From: antfio@MUZE.COM
Date: Wed Aug 21 2002 - 12:06:37 EDT
Excellent info, Bill. Thanks. We're looking at a 670 ourselves and I
couldn't find that info anywhere, yet.
I did find a redbook on the 690 today which I have yet to read. It's the
"System Handbook" for the 690. Since the 690 and 670 are almost identical in
nature, this seems like a good read.
-Anthony
> -----Original Message-----
> From: Bill Verzal [mailto:Bill_Verzal@BCBSIL.COM]
> Sent: Wednesday, August 21, 2002 12:01 PM
> To: aix-l@Princeton.EDU
> Subject: Re: p670 availability
>
>
> I/O drawers are not hot-pluggable. PCI cards not
> "hot-swappable" cannot be
> hot-swapped, even though the Regatta supports it.
> Microcode requires a complete outage. CPU and memory of
> course do as well.
> Hot-swappable cards can be changed out on the fly, but each
> one requires
> 25-minutes CE time due to the number of "mounting screws" on
> the carrier.
>
> Also, here are some more issues I raised related to these
> questions, along
> with the answers I received. I had some questions on
> statements that were
> made in the sales manual.
>
> BV
>
> First:
>
> A minimum of 4 GB of system memory is recommended per LPAR.
>
> Can you clarify this statement ? Why is it "recommended?"
>
> This is only a recommendation, depending the
> environment 1 or 2 GB
> of memory minimum per LPAR might do the job. This
> recommendation
> will allow for optimal performance with a minimum
> configured LPAR
> for the average environment. This will allow for
> applications to
> utilize 2 to 3 GB of memory while leaving enough
> memory for the
> Hypervisor and AIX. On average, most applications
> will size 2 - 3
> GB of memory per CPU. This is just an average, some
> applications
> may require more or less that the 2 - 3 GB average.
> For example,
> some web base or routing applications requires only 1
> - 1 1/2 GB of
> memory per CPU, in this case you will size your total
> memory for 2
> - 3 GB of memory per CPU. Another example, some Databases can
> utilize 2 - 4 GB of memory per CPU, in this case you
> would size
> your memory for 3 - 5 GB of memory per CPU. If you are running
> multiple applications in the same LPAR or same OS
> image then your
> memory requirements will be greater. It is
> recommended to allocate
> 1/2 GB to 1 GB of memory for AIX and the Hypervisor.
> The memory is
> configured in whole numbers, so as a rule of thumb
> you size the
> memory at lease a Gigabyte or more higher than what
> the application
> requires
>
> Second:
>
>
> Minimum of two internal SCSI hard disks are required per
> p690 server.
> It is recommended that these disks be utilized as mirrored boot
> devices. These disks should be mounted in the first 7040-61D I/O
> drawer. This configuration provides service personnel the maximum
> amount of diagnostic information if the system
> encounters errors in
> the boot sequence.
>
> What does this mean ?
>
> This configuration will allow you to minimize your
> system downtime
> due to a disk Drive failure or service work on an I/O drawer.
>
> Boot support is also available from local SCSI, SSA, and
> Fibre Channel
> adapters, or from networks via ENET or token-ring adapters. The
> pSeries 690 does not support booting from FDDI adapters
> #2741 or #2742
> located in 7040-61D I/O drawers.
>
> No questions there...
>
> Consideration should also be given to the placement of AIX rootvg
> volume group in the first I/O drawer. This allows AIX to
> boot any time
> other I/O drawers are found offline during boot.
>
> Why would an I/O drawer be offline, and what are
> scenario's that this
> might affect us on ?
>
> The key reason for an I/O drawer to be offline is for
> maintenance
> or repair.
>
> If the boot source other than internal disk is configured, the
> supporting adapter should also be in the first I/O drawer.
>
> What does this mean ?
>
> The p690 will provide a very highly available
> environment without
> HACMP, but depending on how a p690 is configured the
> availability
> of a system may drop. To minimize downtime due to a
> single failure
> you should spread your dependencies across the I/O
> subsystem as
> much as possible. Dependencies are things like rootvg
> disk drives,
> network adapters, and adapters used to access disk
> drives (Fibre
> Channel, SSA, and SCSI). The first I/O drawer is the
> first drawer
> to come online or have power applied. There is a
> remote chance that
> a problem in one I/O drawer can affect I/O drawers
> downstream. A
> problem could be disconnecting downstream cables for
> maintenance or
> service. Let's say you configured all of the I/O
> resources (rootvg
> Disk Drives, Ethernet adapters, Fibre Channel
> adapters, etc.) for
> LPAR #1 in the first half of drawer #3. Your single point of
> failure in this case would be any failure that would
> affect the
> first planer board in drawer #3, and would cause LPAR #1 to go
> down. If on the other hand, half of the I/O resources
> was spread
> across two different drawers (drawer 1 and 3) then
> you can pull
> things like RIO or power cables and LPAR # 1 will not go down.
>
>
> --------------------------------------------------------------
> ---------------------------------------------
>
> Bill Verzal
> Technical Consultant
> Forbes Technical Consulting
> (312) 653-3684
> bill_verzal@bcbsil.com
> MailStop: 27.201C
>
>
>
> Holger.VanKoll@SW
> ISSCOM.COM To:
> aix-l@Princeton.EDU
> Sent by: IBM AIX cc:
> Discussion List Subject: p670
> availability
> <aix-l@Princeton.
> EDU>
>
>
> 08/21/2002 10:50
> AM
> Please respond to
> IBM AIX
> Discussion List
>
>
>
>
>
>
> Hello,
>
> I have to find out
>
> - which parts cause a scheduled downtime when they fail (not
> hot-pluggable, but redundant)
> - which parts cause a unscheduled downtime when they fail
> (not redundant)
> - which parts cause no downtime when they fail (hot-pluggable).
>
> I know I can find this out by reading a few books, but maybe
> anyone did
> this before?
>
> I am also interested in incomplete answers.
>
> Thank you and regards,
>
> Holger
>
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