Re: [SAGE] JAILS (Re: Respondents needed for article on sysadminsurvival)

[Thornton Prime <thornton@yoyoweb.com>]

Philip Brown wrote:
> are you saying that with VMware, you can PERMENANTLY 'clone' an existing
> instance, and then maintain the two completely separately from that point?

Absolutely. Not only can you clone your operating system, binaries, disk 
partitions, and hardware configurations (down to the BIOS settings), you 
can suspend and clone a RUNNING system -- you can clone the complete 
system state including what is in RAM.

As someone else mentioned, you can also take system snapshots of a 
running system, then set up an undo log so you can later roll the system 
back to your snapshot. This is great when you are trying to identify the 
exact point of failure in a system.

Does anyone know if the VMWare "undoable" configurations can share a 
common set of initial state files? UML lets you do it with the 
copy-on-write option, so you can provision out a new instance off a 
shared configuration instantaneously. (I guess you could do the same 
thing with a jail if your jail was running on some sort of an overlay 
filesystem.)

p.s. At USENIX'03 there were a few good talks on using VMWare or other 
"container" technologies for configuration management and system 
instance provisioning. Lots of good ideas in there.

thornton