Bug#808041: s390-zfcp: Install Debian on FC-attached SCSI devices on s390

[Hendrik Brueckner]

Package: d-i.debian.org
Severity: normal
Tags: d-i

Dear Debian Installer Team and Maintainers,

I would like to contribute a new package for the Debian Installer
to configure FCP devices and install Debian on SCSI devices which
are available on Linux on z Systems.

FCP device provide access to SAN storage, for example, SCSI devices.
SCSI devices and DASD devices are the main storage devices on a mainframe.

With the FCP configuration utility, users can enable FCP devices.
Depending on the hardware configuration of the FCP devices, LUNs will
be automatically detected and attached; alternatively, users are guided
to manually add LUNs. The FCP configuration utility can be preseeded
to perform an unattended configuration of FCP devices.

I will attach the patches for this new utility, as well as, a README
with more details in another mail.

Feedback for the FCP configuration utility is very welcome!
I am looking forward to discuss and work with you on the steps to make
it available with the Debian Installer.

Thank you very much!

Kind regards,
Hendrik

[Cyril Brulebois]

Hi!

Post by Hendrik Brueckner
Package: d-i.debian.org
Severity: normal
Tags: d-i
Dear Debian Installer Team and Maintainers,
I would like to contribute a new package for the Debian Installer
to configure FCP devices and install Debian on SCSI devices which
are available on Linux on z Systems.
FCP device provide access to SAN storage, for example, SCSI devices.
SCSI devices and DASD devices are the main storage devices on a mainframe.
With the FCP configuration utility, users can enable FCP devices.
Depending on the hardware configuration of the FCP devices, LUNs will
be automatically detected and attached; alternatively, users are guided
to manually add LUNs. The FCP configuration utility can be preseeded
to perform an unattended configuration of FCP devices.
I will attach the patches for this new utility, as well as, a README
with more details in another mail.
Feedback for the FCP configuration utility is very welcome!
I am looking forward to discuss and work with you on the steps to make
it available with the Debian Installer.

Thanks! I'm adding Philipp and S/390 people in copy so that we get as
many eyes as possible on your proposed patches. I'm afraid I don't know
much about this platform for one thing, and lack time to learn more
about it right now for another; sorry about that. :/

Mraw,
KiBi.

[Dimitri John Ledkov]

Hi!

Post by Cyril Brulebois
Hi!

Post by Hendrik Brueckner
Package: d-i.debian.org
Severity: normal
Tags: d-i
Dear Debian Installer Team and Maintainers,
I would like to contribute a new package for the Debian Installer
to configure FCP devices and install Debian on SCSI devices which
are available on Linux on z Systems.
FCP device provide access to SAN storage, for example, SCSI devices.
SCSI devices and DASD devices are the main storage devices on a mainframe.
With the FCP configuration utility, users can enable FCP devices.
Depending on the hardware configuration of the FCP devices, LUNs will
be automatically detected and attached; alternatively, users are guided
to manually add LUNs. The FCP configuration utility can be preseeded
to perform an unattended configuration of FCP devices.
I will attach the patches for this new utility, as well as, a README
with more details in another mail.
Feedback for the FCP configuration utility is very welcome!
I am looking forward to discuss and work with you on the steps to make
it available with the Debian Installer.

Thanks! I'm adding Philipp and S/390 people in copy so that we get as
many eyes as possible on your proposed patches. I'm afraid I don't know
much about this platform for one thing, and lack time to learn more
about it right now for another; sorry about that. :/

I'm part of debian-installer team, and have been mostly uploading
partman-* et.al. packages. So I don't know all of the d-i, but do have
a fairly good working knowledge of it. I certainly can review /
sponsor things for you.

I also have access to s390x hardware to test things out. But my s390x
specific skills are extremely basic at the moment. I can just about
ipl things to get me into installer.

[Hendrik Brueckner]

Hi Dimitri,

Post by Dimitri John Ledkov

Post by Cyril Brulebois

Post by Hendrik Brueckner
Package: d-i.debian.org
Severity: normal
Tags: d-i
Dear Debian Installer Team and Maintainers,
I would like to contribute a new package for the Debian Installer
to configure FCP devices and install Debian on SCSI devices which
are available on Linux on z Systems.
FCP device provide access to SAN storage, for example, SCSI devices.
SCSI devices and DASD devices are the main storage devices on a mainframe.
With the FCP configuration utility, users can enable FCP devices.
Depending on the hardware configuration of the FCP devices, LUNs will
be automatically detected and attached; alternatively, users are guided
to manually add LUNs. The FCP configuration utility can be preseeded
to perform an unattended configuration of FCP devices.
I will attach the patches for this new utility, as well as, a README
with more details in another mail.
Feedback for the FCP configuration utility is very welcome!
I am looking forward to discuss and work with you on the steps to make
it available with the Debian Installer.

Thanks! I'm adding Philipp and S/390 people in copy so that we get as
many eyes as possible on your proposed patches. I'm afraid I don't know
much about this platform for one thing, and lack time to learn more
about it right now for another; sorry about that. :/

I'm part of debian-installer team, and have been mostly uploading
partman-* et.al. packages. So I don't know all of the d-i, but do have
a fairly good working knowledge of it. I certainly can review /
sponsor things for you.

Great! Thank you very much for helping me and it would be amazing if you
could act as sponsor.

