Are you sure that we have to wait? This sounds like STRASPBAL
TYPE(*HSM) to me:
Hierarchical Storage Management (HSM) balancing - The 'high'
use and 'low' use data on each unit in the ASP is
redistributed so that the 'high' use data resides on high
performance units and the 'low' use data resides on low
performance units. The ASP being balanced in this manner must
contain the correct mixture of slow and fast units to perform
this type of balance. This allows the 'low' use data on the
high performance units to be moved to low performance units.
Data that is 'high' use that resides on slow units will be
moved to the fast disk units. HSM balancing cannot be done
until the trace controlled by the Trace ASP Balance
(TRCASPBAL) command has collected usage statistics. The
TRCASPBAL command starts the trace function that will identify
the 'high' and 'low' use data on each unit. After the HSM
balance activity has run to completion, the trace information
will be cleared. HSM balancing is useful when the ASP
contains compressed disk units.
Regards,
Scott Ingvaldson
Senior IBM Support Specialist
Midwest Region Data Center
Fiserv.
-----Original Message-----
From: William.Epperson@xxxxxxxxxxxxxxxxxxxxxxxx
[mailto:William.Epperson@xxxxxxxxxxxxxxxxxxxxxxxx]
Sent: Monday, September 28, 2009 8:09 AM
To: Midrange Systems Technical Discussion
Subject: Re: can POWER6 IBM i or System i run on non-IBM disk drives?
One of the upcoming benefits of the i is a PTF that will help "balance"
the I/O on the system with disproportionate storage. I spoke with one
of their technical people and sometime this fall they're releasing a PTF
that will help utilize SSD's. So you could put a couple of those large
format drives in the system and tie it to a couple of mirrored SSD's (or
more) and outperform more "arms" because the system will now do dynamic
balancing that used to require you to run a STRASPBAL *USAGE. The
system will now do it for you in i6.1 and POWER6. So you could compress
some slower SAN storage and tie it to faster internal storage and a
couple of SSD's and the system would scream. Kind of dynamically doing
what any good admin would do for his *nix system with separate file
systems and volumes. Now you can just have one big ASP and do the same
automagically on the i.
Bill Epperson Jr.
Systems Communications Analyst
Memorial Health System
(719) 365-8831
rob@xxxxxxxxx
Sent by: midrange-l-bounces@xxxxxxxxxxxx
To
Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
cc
09/28/2009 06:49 AM
Subject
Re:
can POWER6 IBM i or System i run on non-IBM disk drives?
Please respond to
Midrange Systems Technical Discussion
<midrange-l@xxxxxxxxxxxx>
Larry,
All great points, but I have to ask some questions anyway...
What's the smallest drive you ever had to rebuild a raid set on in an i
or it's predecessors? How long did it take? If you take a 140gb,
divided by the size of this smaller drive, and multiply the time it took
to rebuild this smaller drive would you get the time it took to rebuild
the 140? Or have they drastically changed the speeds of the newer
drives to bring down the time? Do you think that if IBM came out with a
1TB drive raid time would be a direct multiple of the time of the 140?
70GB are off the market, aren't they? And we found new 140's for about
the same price for the 70's. We ended up buying the same number of
140's as we would if they were 70's. (And the system is only 35% full.)
I wonder if 1TB's were the same price as 140's if they would still buy
the same number. (I'm having a feeling of deja vu on this paragraph.
Didn't we discuss this in the last year or so?) I can see some people
gagging at the thought of buying new disk when they are only 5% full
though.
Rob Berendt
--
Group Dekko Services, LLC
Dept 01.073
Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com
From:
Larry Bolhuis <midrange@xxxxxxxxxxxx>
To:
Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Date:
09/27/2009 11:22 PM
Subject:
Re: can POWER6 IBM i or System i run on non-IBM disk drives?
Sent by:
midrange-l-bounces@xxxxxxxxxxxx
Gadzooks is this guy speaking from a point of ignorance....
As has already been mentioned they are not the same and won't work
anyway, sector size, firmware, etc etc.
*IF* you got them to work then you would still have to deal with the
following issues:
1) Their MTBF is a mere fraction of drives designed and built for use in
servers that pound drives 24x7.
2) Their sustained throughput isn't as good as drives designed for the
purpose.
3) Consider protection. It takes roughly 3 hours to build or rebuilt a
RAID set on 140GB drives. Extend that to 1TB drives and you get about 21
hours! So WHEN (not IF, WHEN) one of those monster 1TB drives fails you
get a minimum of 21 hours of time with no protection and that's AFTER
the replacement drive is installed.
4) Consider that there have been multiple firmware issues with these
huge drives where they get 'bricked' and your data is gone.
5) Nearly every system I work on these days has plenty of disk capacity,
it's ARM count that's hurting, 1TB drives surely won't help that in any
way at all.
Even if you could you do NOT want these drives in your i.
- Larry
elehti@xxxxxxxxxxxxxxxxxx wrote:
Our network admin (a LINUX/PHP/open source/anti-IBM type of guy) says,
"If you need additional disk drives for your POWER6 IBM I machine, you
don't need to buy expensive disk drives from IBM.
Just buy some cheap 1-terrabyte Western Digital drives from Egghead,
etc. Their drives will work just fine."
Uh, I think that other drives would not work in this machine.
Your thoughts?
I don't know why I let his outlandish comments get under my skin.
Now I will post a question to IBM tech support and have them
verify/contradict his claim.
Then maybe I will be able to sleep undisturbed.
--
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