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Did you ever progress with SSDs?
We are also now interested in using SSDs with OVM servers, as we've had issues booting them off USB media.
I was going to go with an 8GB SSD, and use the USB minimal layout install method - does anyone know if this actually works with a 'normal' HDD, or is it only for USB media?
Also - is the USB install different from the standard install, with regards to the actual packages that are installed, perhaps there is no local logging, which might cause issue with restricted space flash media?
There is no description in the documentation about exactly what this minimal install is.... aside from having a cut down layout.
I've played around with the installing on a USB flash drive. Just a little. Haven't spent much time on it. It does work.
We have done quite a few on USB flash drive - it works, however, we suspect only for a certain period of time (6 months) - you run into problems. We've had a few failures, and we've been using different media etc. I think it's a combination of heat / too many writes even. I would really like to know if the USB install has been specially adapted to reduce the amount of writes or not (disabling logging or logging to ramdrive etc.)
Hence we are now looking at alternatives.....
I was really interested to know about Roddys SSD test - but actually, there are quite affordable 60GB SSDs now, so I think we will just use these from now on and use the 'standard' partition layout.
In short, the customer is still in production with the 4G SSD hard drives, its stable. We benchmarked the dom0's and the domU on the HP G8's with the 4G SSD hard drives (pool a) against HP G8s with 140G local hard disks (pool b), and the numbers were very close, albeit, in general not quick, i.e. ~40% slower than their ESX servers (with the same 4G SSDs) and VMs on the same gear.
So you are saying that OVM is 40% slower than the same DOMU running on ESXi?
All of my customer run ESX, so when we benchmark OVM we also benchmark ESX. Typically on the same hardware, network and storage infra.
On the project with the SSD drives, ESX was faster. That being said, please note that the customer was running ESX for over 4 years, and had tuned the SAN, network and VMs for ESX, not OVM. The customer was 100% new to OVM, i.e. only two weeks of OVM experience in contrast to 4 years of ESX experience. I was only on the project for 2 weeks, with ONLY one day allocated for tuning. If the customer had the budget, we would have allocated two weeks to tune and would have improved the OVM numbers.
There are MANY great free benchmark tools, i.e. like Oracle's Orion, that you can use to benchmark your systems to better understand the performance and to help tune for speed.
The ONLY way to know is to benchmark! Stay tuned to my web site and book, the oracle cloud cookbook, for LOTS of OVM benchmaking information and real benchmark results.
Thanks Roddy - I guess it does depend on the mix of hardware and like you said, the customers prior experience with OVM. I guess they would have had a bit of a shock in moving.
I have moved a number of servers now from ESXi to OVM and have to say, I have not seen a dramatic increase or decrease in performance - I'd say it was about the same.
I do have a sneaking suspicion though that there is quite a bit more performance to get out of the platform specifically for VMs running Windows server.
There does seem to be an apparent lack of clarity from Oracle with regards to Windows server support on OVM. The current PV drivers are still 3.01 and have not been updated for years. Now that 2012 is out, there is still no sign of any official support, although I see people have been able to install them (with errors) and they apparently work - though I would like to make a bet they would be completely unsupported by Oracle.
Many of my customers would like to settle on a single VM platform. Some might have 80% Linux and 20% Windows. Some might have 50% / 50%. The fact is that most environments I see have some component running Windows at least and as such, customers would like to have everything on the one platform. Being free and very cost effective to support is a great plus. There is real momentum now in that 3.1 was actually usable for production environments, and 3.2 is fast getting there also.
So this would be an ideal time for Oracle to release updated Windows PV drivers, with further optimised performance for Windows 2008R2 and Windows 2012.
The continued silence on the matter is highly annoying - and somewhat of a worry.
Thank you for your detailed reply!
The Oracle team that supports Oracle VM are Oracle's Linux team. That might explain the lack of Windows enthusiasm.
The one hypervisor conversation is a fun one indeed, its just like the one OS conversation. One OS is as unlikely as one hypervisor. MS, Red Hat, Citrix, Oracle, IBM, HP, Open Source and sales reps will keep our customers data centers full of various OSs and hypervisors for the foreseeable future.
Have you had a chance to shakedown the new Oracle VM/Linux Guest Additions? http://docs.oracle.com/cd/E35328_01/E35333/html/vmutl-guestadd-install.html