RE: save while active v7r1 - *IBM and also SAV

PowerHA does not use journaling at all in its replication, rather it copies
address blocks as the address block changes. So if address 1024 (and its 4K
block) is changed, the PowerHA takes that memory location and pushes it to
the remote site and applies it. PowerHA does not care what's in that block
of data, it just knows it needs to move.

PowerHA does have some limitations the biggest one being it replicated
Independent Axillary Storage Pools (iASP) and does not replicate some data
out of *SYSBAS.

Larry and I have been busily installing PowerHA over the last several months
at multiple customers. Done properly it is very easy.

As to the COMMON session Larry and I proposed one for this year but it was
not selected. Maybe next time.

--
Jim Oberholtzer
Chief Technical Architect
Agile Technology Architects


-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Horn,
Jim
Sent: Wednesday, April 08, 2015 5:05 PM
To: midrange-l@xxxxxxxxxxxx
Subject: RE: save while active v7r1 - *IBM and also SAV

I haven't been responsible for this for a few years but - sounds like this
would make a good COMMON session.

In PowerHA do you need to be doing remote journaling?

Jim

----------------------------------------------------------------------

message: 1
date: Wed, 8 Apr 2015 14:39:14 -0500
from: "Jim Oberholtzer" <midrangel@xxxxxxxxxxxxxxxxx>
subject: RE: save while active v7r1 - *IBM and also SAV

Rob brings up a salient point. ALL of your applications should be
journaled, regardless of if you use them for commit control or not.
It aids in speedier recovery from an abnormal termination, it aids in
SWA, and if set up properly with system managed journals, does not
require significant administrative work to manage them. In a PowerHA
environment it's essential to ensure properly managed HA clusters.
(the same is true for the journal based replication packages)

Another way to get past most of the complexity is BRMS. BRMS manages
most of the issues with respect to SWA nicely. The small investment
in BRMS will pay for itself in administration time, and recoverability
in very short order.

Another reason to use journals is to mitigate the need for getting
checkpoints across multiple libraries at one time. Granted
referential integrity might not be perfect without a multiple library
checkpoint but using journaling by application rather than library
boundary goes a long way to making that technique acceptable.

Very few of my customers have environments were the near restricted
state (however short) to achieve a synchronization point is required,
rather by using BRMS and good use of journaling you can achieve 98% of
what you what without the shutdown pain.

--
Jim Oberholtzer
Chief Technical Architect
Agile Technology Architects


-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of
rob@xxxxxxxxx
Sent: Wednesday, April 08, 2015 2:23 PM
To: Midrange Systems Technical Discussion
Subject: Re: save while active v7r1 - *IBM and also SAV

Jim,

I think you are a somewhat regular attendee of COMMON. That might be
a good place to really bone up.

Some search terms are: ragged save while active.
I think that might be the title of a redbook by Larry Youngren

With little to no journalling you may catch some grief.

Stream files are very picky and snicker at save while active.

Until we did the Mimix thing and started backing up from that we were
doing a crappy save while active. No checkpoint processing. No

journalling.

Didn't care if order header was in sync with order line, etc
SAVACT(*SYSDFN). The goal being: You can back up, just don't disrupt
the users from getting into the data. I argued against it but had to
bide my time until Mimix. Only took a few years...


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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