Re: [Nbd] nbd for large scale diskless linux

[dsuchod <dsuchod@...65...>]

Hi!

> > Unfortunately SuSE does not provide a nbd package, so didn't try it
> > from a SuSE server system (same architecture, 2.6.11 amd64 kernerl)
> > yet ... but that could be done in some next steps ...
> 
> The server's kernel isn't all that important, really. Nbd-server does
> use <linux/nbd.h>, but that's only to get some constants it needs for
> the protocol -- if you copy that one file, you can theoretically build
> it on every POSIX compliant system (and I'm sure it has been built
> successfully on at least The Hurd and on FreeBSD, since I've tried it on
> those myself)

I build the binaries without problems on the SuSE system. I have checked: 
With the next SuSE10.0 release the nbd package is part of it (not the
opensuse, but within the boxed version) ...

> > I was using the 2.7.3 client tools from the sourceforge repository and:
> > 
> > lp-srv02a:~# nbd-server --help
> > This is nbd-server version 2.7.3

Is 2.7.4 on the next SuSE then.

> cowloop? Is that a specific kernel feature?

Yes it is another kernel package, but not in the mainstream kernel yet. It 
is an block level alternative to unionfs (which is not stable enough to 
use in production environment - at least the diskless clients).
 
> If it's the copy-on-write option in nbd you're talking about then please
> don't do it. It's ugly and dogslow, I should've kicked it out ages ago.

I read that on the enbd pages. They talk on that feature somewhere. But I 
do not know how they do that (file in ramdisk or writeable space somewhere
or directly to ram) ... I post a message to their list too ... It would 
reduce complexity in my filesystem setup.

> > > There've even been people using RAID1 root devices over NBD. There's a
> > > link to that on the NBD home page.

Their client seems to have a multiple connection (port) feature. Their 
examples just go onto one single server, but I'm curious if I could point 
it for two different servers who sync a common partition via network
blockdevice raid1.

Have a nice sunday! Dirk