Rob,
You hit the nail on the head.
HA/DR solutions cannot handle OS upgrades and/or Application upgrades (application files with field changes)
They need to be shut down in these situations.
All they vendors have admitted that.
Those are two times I would want an HA/DR solution.
Planned/unplanned outages, with no changes, they will do their job.
Paul
-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Rob Berendt
Sent: Thursday, March 29, 2018 3:59 PM
To: Midrange Systems Technical Discussion
Subject: RE: What is the difference between Flash storage and a Flash Storage system like the V9000/V7000
In my experience the role swap time is minimal. I've done it in just a couple of minutes.
What really takes a while is quiescing the system to get ready for it.
Now, some on this list take a more thermonuclear approach in quiescing their systems. Apparently it works for them.
I've used Mimix. I've since migrated to Quick-EDD.
The major problem I had with Mimix was how long it took them to get new features added, like RCAC, temporal tables, etc.
Enough people told them goodbye that I think they've seen the error of their ways.
I had a tough time trying to get my head around how you do upgrades with the whole SAN and PowerHA stuff.
Someone explained it on this list but since that doesn't seem to be in our foreseeable future I've let it slide.
Rob Berendt
--
IBM Certified System Administrator - IBM i 6.1 Group Dekko Dept 1600 Mail to: 2505 Dekko Drive
Garrett, IN 46738
Ship to: Dock 108
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http://www.dekko.com
From: "Steinmetz, Paul" <PSteinmetz@xxxxxxxxxx>
To: "'Midrange Systems Technical Discussion'"
<midrange-l@xxxxxxxxxxxx>
Date: 03/29/2018 03:37 PM
Subject: RE: What is the difference between Flash storage and a
Flash Storage system like the V9000/V7000
Sent by: "MIDRANGE-L" <midrange-l-bounces@xxxxxxxxxxxx>
Paul,
I'm a bit shocked at your IPL times.
My current P7-8205-E6C takes 2 minutes to shutdown, 5 minutes to IPL.
I'm also shocked at your role swap time, 2 hours.
I've had several demos/webexs with various HA vendors, they are all
claiming less than 5 minutes role swap time.
I'm still researching the various HA/DR solutions for possible future P9
config, if corporate commits.
The P9 is a definite.
HA/DR, we'll see.
We have a 2nd data center, connected via fiber.
Paul
-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of
Musselman, Paul
Sent: Thursday, March 29, 2018 3:13 PM
To: Midrange Systems Technical Discussion
Subject: RE: What is the difference between Flash storage and a Flash
Storage system like the V9000/V7000
The question becomes: How long can the company function without the
computer? 1 day? 6 hours? 2 hours (for an IPL of the other box)? 2
minutes?
Then you attach a price tag to each answer, and see when they say 'ouch!'
It's an insurance policy.
We have a DR system using dueling iSeries/V9000 configurations. The
V9000s keep each other in sync (using Consistency Groups because "Metro
Sync" ends up as 'synchronous' instead of 'async' when the buffers fill
up). No iASPs. So the copy is a system that needs an IPL to be usable.
That's about 2 hours (including futzing around, wringing hands), but
that's acceptable to the company.
We can make a flash copy of the DR copy and IPL that for auditing
purposes-- showing that the live system lives on the DR box and is usable.
iASP is nice, but where does the iASP live? If it's in the data center
and the data center goes out, or the iASP dies, there goes your HA
solution. You still need an off-site copy, either on tape or in a 2nd
box.
Paul E Musselman
PaulMmn@xxxxxxxxxxxxx
-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Jim
Oberholtzer
Sent: Thursday, March 29, 2018 2:46 PM
To: 'Midrange Systems Technical Discussion' <midrange-l@xxxxxxxxxxxx>
Subject: RE: What is the difference between Flash storage and a Flash
Storage system like the V9000/V7000
We are discussing the difference between and HA system and DR system, the
difference being simple. The HA box uses iASP and can do a switch in
minutes. The DR solution replicates the entire partition (the target
partition is powered off) and in the event of an unplanned switch has to
IPL
and recover from an unplanned outage.
A planned switch would be to initiate the switch (use the IBM Rochester
services toolkit to make it one command) and the local system powers off,
then starts the remote box, and reverses the flow of data. No rebuild.
ALL systems should be fully journaled and that minimizes the Database
Consistency since the system simply uses the journals to get everything
up.
Done properly an unplanned outage can be recovered from with relative ease
and minimal downtime.
Since the SAN is doing the replication that moves that workload off of the
Power Systems box saving quite a bit there.
--
Jim Oberholtzer
Agile Technology Architects
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