[16:08] <xnox> cpaelzer, can i fake an ECKD drive with like file loop mounts?
[16:08] <xnox> cpaelzer, to lift raw track data... even though the underlying is just a loop mount.
[16:08] <xnox> in a QEMU kvm, not a z/vm
[16:13] <cpaelzer> xnox: ah you have a raw track image and want to load that
[16:13] <cpaelzer> xnox: how about dd it onto a spare dasd and providing that to the guest then?
[16:13] <cpaelzer> so on host dd to disk
[16:13] <cpaelzer> and then add the dasd to the guest
[16:13] <cpaelzer> that is kind of a loop mount, but with a spare dasd instead of /dev/loop
[16:13] <xnox> cpaelzer, i have no dasd at all.
[16:14] <xnox> cpaelzer, i'm in kvm, need to create a raw track data dump. somehow =)
[16:16] <xnox> cpaelzer, because for a z/vm cloud; i need to ship raw track data dump, not a tarball.
[16:18] <cpaelzer> oh "inside" kvm
[16:18] <cpaelzer> not on the host
[16:18] <cpaelzer> I actually don't know
[16:18] <cpaelzer> borntraeger: ^^
[16:18] <cpaelzer> hca: ^^
[16:20] <borntraeger> xnox, cpaelzer, not sure what you are trying to achieve.
[16:20] <borntraeger> what kind of system do you have and what do you want to do
[16:20] <cpaelzer> borntraeger: being inside a KVM guest and having a raw image of track data
[16:20] <cpaelzer> borntraeger: being abel to mount it
[16:20] <cpaelzer> that is the case xnox has if I got it right
[16:21]  * cpaelzer feels there is an answer of the "you should know" kind coming
[16:21] <borntraeger> what raw track image is this? How was it created?
[16:21] <cpaelzer> xnox: what was the source ?
[16:22] <xnox> cpaelzer, borntraeger, for normal ubuntu cloud images, we create a empty file, kparxt connect it, create partition table, debootstrap things on it, run zipl, unmount. and that ends up being a cloud image in qcow2 format that is bootable in s390x Ubuntu Openstack.
[16:23] <xnox> cpaelzer, borntraeger - now, for the L1CC (original) / z/VM cloud connector / nova-zvm it needs raw track data. Thus in the past i would ssh into a z/VM
[16:24] <borntraeger> So its an image file for z/VM guests?
[16:26] <borntraeger> xnox, still do not get what kind of raw track file you have and how it was created
[16:26] <xnox> and then i would qemu-nbd mount this qcow2 image, dd it onto a dasd drive, re-run zipl, switch the drive into raw track access mode, package that as a file and ship it to glance
[16:26] <xnox> from where nova-zvm-driver takes that raw track data file, blasts it onto ECKD dasd drive to provision new z/vms
[16:27] <xnox> however, currently launchpad builds everything in containers, and we create qcow2 image statically. And ideally, I should be able to create a raw track data of an eckd drive, without having a physical dasd drive to mangle.
[16:27] <borntraeger> so you use a Linux under z/VM with the dasd driver in raw access mode to access the raw tracks after you have filled it with "normal means"
[16:27] <xnox> borntraeger, can nova-zvm-driver use a non-raw-track-data image? but like a regular qcow2/raw iamge?
[16:28] <borntraeger> xnox, I have no clue whatsoever about the z/Vm openstack driver
[16:28] <cpaelzer> xnox: borntraeger knows everything but likely wants to stay away from nova-zvm things :-)
[16:28] <xnox> borntraeger, currently yes; but ideally i do not want to =/ because my stock build environment has no dasd drives that i can abuse.
[16:29] <xnox> borntraeger, i'm after to qemu-img convert -> raw track data; because surely it should be possible for the linux kernel, and/or userspace construct track data, which when dd'ed onto a dasd drive in raw track mode just "magically works"
[16:30] <xnox> borntraeger, is there a defined data format of what raw track data is?
[16:30] <borntraeger> xnox, I am sure that there is some way to construct the track data out of block data
[16:30] <borntraeger> xnox, but I do not know
[16:30] <borntraeger> xnox, maybe somewhere in the zdsfs fuse tool you find information about the track format
[16:31] <borntraeger> xnox, s390tools/libzds/
[16:32] <cpaelzer> borntraeger: do you think it would make sense to write to linux-s390 mailing list with that
[16:33] <cpaelzer> borntraeger: for the other devs around you to check their toolboxes if one has something that achieves that?
[16:33] <borntraeger> cpaelzer, yes  maybe.
[16:35] <borntraeger> xnox, cpaelzer, wouldnt it be better if z/VM openstack would support a raw image?
[16:35] <cpaelzer> oh yes of course
[16:36] <borntraeger> the openstack thing uses xcat, which uses a Linux
[16:36] <xnox> borntraeger, as long as i can force zipl to create the right boot code which would be bootable off dasd....
[16:36] <borntraeger> so I would assume that this is possible
[16:36] <borntraeger> xnox, you can force all kind of things with zipl
[16:36] <xnox> borntraeger, my understand was that blasting raw image onto dasd, wouldn't end up with the right bootcode. I should test it.
[16:37] <borntraeger> zipl.conf has targettype (e.g. CDL)
[16:37] <borntraeger> and targetgeometry
[16:37] <xnox> borntraeger, who can i talk to about image formats that the newly rewritten cloud connector supports.
[16:37] <borntraeger> and targetblocksize
[16:37] <borntraeger> xnox, no idea. its not us in Boeblingen
[16:37]  * xnox somehow thought that zipl for CDL ends up on stuff outside of raw image and somewhere before it in the raw track data, but i guess not.
[16:38] <borntraeger> xnox, its on the first track which is smaller than the usual 4k
[16:38] <borntraeger> but when you write it the dasd driver ignores the additional bytes and fakes 4k
[16:40] <xnox> borntraeger, right but the first track is "accesible" by dd when basting things to /dev/dasda which is in non-raw mode. ack.
[16:40] <borntraeger> yes
[16:40] <xnox> cool.
[16:41] <borntraeger> xnox, "newly rewritten cloud connector" refers to whatever is on z/VM I guess?
[16:41] <borntraeger> xnox, for the kvm openstack mpavone should be able to tell you everything
[16:42] <xnox> borntraeger, i believe it refers to the "old xcat thing stuff to do openstack instances in z/vm" but rewritten / renamed / upgraded for newer openstack.
[16:43] <xnox> borntraeger, kvm openstack is all good. we ship cloud images that are usable directly - just add a config drive, and voila.