Hi all , 
We manage a server  DR setup which uses a old version of MIMIX for replication.
We were planning on upgrading to latest version of MIMIX.

Our storage is based on SAN -  Flash System . I see that we have license for remote copy too. 

Is it a better idea to have a 3 point DR setup using remote copy over IP rather than upgrading MIMIX

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Geomon Joshy
IBM i Admin
Tata Consultancy Services
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Hi Joshy, 

Both two different beasts:

• mimix is logical replication, compare it with log shipping on MS SQL
• remote copy (or policy based replication) on flash systems is block based replication and unaware of the meaning of these blocks

When you are tired of verifying compare reports and correcting failures, you could move to storage replication. When the Flash system states data is in sync, it IS completely in sync. 

When you want to use your DR-server to query the data, you can't use full system storage replication, because the target server must be down. 

Full system storage replication does not protect you against OS failures. Because the DR server, in case of Mimix, is running a different copy of the OS, you ARE protected against OS failures. 

In my oppinion, it is better to compare Mimix with PowerHA managed storage replication. IBMi PowerHA allows you to use storage replication for an iASP and thus have the production system and DR-system online and ready to take over while your application and its data resides in an iASP which is rebustly replicated using the proven technology of remote mirror or policy based replication. 

So there are PRO and CONS for both options. The answer to your question depends on your preferences and requirements. 

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David Vanmanshoven
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Hi , 

My end goal here is to understand if the remote copy license we have can be put to use and further more if that helps to reduce our operational costs.
For the OS Failure , We Have A Development LPAR on the DR server ( which don't need to be replicated ) . if we can manage to move files to iASP . Wouldn't i be able to Vary off the IASP in DR Lpar and Vary it on the Development Lpar wouldn't that protect against OS failures.
For the replication should the entire DR Server be down or just the LPAR? 

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Geomon Joshy
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Original Message:
Sent: Thu April 30, 2026 05:47 AM
From: David Vanmanshoven
Subject: MIMIX V/S remote Copy ( Flash System )

Hi Joshy, 

Both two different beasts:

• mimix is logical replication, compare it with log shipping on MS SQL
• remote copy (or policy based replication) on flash systems is block based replication and unaware of the meaning of these blocks

When you are tired of verifying compare reports and correcting failures, you could move to storage replication. When the Flash system states data is in sync, it IS completely in sync. 

When you want to use your DR-server to query the data, you can't use full system storage replication, because the target server must be down. 

Full system storage replication does not protect you against OS failures. Because the DR server, in case of Mimix, is running a different copy of the OS, you ARE protected against OS failures. 

In my oppinion, it is better to compare Mimix with PowerHA managed storage replication. IBMi PowerHA allows you to use storage replication for an iASP and thus have the production system and DR-system online and ready to take over while your application and its data resides in an iASP which is rebustly replicated using the proven technology of remote mirror or policy based replication. 

So there are PRO and CONS for both options. The answer to your question depends on your preferences and requirements. 

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David Vanmanshoven
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Dear Geomon

Is there any pain point(s) with using MIMIX that you want to address?

Is minimum time desired in DR switchover event?  Mimix or any logical replication products accommodate fast DR switchover time for IBM i server. Disk replication can do similar thing only when you use a combination of IBM i System ASP and Independent ASP and do disk replication on IASP.    If you do not yet have this separation of ASP in place now in your IBM i server, it takes time and effort and also investment to make changes for disk replication DR implementation.

Are you currently doing some read-only workloads (report generation and such) and/or data backup in DR server?  Are you currently exercise a policy of switching over between the production and DR servers on a regular basis such as every 3 or 6 months?  It takes time and effort and also investment to implement disk replication to achieve the same.  

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Satid S
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Hi  , 

We have necessary space to create IASPs on both production and DR system.
In the DR site we are currently running backup but we have plans/thinking to run a VTL backup on production system and replicate the backup (VIA VTL device) to a VTL in the DR site overriding the need to take a backup from the DR site.

