Technical considerations aside, there are business reasons that could contribute to this decision. Aside from the issues of switching processor vendors, there's also the issue of production capacity.
Intel is a much larger company than AMD. I was under the impression that AMD doesn't (yet) have the production capacity to match Intel - could they actually manage to supply at the rate Dell might require? It's not in Dell's interests to go with a component it can't obtain in sufficient bulk, regardless of technical issues.
It's true it's an Object Releational DB - PostgreSQL is a hybrid of Relational and Object database features.
I've not looked in detail into the Object database features. I believe they are more closely aligned with object orientation-type concepts, in contrast to the relational model's set-theoretic background.
How good having objects in a database actually is would probably be hotly contested by some but PostgreSQL's relational features is very good in itself (you don't have to think about objects if it doesn't suit you).
This link (nb. I took it from another post on this article) also mentions it:
http://www.linux-mag.com/2004-10/xen_01.html/
It's also (briefly) covered in the Xen 2.0 user manual. There's a research paper covering the technical details but it's not publically available yet so there isn't a link I can give you.
I can't imagine a PostgreSQL server or other complex software with shared memory, locks, etc moving anywhere while running.
That is a problem of process migration but because Xen migrates whole virtual machines, the shared memory and the locks move with the process.
The live migration was benchmarked migrating Apache server VMs whilst running SpecWeb against them and with migration of Quake 3 servers whilst running multiplayer games.
Of course, you have to arrange for the / filesystem device to be available at both the source and destination machines for the migration (e.g. use a network filesystem or network block device, or a SAN).
Support for running on Xen 2.0 is likely to be integrated into the 2.6 kernel in the near future. Support for running 2.4 on Xen 2.0 will remain a separate patch.
Xen support is planned to be checked into the mainline FreeBSD tree. Support for Xen 1.2 is already in the NetBSD mainline but for Xen 2.0, you need the patches that come with the Xen distribution.
I wouldn't bother with the 1.2 demo CD - 2.0 is a massive leap over 2.0. Unfortunately there's not an existing CD for 2.0 but it's quite simple to install on your hard drive.
There's not a demo CD for 2.0. It's simple to set up 2.0 on an existing Linux install and start testing virtual machines.
There is a user developing a new, improved LiveCD, which may be distributed in future.
Presumably Xen isn't quite as secure as VM and this work will fix that.
It's not a case of security in the conventional sense (exploits, etc.). The enhancements are specifically to allow complex Mandatory Access Controls (SELinux style), which Xen itself doesn't currently support (although you can run SELinux in Xen VMs, there's nothing that works on a whole-machine level.
In addition to other posted comments, Xen can also perform live migration (move running virtual machines to another host without stopping them) and can run Linux device drivers in sandboxed, restartable domains.
Yes, I remember that - I think it was stashed under the Help menu of Program Manager.
For beginners who had never used a mouse / GUI before it just provided a quick runthrough of the basics - actually kinda helpful when you introduce someone to a computer.
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Technical considerations aside, there are business reasons that could contribute to this decision. Aside from the issues of switching processor vendors, there's also the issue of production capacity.
Intel is a much larger company than AMD. I was under the impression that AMD doesn't (yet) have the production capacity to match Intel - could they actually manage to supply at the rate Dell might require? It's not in Dell's interests to go with a component it can't obtain in sufficient bulk, regardless of technical issues.
It's true it's an Object Releational DB - PostgreSQL is a hybrid of Relational and Object database features.
I've not looked in detail into the Object database features. I believe they are more closely aligned with object orientation-type concepts, in contrast to the relational model's set-theoretic background.
How good having objects in a database actually is would probably be hotly contested by some but PostgreSQL's relational features is very good in itself (you don't have to think about objects if it doesn't suit you).
It's also (briefly) covered in the Xen 2.0 user manual. There's a research paper covering the technical details but it's not publically available yet so there isn't a link I can give you.
That is a problem of process migration but because Xen migrates whole virtual machines, the shared memory and the locks move with the process. The live migration was benchmarked migrating Apache server VMs whilst running SpecWeb against them and with migration of Quake 3 servers whilst running multiplayer games.Of course, you have to arrange for the / filesystem device to be available at both the source and destination machines for the migration (e.g. use a network filesystem or network block device, or a SAN).
Support for running on Xen 2.0 is likely to be integrated into the 2.6 kernel in the near future. Support for running 2.4 on Xen 2.0 will remain a separate patch.
Xen support is planned to be checked into the mainline FreeBSD tree. Support for Xen 1.2 is already in the NetBSD mainline but for Xen 2.0, you need the patches that come with the Xen distribution.
I wouldn't bother with the 1.2 demo CD - 2.0 is a massive leap over 2.0. Unfortunately there's not an existing CD for 2.0 but it's quite simple to install on your hard drive.
There's not a demo CD for 2.0. It's simple to set up 2.0 on an existing Linux install and start testing virtual machines. There is a user developing a new, improved LiveCD, which may be distributed in future.
In addition to other posted comments, Xen can also perform live migration (move running virtual machines to another host without stopping them) and can run Linux device drivers in sandboxed, restartable domains.
Yes, I remember that - I think it was stashed under the Help menu of Program Manager. For beginners who had never used a mouse / GUI before it just provided a quick runthrough of the basics - actually kinda helpful when you introduce someone to a computer.