their environment autofs would start first. In my environment snmpd starts first so to reproduce I had to add a small delay in snmpd init script. In /etc/init.d/snmp : @@ -36,6 +36,8 @@ cd / case "$1" in start) +# Delay snmp start +sleep 2 log_daemon_msg "Starting SNMP services:" # remove old symlink with previous version if [ -L /var/run/agentx ]; then $cat /etc/auto.master /- /etc/auto.nfs --timeout=30 $cat /etc/auto.nfs /home/test1 -fstype=nfs,hard,intr,nosuid,no-subtree-check,tcp :/srv/export/test1 /home/test2 -fstype=nfs,hard,intr,nosuid,no-subtree-check,tcp :/srv/export/test2 Reboot vm, syslog entries : # Autofs starts Jul 11 11:04:16 xenial-vm3 autofs[1295]: * Starting automount... Jul 11 11:04:16 xenial-vm3 automount[1357]: Starting automounter version 5.1.1, master map /etc/auto.master Jul 11 11:04:16 xenial-vm3 automount[1357]: using kernel protocol version 5.02 # Mount triggers, now visible in mtab Jul 11 11:04:16 xenial-vm3 automount[1357]: mounted direct on /home/test1 with timeout 300, freq 75 seconds Jul 11 11:04:16 xenial-vm3 automount[1357]: mounted direct on /home/test2 with timeout 300, freq 75 seconds Jul 11 11:04:16 xenial-vm3 autofs[1295]:...done. ... # SNMP starts Jul 11 11:04:18 xenial-vm3 snmpd[1294]: * Starting SNMP services: Jul 11 11:04:18 xenial-vm3 systemd[1]: proc-sys-fs-binfmt_misc.automount: Got automount request for /proc/sys/fs/binfmt_misc, triggered by 1394 (snmpd) Jul 11 11:04:18 xenial-vm3 systemd[1]: Mounting Arbitrary Executable File Formats File System... Jul 11 11:04:18 xenial-vm3 systemd[1]: Mounted Arbitrary Executable File Formats File System. Jul 11 11:04:18 xenial-vm3 automount[1357]: attempting to mount entry /home/test1 <== Jul 11 11:04:18 xenial-vm3 kernel: [8.880685] FS-Cache: Loaded Jul 11 11:04:18 xenial-vm3 kernel: [8.889318] FS-Cache: Netfs 'nfs' registered for caching Jul 11 11:04:18 xenial-vm3 kernel: [8.902672] NFS: Registering the id_resolver key type Jul 11 11:04:18 xenial-vm3 kernel: [8.902680] Key type id_resolver registered Jul 11 11:04:18 xenial-vm3 kernel: [8.902682] Key type id_legacy registered Jul 11 11:04:18 xenial-vm3 automount[1357]: mounted /home/test1 <== Jul 11 11:04:18 xenial-vm3 automount[1357]: attempting to mount entry /home/test2 <== Jul 11 11:04:18 xenial-vm3 kernel: [9.163011] random: nonblocking pool is initialized Jul 11 11:04:18 xenial-vm3 automount[1357]: mounted /home/test2 <=== *** Test Case 2 - Restart snmpd : To reproduce this case, autofs mounts should not be mounted to begin with. (restart autofs or let it expire) #systemctl restart snmpd.service Syslog entries : Jul 11 11:15:40 xenial-vm3 systemd[1]: Stopping LSB: SNMP agents... Jul 11 11:15:40 xenial-vm3 snmpd[1668]: * Stopping SNMP services: Jul 11 11:15:40 xenial-vm3 snmpd[1434]: Received TERM or STOP signal... shutting down... Jul 11 11:15:40 xenial-vm3 systemd[1]: Stopped LSB: SNMP agents. Jul 11 11:15:40 xenial-vm3 systemd[1]: Starting LSB: SNMP agents... Jul 11 11:15:42 xenial-vm3 snmpd[1677]: * Starting SNMP services: Jul 11 11:15:42 xenial-vm3 automount[1357]: attempting to mount
[Sts-sponsors] [Bug 1835818] Re: snmpd causes autofs mount points to be mounted on service start/restart
The attachment "lp1835818_eoan.debdiff" seems to be a debdiff. The ubuntu-sponsors team has been subscribed to the bug report so that they can review and hopefully sponsor the debdiff. If the attachment isn't a patch, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are member of the ~ubuntu-sponsors, unsubscribe the team. [This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issue please contact him.] ** Tags added: patch -- You received this bug notification because you are a member of STS Sponsors, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1835818 Title: snmpd causes autofs mount points to be mounted on service start/restart Status in net-snmp package in Ubuntu: In Progress Status in