This discussion really boils down to the difference between full-virtualization and para-virtualization.
Do a google search for "full virtualization vs. paravirtualization". One of the things you will learn is that VMWare is full virtualization and Xen is para-virtualization. Para virtualization exposes parts of the underlying hardware allowing the guest OS direct access to some things, chief among them hardware clocks and timing which is absolutely critical to Asterisk. Asterisk running on a fully virtualized guest OS is unlikely to run properly because the clock bounces all over the place. Even just keeping the proper date and time is problematic on these systems which is why you are supposed to install "VMWare tools" which helps mitigate these issues. On the other hand, my understanding is that Asterisk on Xen runs great. I believe there is even a commercial product for hosted PBXes that is based on this though the name escapes me at the moment. And there Xen kernel modules for Digium cards meaning you install the Digium cards in the Xen box and then all the virtual machines can access them just as if they were installed on the local system. A couple more things to keep in mind: - there is a massive difference between virtualization installed on top of an existing OS (such as VirtualBox, Microsoft Virtualization and all the "free" VMWare products), and "bare metal" virtualization like ESX and Xen. Bare metal is the only way to go for serious virtualization. - There are now specially tuned installs of some OSes designed for virtualization. For example, SUSE has an option for "this is a virtualized system" which installs all the specially tuned kernel options which makes a major performance difference. - And, everything I've said above, while still true, is a bit outdated. VMWare has recently gotten into the para virtualization game and there has been _tons_ of work done on the linux kernel in the last couple years to improve the performance of full and para virtulized systems. -- John Lange http://www.johnlange.ca On Thu, 2010-03-04 at 00:49 -0500, Reza - Asterisk Consultant wrote: > *Hey guys!* > > Thanks for all your responses. We've played heavily with ESXi -- but > before getting an Asterisk server with ESXi, I'm not ready to take a blind > leap of faith here without bench marks. I don't mind swimming in a cold > water if I know there are others with me :). But then again if there are > other options besides ESXi catered for Asterisk, then I'd liketo investigate > it. > > During peak hours - we can hit 70+ simultaneous calls on ONE server alone. > We've also been receiving lots of requests for Virtual Asterisk Hosting > needs (plain vanilla Asterisk & FreePBX type). So I need to keep an open > mind with Virtualization options for prospects & clients. > > *Robert: *If you are using software G729 transcoding - then forget ESXi. > If you are doing any form of transcoding, then forget ESXi. If you are > doing call recordings & some sort of transcoding, forget ESXi. If you are > running Asterisk on top of other VM's on the same ESX(i), that is running > Windows Servers, Application servers and ESX(i) - then forget it. > > IF you **must** use PRIs in a virtual environment, then use foneBRIDGE ( > http://www.red-fone.com/) and make sure there is no transcoding going on. > > > *Hey Dave: *Been a LONG while! As per XEN, I've never used it - but I've > also heavily used Virtual Box. Though I love Sun's Virtual Box compared to > VMWare Workstation - don't even think of deploying Asterisk on VirtualBox on > a production platform. Trust me, as you always have :). > > *Cheers! > Reza.* > > -- > Toronto based VoIP / Asterisk Trainer, > I.T. Consultant and Hosted PBX Solutions Provider. > +1-647-476-2067. > http://www.linkedin.com/in/seminar > > > On Wed, Mar 3, 2010 at 9:57 PM, Robert Brock <[email protected]> wrote: > > > Odd, I had a lot of problems with ESXi. > > > > If I setup the asterisk server with just a firewall and asterisk server > > everything ran fine, Isolated nics for each app and network (internal, DMZ > > and external), worked fine, but as soon as you load more VM machines things > > started to go sideways. Call quality of recordings went weird, G729 > > connections started to act like there was a lot of jitter on the line. > > > > I tried loading a test server on our ESX cluster and it was much much worse > > (60+ VM's). > > > > Also with ESXi you can't add PRI/PSTN cards, everything must be external. > > > > I couldn't see much point in running a production asterisk server as and VM > > on ESX - Handy for testing but not for production. > > > > I have also tried using ESX as a media server for Video and once more than > > 6 Vm were running on the ESX cluster video would get choppy for 1080P > > streams, it's like the network resource pools are being shared, even when > > nics are isolated to the specific VM. > > > > Robert Brock > > Telecom Administrator, MKS Inc., www.mks.com > > Waterloo, ON, Canada > > Tel: 519-883-3243 or 800-265-2797 x3243 > > Fax: 519-884-8861 > > > > > > -----Original Message----- > > From: Dave Donovan [mailto:[email protected]] > > Sent: Wednesday, March 03, 2010 9:27 PM > > To: Asterisk Users Group > > Subject: Re: [on-asterisk] VM ESXi on Asterisk Production Platforms. > > > > On Wed, Mar 3, 2010 at 3:34 AM, Reza - Asterisk Consultant > > <[email protected]> wrote: > > > Has anyone in here worked hands on with ESXi and Asterisk? Would like > > to > > > hear your input and benchmarks, along with recommendations of other > > > alternatives that you may have placed at your data centre running > > Asterisk. > > > > > > Do you prefer ESXi or other alternatives? If alternatives, then why? > > > > Reza, > > > > This is a timely post. We just deployed Asterisk (PBX in a Flash) on > > our ESX 3.5 platform at our Mississauga office. ESXi is just a > > skinnier version of ESX. > > > > It's a bit early to say much about long-term stability, but we've had > > no problems with Asterisk since deployment. Fingers-crossed. > > > > During testing, we found we had choppy/poor quality audio on > > playback() operations like autoattendant. It wasn't as bad with > > voicemail messages so we installed native sounds, hoping that avoiding > > GSM-ULAW transcoding would fix it. It was improved but not great. We > > applie a kernel patch to resolve timing issues that caused the choppy > > audio. Now it's smooth as silk. > > > > Info on that patch can be found here: http://pbxinaflash.com/vm/ > > > > We ran the code exactly as it appears near the bottom of the page. > > The only other thing we had to do was edit grub.conf to make the new > > kernel the default one. > > > > I imagine that you're looking at a hosted type of application so, > > unfortunately, I can't tell you much about scaling since we're running > > only one Asterisk instance and it's the only thing in the high > > priority resource pool. It doesn't have to contend with any > > resource-intensive guests on the same machine. > > > > We chose VMware a couple of years ago for several reasons not related > > to Asterisk. Since then I've heard good things about other platforms > > like VirtualBox and Xen but I have no first hand experience with them. > > > > Good luck with your project, > > > > Dave > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [email protected] > > For additional commands, e-mail: [email protected] > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [email protected] > > For additional commands, e-mail: [email protected] > > > > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