Post by Dimitri John Ledkov
I also have access to s390x hardware to test things out. But my s390x
specific skills are extremely basic at the moment. I can just about
ipl things to get me into installer.

That's good to know ;-) First of all, if you questions regarding s390x,
do not hesitate to ask me or the debian-s390 mailing list. If you can
IPL the system and get into the installer, you have already master lots
of things. Within the Linux instance, then, things looks similar to Linux
on other platforms.... maybe except the way how devices are managed.

Let me provide some more insights into device management on the mainframe
because that's one of the fundamental differences to other platforms.

A mainframe is a large system and there can be numerous devices. These
devices managed through an I/O subsystem, called the channel subsystem.
To handle devices on the channel subsystem, the Linux kernel provides a
dedicated layer, the common I/O layer (CIO). This layer represents the
maninframe (s390) devices to Linux. A device on the channel subsystem
is represented by a bus-ID in Linux, for example, 0.0.1224. The "1234"
portion is the device number ranging from 0000 to FFFF. Managing this
range of possible devices can be complex.

Due to the complexity, devices are disabled by default. Hence, devices
that the Linux instances require must be enabled first, i.e., the devices
must be set online. This step can include some device configuration
changes.
After the devices are enabled, they appear to the Linux instance, for
example, as DASDs or FCP devices. Some device configuration can or must
be performed at enablement.

This particular enablement step is unique to Linux on the mainframe.
After enablement, device management is similar to other Linux platforms.

So that's why there the DASD and the FCP device configuration module: to
enable DASD and FCP devices and block devices and SCSI devices available
to the Linux instance. Then, they can be partitioned like any other
SCSI disk.


Thanks and kind regards,
Hendrik
--
Hendrik Brueckner
***@linux.vnet.ibm.com | IBM Deutschland Research & Development GmbH
Linux on z Systems Development | Schoenaicher Str. 220, 71032 Boeblingen


IBM Deutschland Research & Development GmbH
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Geschaeftsfuehrung: Dirk Wittkopp
Sitz der Gesellschaft: Boeblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294

[Philipp Kern]

Hendrik,

Post by Hendrik Brueckner
So that's why there the DASD and the FCP device configuration module: to
enable DASD and FCP devices and block devices and SCSI devices available
to the Linux instance. Then, they can be partitioned like any other
SCSI disk.

(I have installed Debian on zFCP in the past, but I moved it from zVM.)

Is there a way I could test FCP installation? As far as I understand
there is no emulation of a zFCP-like setup anywhere right, and you'd
need to have access to a zFCP controller?

(Which are harder to partition/segment than DASD-based storage…)

Kind regards
Philipp Kern

[Philipp Kern]

Control: tag -1 + pending

...

Post by Philipp Kern
Is there a way I could test FCP installation? As far as I understand
there is no emulation of a zFCP-like setup anywhere right, and you'd
need to have access to a zFCP controller?
(Which are harder to partition/segment than DASD-based storage )

...
Thanks for pushing the patches!
I don't know of FCP emulation either. To test the module, you would
indeed have to have a zFCP HBA defined plus the necessary storage
network setup (with zoning/LUN masking) configured.
As I already have tested Hendrik's original patchset, building off of
the d-i repository will probably not lead to new insights. I could
however offer to re-run tests once a udeb is built for s390-fcp.
If I can provide additional info (logs of an install, screenshots, ...),
I'd be more than happy to do so.

Going forward I am concerned with any possibility to regression test
this. I'd be helpful to arrange access for a crash-and-burn VM with a
zFCP HBA attached somewhere. (I know that this is difficult because it
also requires more elaborate storage zoning.)

The other case I'm wondering about is how well the installer will handle
the non-presence of DASDs and the co-existence of both.

In other news I just pushed the package to Debian NEW. There might be
concerns about the proper labeling of the license, in which case we need
to iterate a bit. But the package itself looked ready to upload.

Kind regards and thanks
Philipp Kern

[Hendrik Brueckner]

Hi!

Post by Cyril Brulebois

Post by Hendrik Brueckner
Package: d-i.debian.org
Severity: normal
Tags: d-i
Dear Debian Installer Team and Maintainers,
I would like to contribute a new package for the Debian Installer
to configure FCP devices and install Debian on SCSI devices which
are available on Linux on z Systems.
FCP device provide access to SAN storage, for example, SCSI devices.
SCSI devices and DASD devices are the main storage devices on a mainframe.
With the FCP configuration utility, users can enable FCP devices.
Depending on the hardware configuration of the FCP devices, LUNs will
be automatically detected and attached; alternatively, users are guided
to manually add LUNs. The FCP configuration utility can be preseeded
to perform an unattended configuration of FCP devices.
I will attach the patches for this new utility, as well as, a README
with more details in another mail.
Feedback for the FCP configuration utility is very welcome!
I am looking forward to discuss and work with you on the steps to make
it available with the Debian Installer.

Thanks! I'm adding Philipp and S/390 people in copy so that we get as
many eyes as possible on your proposed patches.

Thank you... CCing is more clear. I initially added Philipp and the s390
mailing using X-Debbugs-CC.

Post by Cyril Brulebois
I'm afraid I don't know
much about this platform for one thing, and lack time to learn more
about it right now for another; sorry about that. :/

No problem. Getting access to s390 hardware is a bit difficult.
But any help and feedback regarding the integration into debian
and the debian installer is very helpful.

Thanks and kind regards,
Hendrik