LPAR IBM pSeries 650
Vikram Sharma
650 Server.
Below is the hardware specification:
--------------------------------------
Rack Server pSeries 650: 1 Qty
36.4 GB 10,000 RPM Ultra320 SCSI Disk Drive Assembly: 2 Qty
146.8 GB 10,000 RPM Ultra320 SCSI Disk Drive Assembly: 2 Qty
2-Way 1.2 GHz POWER4+ Processor Card: 4 Qty
4096MB (4*1024MB) SDRAM DIMM Memory: 4 Qty
Wondering how many LPAR's I can do with the given configuration,
reason I am asking is because one of our Sys. Admin's told us that we
can only do 2 Partitions, because the pair of each disk drives are
mirrored together.
If this is true is there a way we can split these drives. We will be
using this server for dev., test and other puposes (not for
production).
Thanks in advance..
-Regards
Vikram
Dan Foster
> I have a specific question regarding partitioning a Mid Range pSeries
> 650 Server.
> Below is the hardware specification:
> --------------------------------------
> Rack Server pSeries 650: 1 Qty
> 36.4 GB 10,000 RPM Ultra320 SCSI Disk Drive Assembly: 2 Qty
> 146.8 GB 10,000 RPM Ultra320 SCSI Disk Drive Assembly: 2 Qty
> 2-Way 1.2 GHz POWER4+ Processor Card: 4 Qty
> 4096MB (4*1024MB) SDRAM DIMM Memory: 4 Qty
>
> Wondering how many LPAR's I can do with the given configuration,
> reason I am asking is because one of our Sys. Admin's told us that we
> can only do 2 Partitions, because the pair of each disk drives are
> mirrored together.
You could ask him to not mirror the drives, but instead, allocate one drive
to each LPAR. I *think* the setup you describe would permit for 4 LPAR
partitions, maximum.
The p650 only has 4 internal hot-swappable SCSI drive bays... however, for
much more money, you can order a RIO drawer which supports up to 12 drive
bays per drawer with max of 8 RIO drawers (8x12 = 96 expansion disks max
plus 4 internal drives for total of 100 disks possible with the p650). This
is necessary only if your system administrator feels that mirroring is an
hard and non-negotiable requirement.
It would ordinarily not be a good idea to have unmirrored boot drives, but
it is easily possible. I would suggest having each partition backed up if
they are unmirrored to prevent loss of work if a drive ever fails.
-Dan
Steve Greatbanks
"Vikram Sharma" <sharm...@hotmail.com> wrote in message
news:43bf69f7.04022...@posting.google.com...
Bear in mind that unless you have the split backplane option, you will have
all 4 disks attached
to the same SCSI controller, and that can only be in the one LPAR. In that
case, you can only
have the machine as a single LPAR (unless you have some other disks you can
boot off).
We need more information about what the disks are attached to before we can
say more.
Darrell Hoffman
You will only be able to have 1 LPAR. The SCSI initiator (bus)
internal to the p650 can only be assigned to a single LPAR, and all of
the internal disk drives are accessed through the same SCSI initiator.
You would need to add PCI SCSI cards and external storage to have more
than 1 LPAR.
Bill
One thing I did in the past is create a single SCSI LPAR with a
mirrored SAN drive. This worked well, and since the SAN is now a
bootable media, it posed no concerns.
BV
Kurt Telep
Your Sysadmin is correct, with the given configuration, it looks to me
like you can only have 1 or 2 partitions, based on whether or not the
split-backplane feature code has been ordered from IBM
I'm assuming from your post that you have all 4 disks loaded into the
internal SCSI drive bays. If you look in the p650 Technical guide,
there are two configuration option for the internal drive bays, a
single and split back-plane. With the split backplane, a second SCSI
adapter is added and the internal drive bays are split across both
adapters, allowing you to have two individual partitions, each with
two disks. Remember, in an LPAR environment you can only assign an
entire adapter to a given partition, not individual disks.
If you need to run a 4 LPAR environment, you again have a few options.
Dan above mentions a D20 I/O drawer. This has 2 6-disk drive bays on
the front that can be separated and have 6 or 8 I/O slots on the back
(I'd have to walk into the machine room to check)
If you don't need the adapter slots, you can simply add SCSI adapters
in a D10 drawer and then attach any number of 2104 Disk arrays which
total up to a cheaper package.
I cannot stress how important it is to mirror your rootvg devices if
you cannot afford downtime. Even restore from local tape can take
hours dependent on the size of your system image. With mirrored
disks, there's just an item in the error report and an email from the
Service Agent.