[nycbug-talk] FreeBSD jails and custom kernels

max max
Wed Aug 31 11:12:44 EDT 2005

you are totally right, Im aware, i do setup custom userland per jail. 
Since im stoopid and keep forgetting we dont live in 80's and/or world of monolithic kernels, freebsd linux.ko totally slipped my mind : )
Thanks Mike, Pete.

On Wed, Aug 31, 2005 at 08:08:12AM -0700, pete wright wrote:
> On 8/31/05, max <max at neuropunks.org> wrote:
> > Hello,
> > I have a jail question. Can I make custom kernel per jail?
> > Basically, I need COMPAT_LINUX, but I dont feel really good about recompiling the kernel on the host itself, since its a production machine, but it has some jails that I can happily destroy if anything goes wrong.
> > I looked on google, nothing too relevant, and from jail howto's that ive seen, we always link /kernel to /dev/null and use the main host's kernel.
> > I can see why it would be pretty hard to implement, to have a full kernel instance per jail, but  im still wondering if its possible.
> > Thanks!
> > 
> No you can not make a custom kernel per jail.  You can, and often
> should, make a custom userland per jail as this run's ontop of the
> host Kernel+Userland.
> This paper provides a good background on the thoery behind the
> operation of jails in FreeBSD:
> http://docs.freebsd.org/44doc/papers/jail/jail.html
> In short, jail's are not a virtual machine they are an extension of
> the concept of chroot.
> -pete
> -- 
> ~~o0OO0o~~
> Pete Wright
> www.nycbug.org
> NYC's *BSD User Group

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