[systemd-devel] Help! iSCSI based file systemd with "_netdev" causing ordering cycles to occur (random services and mounts fail)

[Andrei Borzenkov]

On Fri, Oct 27, 2023 at 5:01 AM Tony Rodriguez <unixpro1970 at gmail.com> wrote:
>
> Experiencing this same issue with iSCSI and systemd-239 for RH8/Rocky8
> and RH9/Rocky9 system-252. Nothing was done on my end to create this
> issue.  In other words, no custom mount/unit files or services, just
> your typical ISO install and rpm updates.
>
> An ordering cycle occurs, when "_netdev" is specified within /etc/fstab
> for systemd.  This happens with systemd-239-14 and systemd-239-18 using
> iSCSI based file systems.    Seems others are experiencing this as well
> (see link below).  I can also confirm this happens with systemd-252
> (RH9/Rocky9)l. Especially if "_netdev" is used with either "/var" or
> "/usr" iSCSI based devices/file systems.  The system may not boot, may
> not mount file systems, may not start services/unit files, and the
> system becomes slow during system boot.
>
> Does anyone know of a fix/patch and root cause for this?
>
> Please see this link:
> https://issues.redhat.com/browse/RHEL-12987?jql=project%20%3D%20RHEL%20AND%20affectedVersion%20%3D%20rhel-9.2.0%20AND%20text%20~%20%22iscsi%22
>
> # cat /etc/fstab
> [...]
> /dev/mapper/rhel-root /                       xfs     defaults,_netdev 0 0
> UUID=2177a7fc-bc41-43e4-bdc1-d231a5eb4680 /boot xfs     defaults,_netdev 0 0
> /dev/mapper/rhel-tmp /tmp                    xfs     defaults,_netdev 0 0
> /dev/mapper/rhel-var /var                    xfs
> defaults,_netdev,x-initrd.mount 0 0
> /dev/mapper/rhel-var_log /var/log                xfs
> defaults,_netdev 0 0
> /dev/mapper/rhel-var_tmp /var/tmp                xfs
> defaults,_netdev 0 0
>
> # journalctl -b | grep deleted
> Oct 13 08:15:35 vm-isci8 systemd[1]: basic.target: Job tmp.mount/start
> deleted to break ordering cycle starting with basic.target/start
> Oct 13 08:15:35 vm-isci8 systemd[1]: network.target: Job
> network-pre.target/start deleted to break ordering cycle starting with
> network.target/start
> Oct 13 08:15:35 vm-isci8 systemd[1]: NetworkManager.service: Job
> dbus.socket/start deleted to break ordering cycle starting with
> NetworkManager.service/start
>

Showing the actual chain that caused the loop would be helpful. Did
not systemd print it?

> # mount | grep " /tmp "
> --> not mounted
>
> # systemctl status dbus.socket
> ● dbus.socket - D-Bus System Message Bus Socket
>     Loaded: loaded (/usr/lib/systemd/system/dbus.socket; static; vendor
> preset: enabled)
>     Active: inactive (dead)
> --> not started