HP EVA Continuous Access Error

[Dips123]

Hi Gurus

I am facing a situation which I don't know much about. I have a P6300 and 6500 which are at two different sites. I have continuous access licenses enabled and I have configured the fibre so that the EVAs can see each other. I have created 8 replication groups and they have synced and are working fine. However when I want to create any more I get the error

"Operation failed

Not enough data storage available in the disk groups, or no compatible disk groups available for the requested raid type. If this error occurred during a data replication operation please check if the requested capacity/raid level can be supported in the disk groups on both source and destination."

The error doesn’t make any sense to me simply because, the destination EVA has not got any disks provisioned. I was always under the impression that once the replication starts the source disks and disk groups are created in the destination EVA. I haven’t created any disk groups in the destination EVA because of that. Any ideas why is it failing? The destination EVA has space, I was under the impression that as soon as the replication is started the destination EVA will have the disks from the source EVA recreated for presentation during a disaster. Why is it then failing?

As you may already understand, I have not got a lot of experience with this, and I would appreciate greatly if any direction or suggestions are provided.

Thanks in advance.

Regards,

[giladzzz]

Hi

If you created DR groups you will notice that there is a copy of each disk replicated from the source system in the destination system and also for each DR group there is a log file created in both systems it's size by default is 100GB in raid 1 and that to consumes space so before you create more replication groups you have to see how much space you have in the destination system. you can also choose where to create the destination disks (you must create the disk groups in the destination system) if you have more than one disk group and also you can change the raid level ( don't choose raid 0 ).

Regards

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[Dips123]

Hi Giladzz

Thank you so much for your response. This is the thing that confuses me about the error that I get. The destination EVA has only the a couple of LUNs other than the replication disks. Combining tier 1 and 2 I see that there is about 21TB of free and only about 17% allocated. I also didn't realise that I have to create disk groups. Because as you say as soon as I start the replication, the disks are created on the destination EVA, so why do I need to create the disk group? From the error it appears as if there are no disk space on the destination EVA but that is not the case. 

As you can understand that this is something I don't have much experience with so any help is very much appreciated.

Thanks again for your assistance. It is much appreciated.

Regards,

[giladzzz · Accepted solution]

Hi

First of all as I said you must create disk groups at the destination array. When you create replication you need to choose two things the disk group at the destination array where the replicated disks will be created and where the log files will be on the source and destination array. If you don't make a choice EVA defaults to the largest disk group (even if there is not enough space in that group). This OK if there is just one disk group but otherwise unacceptable because you have to take in to account different disk type FATA and fiber.

So you have to look at the disk group where the replication is created to see if you have free space and not at the total array capacity.

Regards

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[Dips123]

Hi Giladzzz

Thanks for your response. Yes you are absolutely spot on. The logs for the replication were causing the creation process to fail. Once I changed the default log size, it was all good. I can't thank you enough for pointing that out.

One thing I wanted to ask was, after the initial sync is complete, it shows me that the log is not in use and there is no way to know that the files that are written to the source disk are replicated in the production site. Please find below one test replication set that I've created. It shows that the logs are not in use. But if the replication has started shouldn't the logs be in use? Also if the source disks are thick provisioned, then do the destination disks automatically become thick provisioned or is there a way to create the destination disk as thin provisioned to save space? Lastly, if I have multiple disk groups at the source, for eg: OS, Database, VMs, and I replicate them, is there a way to create separate folders to categorize them at the destination EVA replication set?

Name

Role

Write Mode

Log State

Repl_DFDB_BU_50

Source

Synchronous

Not in use

Thanks a lot again. I can't thank you enough for the help and support that you have provided already.

Regards,