topic Re: query about CTG ID on XP CA Replication in XP Storage

query about CTG ID on XP CA Replication

SEENIVASANP — Fri, 03 Jul 2020 08:16:34 GMT

We have following query about CTG ID on XP CA Replication, Currently our customer environment few arrays got CTG ID count of 100 as we see HPE CA guide says CTG ID will be support till 256. Since we discussed to increase the CTG to 256 or 128. However, vendor says if we increase the CTG ID will impact the array performance with respective of read & write. from my understanding CTG ID is just number used to manage the data consistency for device groups and this should not impact any array performance. Even to fully utilize the CTG ID (256) there should not be any configuration changes on the array. Whenever we add any config changes to the array it will store into the shared memory including CTG ID. We like to have your input which says any recommendation about CTG ID & what all needs to be considered while we reaching to CTG ID 256. While increasing CTG ID does array sees any performance issue? If yes what are those?

Thanks,

Srihari

Re: query about CTG ID on XP CA Replication

SudhakarRao — Fri, 03 Jul 2020 10:21:28 GMT

I dont think there is a straight forward answer to that. it always "depends".. depends on what the current performance levels. what the array workload. etc.. fact is, I havent seen a config that has 100+ CTGs.. i am not saying that there is none.. btut if we haven't heard of it..its probably working fine. in General. If htey have an issue now with the amount of CTGs they have.. then they will surely have more if they increase the number.

"Continuous Access Asynchronous, Continuous Access Synchronous, and Continuous

Access Journal volumes" --- this section in Raid manager user guide

you have details about CTG

Re: query about CTG ID on XP CA Replication

SEENIVASANP — Fri, 03 Jul 2020 11:15:42 GMT

none of the guide says about performance could be issue when increasing CTG ID 256. If that is the case HPE could be mentioned about when using more CTG ID's which are all needs to considered?

Here i do not see any relevant information.

Re: query about CTG ID on XP CA Replication

SudhakarRao — Mon, 06 Jul 2020 05:53:37 GMT

the small number of CTG's is better than higher number. It is nice to test the array max numbers, but in the real life the low numbers are always better. I do not see any reason to have 100 CTG's. I bleive thy can do it with 10 and it will give them better performance. Of course they need to use ThP and not basic provisioning...and so on. --it is from ERT.

Re: query about CTG ID on XP CA Replication

SEENIVASANP — Mon, 06 Jul 2020 06:02:31 GMT

Here is the reason to have more than 100 CTG ID in real time. Actually our customer has more than 300 application & db hence the customer wanted to have replicate at least 200 app & DB. For each DB & Application we have 200 horcm config filer & CTG ID. So, which is not possible to have only 10 CTG ID for 200 applications & DB.

hope this can help to understand the real time.

Re: query about CTG ID on XP CA Replication

SudhakarRao — Mon, 06 Jul 2020 06:33:54 GMT

it will affect performance but what parameters not clear. if you are facing peformance issue currently it will increase performance issue. so when you face peformance issue please raise a support ticket