Am Mo., 17. Mai 2021 um 20:28 Uhr schrieb Nico Schottelius < nico.schottelius@xxxxxxxxxxx>: > > > Markus Kienast <mark@xxxxxxxxxxxxx> writes: > > > Hi Nico, > > > > we are already doing exactly that: > > > > Loading initrd via iPXE > > which contains the necessary modules and scripts to boot an RBD boot dev. > > Works just fine. > > Interesting and very good to hear. How do you handle kernel differences > (loaded kernel vs. modules in the RBD image)? > The way it works in LTSP is, that you run a script provided by the ltsp project, which copies the kernel to your tftpboot directory and sets the ipxe boot options accordingly. Currently there is no automatism for mapping and mounting the RBD for this purpose, you have to map it by hand and mount it to the proper dir prior to running the script. I am sure you can integrate this into your workflow by using what is currently in ltsp and my rbd branch as an example. > > > And Ilya just helped to work out the last show stopper, thanks again for > > that! > > > > We are using a modified LTSP system for this. > > > > We have proposed some patches to LTSP to get the necessary facilities > > upstream but Alkis Georgopoulos first want to see that there is enough > > interest for that before he considers merging our patch or creating the > > necessary changes himself. > > I think seeing LTSP booting on RBD is a great move forward, also for > other projects. > > > However the necessary initrd code is already available in this merge > > request: > > > https://github.com/trickkiste/ltsp/blob/feature-boot_method-rbd/debian/ltsp-rbd.initramfs-script > > > > I see you are from Switzerland - neighbors! > > We might actually meet at a Linuxtag - but we should probably take this > off-list :-) > In Vienna? Not been there for ages but happy to meet. > > > Out of interest, what are you planning to use this for? Servers, Thin/Fat > > Clients? > > Our objective in the end is to boot servers and VMs from possible the > same RBD pool/images. > > The problem there is though that we don't know what is inside the RBD > image, so we don't know which kernel to load besides we would do some > kind of kexec magic, which would pass on the RBD parameters. > > Or in other words, we have this use case: > > - a customer books a VM and needs more performance > - the customer decides to go with *a* server, but not necessarily a > specific server > - the customer VM should be shutdown and the RBD image should boot on a > server > > If the server crashes, the OS should be booted on a different server. > > We can obviously work around this by *always* running a VM, but this is > not exactly what our customers want. At the moment they use local disks > + nfs shares to achieve a similar solution, but it is far from perfect. > Alright, I understand. Yes, your scenario would work, while you would only need to borrow the ipxe stuff from LTSP and my rbd initramfs-hook and initramfs-script. The initramfs stuff should actually be molded into a separate Ubuntu package and made available to upstream. The mapping RO stuff, which Ilya has provided yet needs to be added and all the other available kernel options should be made available as well. My best regards Markus > > Cheers, > > Nico > > -- > Sustainable and modern Infrastructures by ungleich.ch > _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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