RE: SAN Attached to iSeries - Anyone?

["Walden H. Leverich" <WaldenL@xxxxxxxxxxxxxxx>]

>But once you've defined a bunch of 'small' drives, won't OS/400 
>simply dump them into the (designated) ASP, and make them available 
>as part of the Single Level Store? 

Yup. Of course the annoying thing is that I have to define a UDFS to
allow IFS to use the storage if it's not in the system ASP. 

>IIRC, there was talk about the 'problem' of dealing with OS/400 and 
>SANs-- OS/400 takes all the space available to it and adds it to the 
>S.L.S., which is not the way PCs work-- PCs grab space as needed.

PCs do the same thing as the iSeries. If I define 10 LUNs (logical
drives on the SAN) at 100G each I've "used" up 1TB of that SAN. It
doesn't matter if I store 1TB of data on that space or 1 byte of data,
it's committed to the machine that mounts the LUNs. Of course, if I only
needed 100G I'd only mount one LUN and then come back later and mount a
second when I need it. But that's no different than adding drives to the
iSeries as needed.

Of course, the thing I don't get is RAID on the SAN. The SAN redbook
(http://publib-b.boulder.ibm.com/Redbooks.nsf/RedbookAbstracts/sg246220.
html?Open) seems to imply that I would start parity protection for the
"drives" so that OS/400 RAID-5s them. That makes no sense to me since
most larger SAN units take responsibility for RAID themselves at the
hardware level (under the LUNs)

-Walden 


------------
Walden H Leverich III
President & CEO
Tech Software
(516) 627-3800 x11
WaldenL@xxxxxxxxxxxxxxx
http://www.TechSoftInc.com 

Quiquid latine dictum sit altum viditur.
(Whatever is said in Latin seems profound.)
 
-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of PaulMmn
Sent: Thursday, March 18, 2004 8:27 AM
To: midrange-l@xxxxxxxxxxxx
Cc: Sue Baker
Subject: Re: SAN Attached to iSeries - Anyone?

But once you've defined a bunch of 'small' drives, won't OS/400 
simply dump them into the (designated) ASP, and make them available 
as part of the Single Level Store?

IIRC, there was talk about the 'problem' of dealing with OS/400 and 
SANs-- OS/400 takes all the space available to it and adds it to the 
S.L.S., which is not the way PCs work-- PCs grab space as needed.

--Paul E Musselman
PaulMmn@xxxxxxxxxxxxxxxxxxxx


>Walden H. Leverich wrote:
>
>>  Do we
>>  have to define the space as lots of small drives, or will the
>>  iSeries support a single 2TB drive?
>>
>
>Yes, you have to use multiple "small" drives.  Any external
>storage device must emulate the valid physical device sizes. 
>With V5R2, valid sizes are 8.5, 17.5, 35.12, 36, and 70 GB.
>
>--
>Sue
>iSeries Advanced Technical Support
>Rochester, MN
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