Re: Linux on IBM Power5s

<G> Reading some of my grammatical atrocities I think I'm getting a little too
geeked out. ;-) And here comes more caffeine....

On Wed, 6 Jul 2005, Arthur Corliss wrote:

> Greetings:
>
> Just thought I'd throw a few ideas out there, now that I've had some decent
> playing time with Linux on IBM's Power5 (in a p5 570). In a nutshell, it's
> awesome, and if IBM can simply get the commercial software vendors to support
> Linux PPC they'd blow the doors off the blade market.
>
> You can micropartition you can create host partitions with as little as 1/10th
> of a processor, giving you a total of 40 partitions you can host in a single
> 4-way CEC. Throw in a virtual I/O server partition (basically just a
> specialised AIX install) and it becomes practical to do so since you can now
> put all of your system disks, etc., on an external SAN *without* having to
> have a dedicate FC HBA on each Linux partition. The hosts think they're
> talking to locallly attached SCSI DASD via a virtual SCSI card (supported in
> the 2.6 kernel).
>
> 2.6 also adds support for virtual NICs, and so you can aggregate your local
> traffic over one (or multiple, using LACP) physical ports hosted by a VIO
> partition. The hypervisor provides full layer-2 switching capabilities with
> 802.1Q support, with about 3Gbps total throughput.
>
> Then, look at the processors: starting with the Power4s you had two full CPU
> cores on a single die. The Power5s add a psuedo-hyperthreading capability to
> each core, so with SMT + SMP on one processor gives you an effective four CPUs
> capacity (depending on your actual workload).
>
> How about DLPAR: want to add processors, memory, I/O cards to a partition?
> You don't even have to interrupt the running host OS.
>
> Barring IBM hiring all of DECs old marketing people I can't see how these type
> of capabilities won't wipe the floor with blade servers. Why waste an entire
> blade to sit idle running DNS, or lose the attached disk space? Give it a
> tenth of a processor, and carve an LV from a LUN managed by the VIO server's
> LVM that's no bigger than you really need. Getting hit a little hard? Throw
> another tenth of a processor on the fly, then take it back when the system
> load drops.
>
> Imagine a fully loaded 570 w/4 4-way CECs: in 18U or rack space (4U/CEC plus
> 1U/ea for the HMC & console) you can have up to 160 partitions managed as one
> seempless pool of processor, memory, and I/O that you can allocate as you see
> fit. Well, you do need to add at least another 7U for the SAN, but hey,
> that's still less than half a rack, and more cost-effective than a blade
> server to get the same level of redundancy without any of the flexibility.
>
> Of course, this did force me to move to the 2.6 kernel for my ppc port of
> Nevaeh Linux, so it's not all roses. If we're lucky Linus will fork a 2.7
> branch so 2.6 can really stabilise.
>
> BTW, you can run Red Hat and SuSE on the 570, so some of your favourite
> distros are available for it. I did try SuSE on it for about a week, but I
> had to stop when I broke out in hives. ;-) And from I've read Red Hat really
> screws you on the licensing (you have license even a .1 processor partition as
> an 8-way machine, any partition with more than 8 processors requires a 16-way
> license. So, in my current configuration I'd have to license my 4-way CEC for
> 112 processors :-P To SuSE's credit I only have to license the number of
> physical processors).
>
> --Arthur Corliss
> Bolverk's Lair -- http://arthur.corlissfamily.org/
> Digital Mages -- http://www.digitalmages.com/
> "Live Free or Die, the Only Way to Live" -- NH State Motto
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        --Arthur Corliss
          Bolverk's Lair -- http://arthur.corlissfamily.org/
          Digital Mages -- http://www.digitalmages.com/
          "Live Free or Die, the Only Way to Live" -- NH State Motto
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To unsubscribe, send email to <aklug-request@aklug.org>
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Received on Wed Jul 6 09:24:11 2005