Re: [RFC/PATCH 0/2] support for CMS-formatted disks on the s/390 architecture

[Jonathan Nieder]

Stephen Powell wrote:

> What I propose is four 1-cylinder minidisk
> images of a 3390 DASD device.  They will be (a) a non-reserved
> CMS minidisk with no filesystem (mkfs or mkswap has never been run
> on the partition), (b) a non-reserved CMS minidisk with an ext3
> filesystem on it, (c) a reserved CMS minidisk with no filesystem,
> and (d) a reserved CMS minidisk with an ext3 filesystem.  All
> minidisks will be formatted with a block size of 4096.

Yes, that would be great.  There is no need to worry about the mkfs
step if you don’t want to (so A and C would be sufficient); I can
always add a filesystem myself as long as Linux is able to cope with
the image.

If it is convenient to make, an example with a different block size
would be nice, too.

>> The support is for reading only because that is what is most needed.
>> I don’t imagine there would be any major technical obstacles to
>> teaching parted to write these partitions, too.
>>
>> Thoughts?
>
> Yes, we really don't need disk reorganization tools on z/VM.
[...]
> All we really need is for parted to recognize the pre-existing
> partition on a CMS minidisk so that the Debian installer can make
> use of them.

Understood.

> See http://www.wowway.com/~zlinuxman/diag250.htm for
> an idea of the hoops we currently have to jump through to install
> Debian for s390 to CMS minidisks.

This whole field is unfamiliar to me.  Thank you for the clear
explanations.

Jonathan