Jails vs. Zones vs. Xen

By James Dickens

http://uadmin.blogspot.com

Modified June 16, 2005



I have currently just answered the current questions for Xen no other changes have been made. But i should add more in the future. Some possibility include “Scales to more than 128” containers.


Solaris Zones

FreeBSD Jails

Xen

User Mode Linux

VMware

Why is the question important

Independent File system

Yes if needed

Yes

Yes

Yes

Yes

Uses more Space, but provides more flexibility

Shared read-only immutable Filed System

Yes

Yes, requires complex scripts, or mounting via NFS.

One user says yes, but not confirmed

Yes, May not notice changes on the underlying file system when changed by the host

Yes

Saves space and is more secure easier to maintain

Can access raw devices

No, requires permission from the host

No

Yes

File systems yes hardware no drivers are in the work but is raw hardware access a good thing.

Yes

Security Problem, but can be a requirement of the task

Access Network resources

Yes

Yes

Yes

Yes

Yes

Required in most tasks

Can create or change Network Devices

No

No

Yes

No hardware devices internally. Virtual devices, devices are more limited.

Yes

Security Risk

Can access hardware devices with out permission

No by default, permission can be granted if needed

No

No

No

No

Security Risk

Single Point of Maintenance

(kernel and software changes)

Yes

No

No

No

No

Makes Maintaining a breeze

Can send signals and kill processes outside of the zone/jail you are in.

No

No

No

No

No

Security Risk

Run’s a separate kernel

No

No

Yes

Yes

Yes

Allows for flexibility more secure.

Can monitor Processes and IO using standard tools

Yes

Yes

No

Limited with use of Uml_mconsole, tools are lacking to automate this

No


Light weight uses less than 1% CPU overhead

Yes

Yes

No, upto 8% on some workloads

No

No


Can be a NFS server

No

Maybe, requires extra configuration

Yes

Yes

Yes


Host can examine data inside the zone/choot/or UML instance without special tools


Yes

Yes

No

No

No


Resource Control outside of the Secure Area

Yes

No

Yes, but limited


Limited

Keep a run away or rogue process from stealing all resources

Simple control interface

Yes

Startup yes, shut down no

No

Yes

Yes

Easy Administration

Configuration Application for simple setup and modification

Yes

No

No

No

Yes, user must still configure host OS.

Easy Administration





Freebsd Jail Resources:

http://www.awprofessional.com/articles/article.asp?p=366888&seqNum=9&rl=1

Xen Resources:

http://www.cl.cam.ac.uk/Research/SRG/netos/xen/performance.html

http://www.xensource.com/files/xensource_wp.pdf