Bug 1356188
| Summary: | /etc/hostname change no longer takes effect immediately | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Scott Poore <spoore> |
| Component: | NetworkManager | Assignee: | Beniamino Galvani <bgalvani> |
| Status: | CLOSED NOTABUG | QA Contact: | Desktop QE <desktop-qa-list> |
| Severity: | high | Docs Contact: | |
| Priority: | high | ||
| Version: | 7.3 | CC: | atragler, bgalvani, lrintel, mleitner, pkis, rkhan, sukulkar, systemd-maint-list, thaller |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2017-07-13 20:25:14 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
From systemd point of view this is a configuration file which tells what hostname should be set during boot. There must be something else that watches it and change the hostname in kernel and my suspect is Network Manager: [root@old ~]# hostname old [root@old ~]# echo myold > /etc/hostname [root@old ~]# hostname old [root@old ~]# systemctl start NetworkManager [root@old ~]# hostname myold [root@old ~]# echo old > /etc/hostname [root@old ~]# hostname old čec 14 08:33:36 old NetworkManager[955]: <info> Setting system hostname to 'myold' (from system configuration) čec 14 08:33:47 old NetworkManager[955]: <info> Setting system hostname to 'old' (from system configuration) čec 14 08:33:57 old NetworkManager[955]: <info> Setting system hostname to 'myold' (from system configuration) čec 14 08:34:09 old NetworkManager[955]: <info> Setting system hostname to 'old' (from system configuration) čec 14 08:35:07 old NetworkManager[955]: <info> Setting system hostname to 'myold' (from system configuration) čec 14 08:35:16 old NetworkManager[955]: <info> Setting system hostname to 'old' (from system configuration) čec 14 08:50:12 myold NetworkManager[955]: <info> Setting system hostname to 'myold' (from system configuration) čec 14 08:50:13 myold NetworkManager[955]: <info> Setting system hostname to 'old' (from system configuration) FYI, from the hosts I'm testing on, I see these versions: -------------- rhel7.3 --------------------- NetworkManager-1.4.0-0.3.git20160621.072358da.el7.x86_64 -------------- rhel7.2 --------------------- NetworkManager-1.0.6-27.el7.x86_64 I do see NetworkManager running on both. AFAIK all the RHEL documentation suggests to use hostnamectl or nmcli/nmtui to change the system hostname, and writing /etc/hostname directly to do so only worked in RHEL 7.2 because we used to monitor changes to the file to detect when hostnamectl updated the hostname; but in this way we also caught manual changes to the file. Now we monitor hostnamectl properties on D-Bus to detect a change of the hostname and thus writing the file doesn't have effect on the system hostname. In my opinion this is correct as a change to the file should not reconfigure automatically the system. It's also consistent with hostnamed/hostnamectl (which doesn't pick up changes to the file). All changes should go through either hostnamed or nmcli/nmtui. Ok, that explains the change in behavior. Should this be documented somewhere in 7.3 release notes or one of the guides? Thanks, Scott *** Bug 1359222 has been marked as a duplicate of this bug. *** This was documented in RHEL 7.3 Release Notes: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/7.3_Release_Notes/new_features_networking.html and in the Networking Guide. |
Description of problem: In RHEL7.2 and earlier, it seems as if updating /etc/hostname changed the hostname immediately. Now it does not. I have to either run hostname or hostnamectl command. Is this a documented change in behavior? Or was this maybe a fix of a bug in the old version? Example of what I'm seeing in additional info. Version-Release number of selected component (if applicable): systemd-219-23.el7.x86_64 How reproducible: always as far as I can tell. Steps to Reproduce: 1. echo "<new hostname>" > /etc/hostname 2. hostname Actual results: shows same hostname Expected results: used to show new/changed hostname Additional info: ------------ [ rhel7.2 ] ----------------------- rhel_7.2_vm # hostname vm3.example.com rhel_7.2_vm # cat /etc/hostname vm3.example.com rhel_7.2_vm # echo newhostname > /etc/hostname rhel_7.2_vm # hostname newhostname rhel_7.2_vm # rpm -q systemd systemd-219-19.el7.x86_64 ------------ [ rhel7.3 ] ----------------------- rhel_7.3_vm # hostname rhel7-3.example.com rhel_7.3_vm # cat /etc/hostname rhel7-3.example.com rhel_7.3_vm # echo newhostname > /etc/hostname rhel_7.3_vm # hostname rhel7-3.example.com rhel_7.3_vm # sleep 60 rhel_7.3_vm # hostname rhel7-3.example.com rhel_7.3_vm # hostnamectl Static hostname: newhostname Transient hostname: rhel7-3.example.com Icon name: computer-vm Chassis: vm Machine ID: 71a559c395354fe6977d702cba94da9d Boot ID: fcb10e5ea4d34b17ae04c942c23f7ab6 Virtualization: kvm Operating System: Red Hat Enterprise Linux Server 7.3 Beta (Maipo) CPE OS Name: cpe:/o:redhat:enterprise_linux:7.3:beta:server Kernel: Linux 3.10.0-467.el7.x86_64 Architecture: x86-64 rhel_7.3_vm # hostname newhostname rhel_7.3_vm # hostnamectl Static hostname: newhostname Icon name: computer-vm Chassis: vm Machine ID: 71a559c395354fe6977d702cba94da9d Boot ID: fcb10e5ea4d34b17ae04c942c23f7ab6 Virtualization: kvm Operating System: Red Hat Enterprise Linux Server 7.3 Beta (Maipo) CPE OS Name: cpe:/o:redhat:enterprise_linux:7.3:beta:server Kernel: Linux 3.10.0-467.el7.x86_64 Architecture: x86-64