Solaris features in FreeBSD

[Andriy Gapon]

on 03/06/2012 17:56 Bryan Drewery said the following:
> 
> 
> On 5/31/2012 3:45 PM, Chris Nehren wrote:
>> On Thu, May 31, 2012 at 17:20:04 +0200 , Oliver Fromme wrote: And
>> speaking of Solaris features...
> 
>> On Thu, May 31, 2012 at 19:13:32 +0100 , Matthew Seaman wrote:
>>> This sort of operation is something that ZFS boot environment support 
>>> (recently committed to HEAD, due for MFC within the month) makes much, 
>>> much safer and easier to deal with.  You don't need to do a separate 
>>> reboot to test the kernel as you've still got an entire kernel+world
>>> in the previous BE to fall back on.
> 
>> This is *awesome*. /me removes yet another item from the "reasons to use 
>> Solaris" list. I cannot wait to try this out.
> 
> 
> ZFS Boot Environments are supported even without the HEAD changes.
> 
> Some ports/scripts to assist:
> 
> beadm Solaris-like script: sysutils/beadm (see
> http://forums.freebsd.org/showthread.php?t=31662)
> 
> Another: manageBE
> (http://anonsvn.h3q.com/projects/freebsd-patches/wiki/manageBE)

Let's avoid confusion here.

These tool do all the hard parts of the boot environments concept - create
them, manage them, destroy them, etc.
But, if I am not mistaken, the tools don't deal with the essential aspect of
boot environment - choosing which environment to boot.  And I think that this
is one of the main points of _boot_ environments.  That is, the tools are very
useful and convenient until a day when you create a new environment, populate
it, activate it and then reboot to it only to discover that the boot fails at
some very early stage (e.g. during kernel boot).  At this point you would have
to use some alternative boot method (like a boot CD) to switch back to any of
the known good boot environments.

The changes in head should help with selection of BE at boot time at loader or
even zfsboot stage.  Thus, the recovery should no longer require alternative
boot methods.

-- 
Andriy Gapon