Re: Mounting NFS root FS

From: Janne Karhunen
Date: Mon Dec 04 2006 - 12:12:58 EST


On Monday 04 December 2006 17:29, Trond Myklebust wrote:

> > > I have been trying to make FC5's kernel do a boot
> > > with an NFS root file system. I see the support is in the
> > > kernel(?).
> >
> > Is this really properly possible (with read/write access and
> > locking in place)? AFAIK NFS client lock state data seems
> > to require persistent storage .. ?
>
> 1) Yes, but not on the root partition (unless you use an initrd to start
> rpc.statd before mounting the NFS partition).

Ok.


> 2) NFS provides persistent storage.

To me this sounds like a chicken and an egg problem. It
both depends and provides this at the same time :/. But
hey, if it's supposed to work then OK.

Anyhoo, I tried this at some stage and failed as random
clients seemed to occasionally get stuck in insmod at
boot (infinite wait on lock that never gets released).
At that stage guess was that server could not properly
recognize client reboot given stale client lock data.
But if it's supposed to work I guess I have to give it
another shot and do better analysis on it.

What about NLM/NSM protocol issues - do they properly
deal with packet loss and clients that stay down (client
holding a lock crashing and staying down; will the lock
ever be released)?

 And why does insmod require a lock on module at load??


--
// Janne
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