I'm working with Alan on this too, and a lot of the issues revolve around the definition of "stateless" and what's expected from it.
If it's the ability to move apps between servers transparently, we already have that. Just shut down the instance, and IPL on another VM image. If it's the ability to move apps between servers without an outage, ala VMWare ESX, we don't have that (yet). If it's to save disk space by sharing the base filesystems, we're still debating that. It's up in the air whether the saving would be enough to justify heavily customizing our build and taking on the maintenance issues. "Stateless" also seems to make the most sense if you're rolling out large numbers of identical commodity servers, but we're not doing that, almost all of our servers have packages added above the base build that would affect that "shared" filesystem. Most of the "stateless" implementations I've seen seem to rely on "bind mounts", but that seems to be a bit of a hack. "Union" mounting, such as "Unionfs" look like it would be a cleaner approach, but I can't find out if there's a workable implementation of that. Any ideas? I've pulled the unionfs patch, but I'm reluctant to go to the trouble of maintaining yet another custom kernel module. -----Original Message----- From: Linux on 390 Port [mailto:[email protected]] On Behalf Of Edmund R. MacKenty Sent: Thursday, May 14, 2009 10:38 AM To: [email protected] Subject: Re: [LINUX-390] Stateless Linux for zSeries On Wednesday 13 May 2009 20:10, David Boyes wrote: >On 5/13/09 3:16 PM, "Alan Ackerman" <[email protected]> >wrote: >> Someone here says we should not do Linux on zSeries because you cannot do >> "stateless computing" on zSeries. > >In a word: bunk. > >> Has anyone had any experience with building a stateless Linux on zSeries? > >The Novell starter system is a good example. Any of our Debian deployment >tools are examples. The stuff we're doing with OpenSolaris diskless virtual >machines is an example. > >Can't do it -- pah. We (the mainframe) *invented* it. Exactly. I've read up on this buzz-phrase a bit now (great links folks! thanks!) and I can't see how "stateless computing" is much different from a z/VM guest running Linux applications and mounting its data filesystems via NFS from some network storage appliance. If there's a problem with the guest, you just configure another one and replace it. Lots of people on this list have been doing that for years, as have I. <shamless-plug>There're products around that will help you implement this (contact me off-list).</shameless-plug> So Alan, tell that "someone" that they're very wrong. - MacK. ----- Edmund R. MacKenty Software Architect Rocket Software 275 Grove Street * Newton, MA 02466-2272 * USA Tel: +1.617.614.4321 Email: [email protected] Web: www.rocketsoftware.com -------------------------------------------------------------------------- This message w/attachments (message) may be privileged, confidential or proprietary, and if you are not an intended recipient, please notify the sender, do not use or share it and delete it. Unless specifically indicated, this message is not an offer to sell or a solicitation of any investment products or other financial product or service, an official confirmation of any transaction, or an official statement of Merrill Lynch. Subject to applicable law, Merrill Lynch may monitor, review and retain e-communications (EC) traveling through its networks/systems. The laws of the country of each sender/recipient may impact the handling of EC, and EC may be archived, supervised and produced in countries other than the country in which you are located. This message cannot be guaranteed to be secure or error-free. References to "Merrill Lynch" are references to any company in the Merrill Lynch & Co., Inc. group of companies, which are wholly-owned by Bank of America Corporation. Securities and Insurance Products: * Are Not FDIC Insured * Are Not Bank Guaranteed * May Lose Value * Are Not a Bank Deposit * Are Not a Condition to Any Banking Service or Activity * Are Not Insured by Any Federal Government Agency. Attachments that are part of this E-communication may have additional important disclosures and disclaimers, which you should read. This message is subject to terms available at the following link: http://www.ml.com/e-communications_terms/. By messaging with Merrill Lynch you consent to the foregoing. -------------------------------------------------------------------------- ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
