# questions about jails and compatability issues



## maudib (Feb 3, 2012)

Hi,

Is it better, to avoid headaches later on, to just stick to the same update/upgrade method on both the host system and a virtual "jailed" system, in one of the host system's directories? I.e if you maintain the host with freebsd-update would it be a bad idea to maintain a virual jailed system using the source/CVSup for that release? Or do the two methods remain in sync enough for this to work? Ideally *I* would have liked to use CVSup or csup to maintain the host but due to having a limited amount of time this wasn't possible, and *I*'m trying to avoid a re-install.

Thanks for any replies.


----------



## maudib (Feb 3, 2012)

Sorry, *I* know you have to rebuild jails if you want to upgrade them. However two questions still remain. They are:

1) How do you make sure that your kernel is compatable with the "world" installed in the jail?
2) Can you maintain a jail from source on a host that uses freebsd-update to stay up to date with the release branch?

Thank you very much for any replies.


----------



## maudib (Feb 3, 2012)

erm really sorry the answers are in the handbook. Sorry if i've wasted anyones time
regard


----------



## UNIXgod (Feb 3, 2012)

maudib said:
			
		

> erm really sorry the answers are in the handbook. Sorry if i've wasted anyones time
> regard



Not really a waste. I'll post the relevant section of the handbook for people who may have the same kind of question as you.

16.6 Application of Jails



			
				maudib said:
			
		

> 1) How do you make sure that your kernel is compatable with the "world" installed in the jail?



The kernel and jail world must coordinate. This limitation is due to the fact that FreeBSD is an actual complete OS vs strung together distro. Also jails are a low level virtualisation and works on the kernel level unlike vmware/xen which emulate hardware. Every time you update your FreeBSD install to the next incremental version you will have to update your jails as well. Ports should not require recompile unless you jump from actual releases (i.e. 8.x -> 9.x)


----------



## vand777 (Feb 4, 2012)

UNIXgod said:
			
		

> Not really a waste. I'll post the relevant section of the handbook for people who may have the same kind of question as you.
> 
> 16.6 Application of Jails



Some time ago I was creating and maintaining jails as described in this link. However, it is quite time-consuming approach. I switched to sysutils/ezjail - never regreted so far. Ezjail documentation.

People also recommend sysutils/qjail.


----------



## gkontos (Feb 4, 2012)

vand777 said:
			
		

> Some time ago I was creating and maintaining jails as described in this link. However, it is quite time-consuming approach. I switched to sysutils/ezjail - never regreted so far. Ezjail documentation.
> 
> People also recommend sysutils/qjail.



Same here. I used to maintain handmade jails but I have switched now to sysutils/ezjail. A utility is always useful when you have to maintain and upgrade 10+ jails.


----------

