17 May
2021
17 May
'21
12:19 a.m.
Hey Markus, Ilya,
you don't know with how much interest I am following this thread,
because ...
... we have been looking for a while to a discussion about using RBD
(not cephfs) as a replacement for a hard disk. Linux can map RBD
devices, so should Linux not also be able to *boot* from an rbd device
similar to a regular disk?
I did not find any example of this yet, but I'd assume that conceptually
one would probably:
- preload a Linux kernel from the network (potentially via ipxe)
- specify root=rbd://fsid/pool/image
Or in a even *better* variant:
- the bootloader (ipxe?) can map RBD
- the bootloader pre-loads enough of the image for reading the partition
- the bootloader either loads the kernel + initramfs *or* chainloads
another bootloader
What are your thoughts on this? Do-able or totally crazy?
Best regards,
Nico
--
Sustainable and modern Infrastructures by ungleich.ch
Generally it
would be great if you could include the proper initrd code for RBD and CephFS root
filesystems to the Ceph project. You can happily use my code as a starting point.
https://github.com/trickkiste/ltsp/blob/feature-boot_method-rbd/debian/ltsp…
I think booting from CephFS would require kernel patches. It looks
like NFS and CIFS are the only network filesystems supported by the
init/root infrastructure in the kernel.