net-snmp source package in Xenial: In Progress Status in net-snmp source package in Bionic: In Progress Status in net-snmp source package in Cosmic: Won't Fix Status in net-snmp source package in Disco: In Progress Status in net-snmp source package in Eoan: In Progress Bug description: [Impact] Autofs direct map triggers are visible in /etc/mtab. On boot, when snmpd starts, it iterates over the entries in /etc/mtab and performs statfs() on them. This trigger automount to mount autofs mounts even if the user does not explicitly access them. However this happens only if autofs service is started before snmpd. If snmpd stars first /etc/mtab is not yet populated with autofs mounts and therefore are not mounted. When there a few autofs mount points the impact is insignificant. However when there are thousands of them, this causes unnecessary overhead on operations such as df. This also delays the system shutdown time since everything needs to be unmounted. [Test Case] *** Test Case 1 - During boot: The user that brought this issue to our attention would observe all autofs mounts be mounted at boot, because in their environment autofs would start first. In my environment snmpd starts first so to reproduce I had to add a small delay in snmpd init script. In /etc/init.d/snmp : @@ -36,6 +36,8 @@ cd / case "$1" in start) +# Delay snmp start +sleep 2 log_daemon_msg "Starting SNMP services:" # remove old symlink with previous version if [ -L /var/run/agentx ]; then $cat /etc/auto.master /- /etc/auto.nfs --timeout=30 $cat /etc/auto.nfs /home/test1 -fstype=nfs,hard,intr,nosuid,no-subtree-check,tcp :/srv/export/test1 /home/test2 -fstype=nfs,hard,intr,nosuid,no-subtree-check,tcp :/srv/export/test2 Reboot vm, syslog entries : # Autofs starts Jul 11 11:04:16 xenial-vm3 autofs[1295]: * Starting automount... Jul 11 11:04:16 xenial-vm3 automount[1357]: Starting automounter version 5.1.1, master map /etc/auto.master Jul 11 11:04:16 xenial-vm3 automount[1357]: using kernel protocol version 5.02 # Mount triggers, now visible in mtab Jul 11 11:04:16 xenial-vm3 automount[1357]: mounted direct on /home/test1 with timeout 300, freq 75 seconds Jul 11 11:04:16 xenial-vm3 automount[1357]: mounted direct on /home/test2 with timeout 300, freq 75 seconds Jul 11 11:04:16 xenial-vm3 autofs[1295]:...done. ... # SNMP starts Jul 11 11:04:18 xenial-vm3 snmpd[1294]: * Starting SNMP services: Jul 11 11:04:18 xenial-vm3 systemd[1]: proc-sys-fs-binfmt_misc.automount: Got automount request for /proc/sys/fs/binfmt_misc, triggered by 1394 (snmpd) Jul 11 11:04:18 xenial-vm3 systemd[1]: Mounting Arbitrary Executable File Formats File System... Jul 11 11:04:18 xenial-vm3 systemd[1]: Mounted Arbitrary Executable File Formats File System. Jul 11 11:04:18 xenial-vm3 automount[1357]: attempting to mount entry /home/test1 <== Jul 11 11:04:18 xenial-vm3 kernel: [8.880685] FS-Cache: Loaded Jul 11 11:04:18 xenial-vm3 kernel: [8.889318] FS-Cache: Netfs 'nfs' registered for caching Jul 11 11:04:18 xenial-vm3 kernel: [8.902672] NFS: Registering the id_resolver key type Jul 11 11:04:18 xenial-vm3 kernel: [8.902680] Key type id_resolver registered Jul 11 11:04:18 xenial-vm3 kernel: [8.902682] Key type id_legacy registered Jul 11 11:04:18 xenial-vm3 automount[1357]: mounted /home/test1 <== Jul 11 11:04:18 xenial-vm3 automount[1357]: attempting to mount entry /home/test2 <== Jul 11 11:04:18 xenial-vm3 kernel: [9.163011] random: nonblocking pool is initialized Jul 11 11:04:18 xenial-vm3 automount[1357]: mounted /home/test2 <=== *** Test Case 2 - Restart snmpd : To reproduce this case, autofs mounts should not be mounted to begin with. (restart autofs or let it expire) #systemctl restart snmpd.service Syslog entries : Jul 11 11:15:40 xenial-vm3 systemd[1]: Stopping LSB: SNMP agents... Jul 11 11:15:40 xenial-vm3 snmpd[1668]: * Stopping SNMP services: Jul 11 11:15:40 xenial-vm3 snmpd[1434]: Received