We are currently doing some reporting work on the DR Lpar but can moved back to Production if we get rid of the CPU load that MIMIX takes

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Geomon Joshy
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Original Message:
Sent: Thu April 30, 2026 08:20 PM
From: Satid S
Subject: MIMIX V/S remote Copy ( Flash System )

Dear Geomon

Is there any pain point(s) with using MIMIX that you want to address?

Is minimum time desired in DR switchover event?  Mimix or any logical replication products accommodate fast DR switchover time for IBM i server. Disk replication can do similar thing only when you use a combination of IBM i System ASP and Independent ASP and do disk replication on IASP.    If you do not yet have this separation of ASP in place now in your IBM i server, it takes time and effort and also investment to make changes for disk replication DR implementation.

Are you currently doing some read-only workloads (report generation and such) and/or data backup in DR server?  Are you currently exercise a policy of switching over between the production and DR servers on a regular basis such as every 3 or 6 months?  It takes time and effort and also investment to implement disk replication to achieve the same.  

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Satid S
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Hello,

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Guido Martinez
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Dear Guido

>>>> If you can't use an IASP, upgrading MIMIX remains your only viable option to maintain switch automation. <<<<

The customer can also consider replacing MIMIX with another logical replication solution that costs less.  Some 10 years ago or so in my geography, MIMIX in many IBM i customers was replaced by another competitive product the price + maintenance cost of which, spread over 3-5 years, was much less than MIMIX's maintenance over the same spread of time.  This makes me wonder if MIMIX has now adjusted its cost to be more competitive or not.  

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Satid S
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Original Message:
Sent: Mon May 04, 2026 03:21 PM
From: Guido Martinez
Subject: MIMIX V/S remote Copy ( Flash System )

Hello,

Yes, it's a superior technological evolution, especially if you already have Remote Copy licenses on your FlashSystem.

 

My Recommendation:

Migrate to Remote Copy/PowerHA for the bulk of your data (database). It's much more stable and eliminates lag due to CPU load.

Use Metro Mirror (synchronous) for the local site and Global Mirror over IP for the DR site or PBR.

Keep in mind the IASP: To use PowerHA, ideally you should move your applications to an IASP (Independent ASP). If you can't use an IASP, upgrading MIMIX remains your only viable option to maintain switch automation.

 

In short: If you're looking to reduce administrative burden and increase data fidelity, Remote Copy is the way to go. If you need the DR server to be "alive" for reporting or backups while replicating, stick with MIMIX.

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Guido Martinez
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Dear Satid,

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Guido Martinez
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Original Message:
Sent: Tue May 05, 2026 03:33 AM
From: Satid S
Subject: MIMIX V/S remote Copy ( Flash System )

Dear Guido

>>>> If you can't use an IASP, upgrading MIMIX remains your only viable option to maintain switch automation. <<<<

The customer can also consider replacing MIMIX with another logical replication solution that costs less.  Some 10 years ago or so in my geography, MIMIX in many IBM i customers was replaced by another competitive product the price + maintenance cost of which, spread over 3-5 years, was much less than MIMIX's maintenance over the same spread of time.  This makes me wonder if MIMIX has now adjusted its cost to be more competitive or not.  

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Satid S
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Original Message:
Sent: Mon May 04, 2026 03:21 PM
From: Guido Martinez
Subject: MIMIX V/S remote Copy ( Flash System )

Hello,

Yes, it's a superior technological evolution, especially if you already have Remote Copy licenses on your FlashSystem.

 

My Recommendation:

Migrate to Remote Copy/PowerHA for the bulk of your data (database). It's much more stable and eliminates lag due to CPU load.

Use Metro Mirror (synchronous) for the local site and Global Mirror over IP for the DR site or PBR.

Keep in mind the IASP: To use PowerHA, ideally you should move your applications to an IASP (Independent ASP). If you can't use an IASP, upgrading MIMIX remains your only viable option to maintain switch automation.

 

In short: If you're looking to reduce administrative burden and increase data fidelity, Remote Copy is the way to go. If you need the DR server to be "alive" for reporting or backups while replicating, stick with MIMIX.

------------------------------
Guido Martinez

Original Message:
Sent: 5/4/2026 3:21:00 PM
From: Guido Martinez
Subject: RE: MIMIX V/S remote Copy ( Flash System )

Hello,

Yes, it's a superior technological evolution, especially if you already have Remote Copy licenses on your FlashSystem.

