[Pkg-iscsi-maintainers] Bug#850060: open-iscsi initramfs scripts do not start up iscsiuio deamon

[Christian Seiler]

Control: tags -1 + confirmed moreinfo
Control: severity -1 wishlist

On 01/03/2017 06:02 PM, Andrew Patterson wrote:
> Version 2.0.874 of the open-iscsi package requires that the iscsiuio
> daemon to be running before iscsi hardware offload cards can login to
> a LUN. The initramfs scripts used by open-iscsi to support boot from
> iSCSI do no start up this daemon resulting in a failed boot.

I'd really like to support this setup. My idea how this could work
would be along the lines of the following:

 1. In the local-top hook start iscsiuio before calling iscsistart -b
    or iscsistart $params if the binary is present in the initramfs.

 2. In the iscsiuio package install a initramfs hook that copies the
    iscsiuio binary (luckily it doesn't depend on any library) into
    the initramfs.

Together that should start iscsiuio in the initramfs and allow
login to the targets there - but if iscsiuio is not installed, the
user won't see a difference from today.

However, there are still some questions I'd like to have answered
before proceeding - and since I don't have the corresponding hardware
I have no idea what the right answers are:

How does the rest of the boot process proceed then? What happens
when iscsiuio is to be started regularly at boot from the systemd
service / init script? Is the iscsiuio from the initramfs required
to be running at all times during the iSCSI session or can it be
restarted, as long as the time during which that happens is brief
enough? Is it required to be kept around during shutdown if it's
on iSCSI? Does it follow systemd's process name convention to make
sure systemd doesn't kill it during shutdown?

Before I add the aforementioned steps 1 & 2 I'd like to be sure that
this actually works properly beyond the initramfs. So any
information related to that would be appreciated.

Regards,
Christian