POWERHA supports multiple targets so you could create a second partition on the either box. Mirror to that also and then do the same thing there that you do now on the HA box to do the backups. However this way you're not stopping replication to the HA server and thus that server stays in sync.

Do be aware that with POWERHA there is no true 'queuing of changes' like there would be with the journal based tools. With PowerHA it's a bitmap of sectors that need to be updated. This is an advantage in that if the same disk sector gets update 100,000 times during the time the iASPS are disconnected, then POWERHA needs only to send it one time so 'catch-up' is faster. The Journal based tools need to send every change, and likely before and after as well. However it's not an advantage should you lose the production when the servers are disconnected as you have no way to recover from it. With the journal based tools you MIGHT be OK if the journal entries are already across the wire just not yet applied. You are still just as hosed however if it's a comm failure and all those journal transactions are stuck on the now-dead production server. Just food for thought.

- Larry "DrFranken" Bolhuis


On 9/27/2013 4:53 PM, Graap, Kenneth wrote:
I currently have a Power7 production system and a Power6 HA system, running IBMi in single partitions.

The systems are configured for iASP mirroring using the Geographic Mirroring feature of PowerHA for i Enterprise Edition.

Currently I suspend the Geographic Mirroring for a few hours a night to perform a backup to tape on the Power6 HA system.

During this backup the Power7 production system remains available to production users, but mirroring is suspended to the HA system. Any changes to production data are queued up to be sent when mirroring is resumed. After the backup completes on the Power6 HA system, mirroring is resumed and mirror synchronization is achieved in about an hour or so.

I want to come up with a way to eliminate the “mirror synchronization time” and still have a point in time BU to tape of all our production data.

One idea I was thinking about was to come up with a way to perform a FLASH COPY of the remote mirror (the iASP attached to the Power6 HA system), without having to suspend mirroring from the Power7 production system.

My question to you is, is this even possible to do this using the PowerHA for i Enterprise Edition software on the IBMi? I imagine it would require sufficient disk and another active partition on the Power6 system… Any thoughts on this idea or any other ideas on how I could eliminate having to resynchronize the Geographic Mirror as part of my nightly BU process????

AKA … 肯尼思 or 케네스
Kenneth E. Graap
System Administrator
503.226.4211 x5537

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