 

My Recommendation:

Migrate to Remote Copy/PowerHA for the bulk of your data (database). It's much more stable and eliminates lag due to CPU load.

Use Metro Mirror (synchronous) for the local site and Global Mirror over IP for the DR site or PBR.

Keep in mind the IASP: To use PowerHA, ideally you should move your applications to an IASP (Independent ASP). If you can't use an IASP, upgrading MIMIX remains your only viable option to maintain switch automation.

 

In short: If you're looking to reduce administrative burden and increase data fidelity, Remote Copy is the way to go. If you need the DR server to be "alive" for reporting or backups while replicating, stick with MIMIX.

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Guido Martinez
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As of now we are using the DR server for reporting and backup. But with proper planning we can move this entirely to the production system. Freeing up tasks to switch of the DR LPAR

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Geomon Joshy
------------------------------

Original Message:
Sent: Mon May 04, 2026 03:21 PM
From: Guido Martinez
Subject: MIMIX V/S remote Copy ( Flash System )

Hello,

Yes, it's a superior technological evolution, especially if you already have Remote Copy licenses on your FlashSystem.

 

My Recommendation:

Migrate to Remote Copy/PowerHA for the bulk of your data (database). It's much more stable and eliminates lag due to CPU load.

Use Metro Mirror (synchronous) for the local site and Global Mirror over IP for the DR site or PBR.

Keep in mind the IASP: To use PowerHA, ideally you should move your applications to an IASP (Independent ASP). If you can't use an IASP, upgrading MIMIX remains your only viable option to maintain switch automation.

 

In short: If you're looking to reduce administrative burden and increase data fidelity, Remote Copy is the way to go. If you need the DR server to be "alive" for reporting or backups while replicating, stick with MIMIX.

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Guido Martinez
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Several people in this thread have said if you don't have IASP, you limited to using Mimix or another logical replication solution.  That is absolutely NOT true. 

You can use the IBM Full System Replication toolkit https://ibm.biz/FSRManager  to leverage storage remote copy for a DR solution without the need for migration to IASP.  You can further leverage the Full System Flash Copy toolkit to eliminate backup downtimes and still have confidence that all of your data is actually backed up.

The DR target would be offline unless you were doing a role swap or detached test, so it would add the time to IPL to the recovery time objective (RTO), but it is considerably easier to monitor and manage than logical replication and does not have the risk of missing data or inconsistent recovery points..

The logical replication vendors will tell you that you may be facing a long RTO because of potentially long IPL times, but I would suggest that you talk to actual customers about their test role swap and recovery timings and decide for yourself.  Ask every one of them when the last time they did a full role swap how long it took.  Was all of the data replicated consistently?  Do they do role swaps?  Why not?   Do this with customers for all the solutions you are considering and pick the ones that meet your needs.    I think you are probably already well aware of the disadvantages of logical replication or you would not be asking the question.

Logical replication has its place.  For example, if you want to use a near real-time read replica for reporting,  or you only want to replica a single application in a non-IASP environment.

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Vincent Greene
IT Consultant
Technology Expert labs
IBM
Vincent.Greene@ibm.com


The postings on this site are my own and don't necessarily represent IBM's positions, strategies or opinions.
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Hello Geoman, 

Assure MIMIX supports all IBM i topologies for resiliency without exposure to the single level store related challenges that hit you at the worst possible time (damaged objects, rebuilding of access paths, abnormal vary on, IPL, unpredictable RTO).

MIMIX supports 2-node or 3 node or more, with and without IASP.  The conversion to IASP is a project. 

Snapshot/Flash Copies are better with Assure MIMIX because the quiesce can be done without impact to the production application.

For a reporting system, be sure to consider the Ignore Attributes Feature which allows for target side objects to be modified (add or remove LF/Views, triggers, Foreign Keys (*REFCST)).  By doing this the Data comparison audits will not report the difference.  You would only do this on a non-switchable node.  If it is switchable, then you would want everything identical.

Lots and lots more can be done.

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Dan Simms
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