Change cache memory size on HA target

[jhamm@logos-data.com]

Is there a way to change the cache memory on an existing HA target? We recently upgraded the RAM on our two HA nodes, and want to assign more memory to the cache on each of our targets.

Thanks,
Jeff

[Anatoly (staff)]

Hi!
Unfortunately we haven`t got functionality that`d allow to do this on-fly, so basically you need to re-create it and specify the required ammount of RAM for cache in the target/device wizard.

[jeddyatcc]

I would just like to bump this as a feature request. Even if the process remained the same(dropping the target and recreating it), but was automated, it would be much better. I'm going to be experimenting with the powershell commands this year, but I'm not sure whether it will work with this.

[jhamm@logos-data.com]

I'm still learning the product, so bear with me

If I can "power off" all of the VMs residing on the HA target, can I recreate the HA target with upgraded cache using the old device and then just power the VMs back on with minimal downtime? Or is there a better way of doing this?

Thanks,
Jeff

[jeddyatcc]

Working from memory, so please try in test environment if possible. In my experience, no downtime is required as long as you only upgrade one target at a time. If you leave the img file alone, the it should go just fine.

1. On one node remove the replica from the HA device.
2. On same device add a new partner. I believe that when you add it back you can change the amount of cache.
3. After synchronization, confirm that your servers are connected and repeat for the other nodes.

[Anatoly (staff)]

I would just like to bump this as a feature request.

Its already in the list

If I can "power off" all of the VMs residing on the HA target, can I recreate the HA target with upgraded cache using the old device and then just power the VMs back on with minimal downtime? Or is there a better way of doing this?

Yes, you can, but to be more exact you need to use the image files, not devices. Importunately jeddyatc is not 100% correct: as far as I understood he said that you can just remove/re-add partners (replicas) and specify new cache size in wizard. It should be done by removing all entire HA (keep the image files), and re-creating it. Jeddyatc, please correct me if I misunderstood you.

[jeddyatcc]

That is what I thought, as when you look at the screenshots provided by Max, it looks to ask you for new cache settings. But, he may have been recreating a new HA device. So, just to be clear to change the cache size on an HA target, you need to take the target completely offline and recreate the HA targets using the same img files. Correct?

[Anatoly (staff)]

Yup, we are 100% on the same page on this
Just want to add that we`ll have technology that allows to change cache settings on fly in future releases.