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Dynamic Logical Partitioning for Linux on POWER
An anonymous reader writes "Logical partitioning provides POWER processor-based servers with the capability to do server consolidation and optimize system resources. Dynamic logical partitioning enhances this capability by providing control of the allocation of the resources without impacting the logical partitions availability. Linux on POWER supports dynamic LPAR for changes to physical I/O, virtual I/O, and processor resources."
This has been available from IBM for years. I've only started with POWER 4 but I think it was available a few versions back as well with limited functionality on Linux. The more advanced features recently came available with the release of the POWER 5 processor. Nearly all of the RAS features are now available for Linux on IBM that have been available for AIX.
They also support Redhat and SuSE. Good stuff!
And for once I drool over something I have only vaguely an idea of what it does.
What it does is allow reconfiguration of system resources, such as IO cards, memory or cpu's (or on Power 5 with AIX 5.3, portions of a cpu), etc. on the fly without having to reboot your server to acknowledge them. AIX has had this capability since 5.2.
It's great for being able to juggle your resources on the fly, but it really comes in handy for moving your DVD drive between partitions on a frame without having to reboot. Having to reboot 2 servers just for that is a royal PITA.
You know, that's pretty much exactly what I thought when I saw this 'article'. I suppose IBM's LPAR technology on Power is useful, cool tech. But this seems more like a press release than 'news'. This stuff has been around for a few years now (granted, a lot of folks still haven't heard of it, so I suppose in a way it's 'news' to them).
But, this seems a lot more like an advertisement for IBM than 'news'.
Simultaneous Multi Threading is an even cooler feature of the POWER 5 chip!
Here's a pdf.
In the future, I would want to not be isolated from my friends in the Space Station.
If you want a better idea of how LPARs are setup on POWER5 hardware check out episode 5 of The Packet Sniffers. They show a 570 system and some brief menu's of the HMC console one uses for LPAR resource management and DLPAR. Not exactly DLPAR on Linux, but the process is the same for Linux as AIX. If you are curious how this works then check it out.
http://www.packetsniffers.org/
Nice write up from IBM, but it's important to remember thaat the Linux kernel only supports dynamic changes in CPU and PCI devices, you can't move memory around. AIX allows dynamic memory; the Linux kernel will need some fundamental chages to enable this. Power5 is indeed the coolest technology around today, but Dynamic LPAR started on the Power4 back in 2001, so this is kinda old news.
-The Mad Duke
It's a pretty cool technology. We're running multiple AIX 5.3 partitions on IBM pSeries boxes. Setup of the systems are pretty easy and allocating memory/CPUs is straightforward. The only concern is that the overhead increases substantially with the number of LPARs.
The only problem I have with pSeries linux is that it somewhat negates the cost advantage of Linux on Intel. Well, make that obliterates the cost advantage. IBMs AIX is free with the hardware. Linux is licensed per instance. So it's cheaper to run AIX *on pSeries* when you have many instances.
The POWER series has this on-chip, so it's a whole lot faster than doing it via software and it doesn't require a reboot. The dynamic partitioning is the real difference between the POWER series and the PowerPC chips IBM sold to Apple. This is a feature carried over from IBM's mainframe days, and if you actually need it, it is very cool.