Re: Disk Size for Nest OS Release of IBM i

[Jim Oberholtzer <midrangel@xxxxxxxxxxxxxxxxx>]

Just for testing purposes I created a 60GB partition ( all virtual ) 
with 6 10GB drives to see if the LIC and IBM i ( V7 ) would load. It 
did, so I think the limits are for "spinny" disk rather that virtualized 
disks. That said, I think my 60GB partition would be nearly full if I 
loaded all of the LPPs and PTFd them. It's been intimated by some IBMrs 
that 70GB may become a hard floor. If that's true then we need to look 
into Larry's idea to load up the first drive with the OS, then have at 
least 6 more drives of the size you need. Then set the 70GB drive to 
write only. Use only the other six or more drives..... of course pending 
a supported configuration....

See archives for a more in depth discussion......

Jim Oberholtzer
Chief Technical Architect
Agile Technology Architects

On 1/23/14 10:07 AM, DrFranken wrote:
> It's not a physical disk thing for the SCSI world because no SCSI
> machine will run IBM i 7.2 so scratch that.
>
> *IF*  (and this is DrFranken's guess) they stuck with the physical disk
> thing then 70GB is the smallest physical disk you can attach to a SAS
> based machine, which is to say Power6 and up. No you cannot purchase new
> 70GB SAS disks any longer BUT if i 7.2 is to support a Power6 machine
> which might legitimately have 70GB disks in it, there you go.
>
> That said I seem to recall conversations at last year's annual COMMON
> conference that they picked 70G for a different reason.
>
> We at iInTheCloud and iDevCloud do not like this 70G minimum for our
> small personal partitions especially as that's more disk space than any
> of our personal partitions even use today in total!
>
>           - Larry "DrFranken" Bolhuis
>
> www.frankeni.com
> www.iDevCloud.com
> www.iInTheCloud.com
>
> On 1/22/2014 4:36 PM, Kirk Goins wrote:
>
> > >It has been mentioned here that V7R2 ( or whatever the new release will be
> > >called ) will require a 70GB Loadsource.
> > >
> > >The real question here is what size to we really need? I believe this 70GB
> > >drive spec is based in the older SCSI drives not the physical space
> > >required. Where I am going with is vSCSI disks presented to IBM i from VIOS
> > >or a Hosting IBM i partition or even the size of disks that a SAN will
> > >present to IBM i.
> > >
> > >Let's talk 70GB SCSI Drives. If I Mirror my LS with a pair of 70GB drives
> > >then the OS will see 70GB. If my 70GB LS is part of a 4 drive Raid set I
> > >will see only about 53GB. INa 3 drive set I don't know as I Haven't done a
> > >3 drive set but if everything is even that will make those drives around
> > >47GB.
> > >
> > >
> > >Here's why I ask.
> > >New Power7 with 8 139.5 drives. After Raid5 those drives are 122GB  In this
> > >exampleI want to have an IBM i Hosting partition and 2 IBM i Guests. IBM
> > >suggest to have a minimum  of 6 vSCSI drives in a partition for
> > >performance. Now in creating cSCSI drives in IBM i for an IBM i Guest you
> > >loose about 7% if I remember correctly. So  each drive on the host needs to
> > >be about 75GB to present 70GB to the guest. So I need 12 of these. ( 12 x
> > >75 ) = 900GB that will leave about 76GB in the HOST. or about 71% usable if
> > >you keep the HOST at 90% used. If I can use slightly smaller drives I would
> > >a little more breathing room or room for a set of OS Image catalogs etc.
> > >
> > >No in this example I don't want run any work other than hosting in the HOST
> > >partition.
> > >
> > >Thoughts, Comments etc?
> > >
> > >--
> > >Kirk
> > >
> --