On Dec 2, 2010, at 12:09 PM, Jim Rees wrote: > Chuck Lever wrote: > > On Dec 1, 2010, at 7:18 PM, Jim Rees wrote: > >> If I boot diskless with nfsroot, why is the root file system mounted >> readonly? This makes sense for a file system on disk, since it may have to >> be checked before remounting rw, but I don't see why this is needed for >> nfsroot. >> >> Also, Documentation/filesystems/nfs/nfsroot.txt says that only nfs options >> can be given on the kernel nfsroot option, but I've seen a claim that you >> can also put "rw" here. Are other generic options possible? How about the >> nfs options that aren't listed in the doc? Should the doc be updated? > > What kernel version are you looking at? I think 2.6.37-rc has some > nfsroot updates that allow all NFS options to be used. > > Not sure about the generic mount options. Why not just try them and see? > > This is Ubuntu lucid, so 2.6.32. I'm less concerned about the documentation > defect than the question about the default being readonly. Is there any > good reason other than to match the behavior of non-nfs root? > > I ask because there has been a bug in ubuntu for a long time (a couple of > releases) that prevents nfsroot from working. Their mountall is broken and > can't remount an nfs root rw. They need to fix this obviously, but it got > me to wondering why the remount should be needed at all. > > The bug report is here: > https://bugs.launchpad.net/ubuntu/+source/mountall/+bug/537133 OK, Ubuntu doesn't use NFSROOT (the kernel's implementation), it actually does a real mount in user space. So all the normal NFS and generic mount options ought to work. However, I worked on the kernel's implementation recently, not Ubuntu's "nfsroot", so that's as far as my expertise goes. -- Chuck Lever chuck[dot]lever[at]oracle[dot]com -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
