Virtualization and ASE
March 26, 2007 1:34 PM
Filed Under: Adaptive Server Enterprise (ASE) Linux Virtualization
Virtualization (at the operating system level) seems to be quite the rage today ... more and more customers that I visit are talking about it, but I'm wondering, how many of you are actively using it, or are planning to deploy it on Linux (and run Sybase underneath)?
I've followed with interest the progress of both paravirtualization and hypervisors on the Linux platform for quite some time now -- in fact I've been running VMWare workstation since it was pre-v1.0 (back on Redhat 6!!). It's a great product, and a lot of customers use it, mainly because it's a hypervisor and doesn't require any modification of the guest OS to run on the host. It's just dead simple to install and use (kudos to VMWare for putting out such an excellent product). Performance is touted to be near or equal to the guest running natively on the host's hardware, and from my experience, I've seen exactly that.
However, in the opensource world, a few years ago we started to see the beginnings of paravirtualization ... which is similar to the offerings of products like VMware but the main difference is that paravirtualization requires modifications to the 'guest' so that it can run on the host OS -- not very appealing to me since really the only OS that you can modify is Linux and even then you might be out on your own support-wise with your Linux vendor. This isn't the case anymore ... the latest Xen versions (3.0 to be exact) allow unmodified guests to run on the host under what's now being called hardware-assisted virtualization ... but I must confess I haven't really tried either out yet, and I'm not sure how stable this is, or what the performance impacts are (or will be).
Guess I'll spend some free cycles trying to find out :)
So what's the point of this blog post? Good question.
Since this is now supported in SLES10 as well as RHEL5 and 4.5, I'm curious if anyone out there is running ASE under Xen right now. Sybase doesn't officially support this to my knowledge, so that may be my answer right there, but I'm wondering if customers are looking at doing this or not. (Note that I'm not talking about running ASE under a VMware guest ... we already support that. This is specifically asking if you are looking at using Linux kernel-level virtualization). If you've implemented it, what did you notice as far as performance ... any major differences vs. running against the host? Any gotchas you wanna let me know about in the comments section before I get going? I'm going to play with this over the next few weeks, so watch the comments section here as I'll update what I find out, but I'm always open to pointers and suggestions!
-Chris
Posted by Chris Brown on March 26, 2007 1:34 PM
Comments
Sheila email -
That's a pretty deep question.
I am just happy that ASE runs in VMware so that I can use the same machine for testing, training, and demonstration without rebuilding each environment as an application moves through it's life cycle.
Chris Brown email - blogs.sybase.com/bloggers/ChrisBrown.aspx
Well, I've run into some challenges getting Xen going. I've spent the last few nights trying to get my home system upgraded to a more 'recent' Linux distribution that supports Xen and, well, that hasn't been going well :-/ Hopefully tonight I'll get things up and running ... problem is I have a troublesome RAID Card that always wants to be the primary IDE interface and well, GRUB don't like that one bit ... hopefully by the end of the week I'll have Xen up and going and my first Xen-based VM working ....
Jason L. Froebe email - www.froebe.net/blog
Running ASE, ASIQ, or SQL Anywhere under virtualization software such as Xen, VMWare, Parallels, etc is very useful under a number of situations:
1) development of new applications - each developer group can have its own "db server" on the same machine
2) testing new ebfs/releases with your applications
3) reproducing problems either in the sybase software or in the application code - a 'virgin' instance that can be duplicated at will
4) trying out new operating systems (moving from Windows to Linux or Windows to Solaris x86?) without investing in new hardware
The main caveat is that the performance stinks - databases typically require high disk i/o, memory i/o and cpu responsiveness. The virtualization software currently available, even with hardware help (newer Intel,AMD chips), are not up to the task of running a *production* database.
Chris Brown email - blogs.sybase.com/bloggers/ChrisBrown.aspx
Sorry I'm a bit lax in carrying on with this; I had a family emergency that threw this onto the back burner for a few days. But, after all that work of rebuilding the home machine (and lots more reading of FAQ's and wiki's) I've come to find out that my home machine doesn't support kvm (which, from everything that I've read, is what I want to use for virtualization if I'm going the opensource route). The chip is just too old ... man I didn't think a 64-bit chip would be "obsolete" after just a year and a half. But I can still try Xen, so I'll do that ... I've got 1/2 TB RAID-0 sitting at home that I can play with, so we'll run some basic comparisons on speed and performance (native vs virtualized)
My laptop *does* support kvm however, and the benchmark numbers that I have read look pretty good, but it's in its infancy [having only been rolled into kernel 2.6.20 "officially"]. As Jason pointed out, there are some issues with I/O since the hardware components are virtualized as well, adding a separate layer, but the question that I want to answer really is what is the performance hit that we're taking here (50? 70? 10?) because, again, I get asked about this from time to time (and did in fact today). Stay tuned.
