Re: [PATCH v3 0/2] Add ceph root filesystem

[Alex Elsayed <eternaleye@gmail.com>]

mark.doffman@codethink.co.uk wrote:

> From: Mark Doffman <mark.doffman@codethink.co.uk>
> 
> Hi All,
> 
> The following is a third version of a patch series that adds the ability
> to use a ceph distributed file system as the root device.
<snip>

Would you mind expanding on why you want to do this in the kernel, instead 
of using an initramfs? For example, dracut supports the following syntax, 
and sets it up using the same tools as mounting NFS in a running system 
rather than the kernel's nfsroot support:

root=nfs:[<server-ip>:]<root-dir>[:<nfs-options>]
root=nfs4:[<server-ip>:]<root-dir>[:<nfs-options>]
root={dhcp|dhcp6}

root=dhcp alone directs initrd to look at the DHCP root-path where NFS 
options can be specified.

It also supports CIFS, as a further illustration:

root=cifs://[<username>[:<password>]@]<server-ip>:<root-dir>

Extending this to Ceph seems much simpler than implementing such a thing in 
the kernel, especially given dracut's modular nature, and it's easy enough 
to compile an initramfs into the kernel.