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

[Lennart Poettering]

On Mo, 30.10.23 10:17, Lennart Poettering (lennart at poettering.net) wrote:

> On Fr, 27.10.23 20:46, Tony Rodriguez (unixpro1970 at gmail.com) wrote:
>
> > Andrea asked for more details so I have provide this verbose output.
> >
> > 1) Lennart's recommendation of removing "/tmp" within /etc/fstab and using
> > tmpfs for "/tmp" appears to stop the dependency issue for systemd-239 for
> > systemd-252.  However, RH8 and RH9 don't support systemd-networkd, I am
> > wondering how this can be overcome if removing "/tmp" and using "tmpfs"
> > aren't options?  Would I have to modify various services and targets? What
> > would I need to add or remove within services and targets to avoid these
> > dependencies?
>
> This is something you'd have to ask your OS vendor. If they don't
> support netwokrd, they will support something else, and maybe it has a
> way to run in early boot or initrd.
>
> Booting without /tmp/ mounted during early boot is simply not
> supported from upstream, sorry, can't help you there. Please contact
> your OS vendor if they can help you.
>
> > 2) On another note, with RH9 systemd-252-14/systemd-252-18 and iscsi, new
> > dependency issues occur if "_netdev" within /etc/fstab is specified for
> > "/var" or "/usr".
>
> If /usr/ is split off it *must* be mounted even earlier than /tmp/: it
> must be mounted in the initrd, nothing else is supported, sorry.
>
> If /var/ is split off it must be mounted at the same point as /tmp/,
> i.e some time in early boot, not necessarily in the initrd though.

Since we never documented this properly I have put together another
piece of documentation that summarizes the requirements on mounts and
when they must be available during boot:

https://github.com/systemd/systemd/pull/29761

You can see the rendered version here (until the next PR push that is)

https://github.com/systemd/systemd/blob/87828aae4712bdb300101b05911392c43d081a6b/docs/MOUNT_REQUIREMENTS.md

Lennart

--
Lennart Poettering, Berlin