topic Re: HPE 3PAR CPG creation with new PDs in HPE 3PAR StoreServ Storage

CPG 3PAR creation with new hard disks after installation

mainland — Sat, 20 Feb 2016 08:50:33 GMT

Hi I have a cabin 3PAR 7200 with these hard drives and CPGs
36 x 900GB 10K SSF
24 x 3TB 7.2K LFF

We set these CPGs:
CPG1 this filter "-ssz 6 -HA mag -t -p -devtype FC r5" to hold all the disks FC

CPG2 this filter "-ssz 6 -HA mag -t -p -devtype NL r6" to hold all the disks FC

We have set new disks:

72 x 450 GB 10K SSF
36 x 3TB 7.2K LFF

Now the new disks are only initialized, you did not run the "tunesys" command.

I have several questions:

What is the best practice to run the system tunesys and add new drives to CPG FC existing FC and the same with the existing CPG NL hard drives?

or
To Create new CPGs with new hard drives? For this we must change the filter existing CPG? Can you change the filter for an existing CPG hot affect the system?

Best regards

Re: CPG 3PAR creation with new hard disks after installation

Sheldon Smith — Sat, 20 Feb 2016 21:37:36 GMT

Your choice. Best practice depends on what you are trying to accomplish. With the new disks initialized, the 450G 10K's are now part of CPG1. Run tunesys one or more times and CPG1 will be distributed across all the 10K disks. You will have better performance until the 450G drives are filled, at which point all subsequent volume creation/expansion will be only on the original 900G drives.
Or, you could create a third CPG, then add either the "-tc_gt 675" or "-tc_lt 675" option to restrict the desired CPG to either the 450G or 900G drives.
And run tunesys again one or more times.

Note: While I work for Hewlett Packard Enterprise, all of my comments (whether noted or not), are my own and are not any official representation of the company.
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Re: CPG 3PAR creation with new hard disks after installation

mainland — Sat, 20 Feb 2016 21:51:39 GMT

Thanks Sheldon, then I can modify existing filter CPG? This operation can be performed smoothly? Please note that the CPG is where the data currently Best regards

Re: HPE 3PAR CPG creation with new PDs

Dennis Handly — Sun, 21 Feb 2016 00:24:59 GMT

>CPG1 this filter "-ssz 6 -HA mag -t -p -devtype FC r5" to hold all the disks FC
>CPG2 this filter "-ssz 6 -HA mag -t -p -devtype NL r6" to hold all the disks FC

These are not really filters but specs for LD creation. Note that your "-t" goes next to your r5/r6. And it's -ha mag.

>Create new CPGs with new hard drives? For this we must change the filter existing CPG?

This is just asking for problems. See how complex Sheldon's options are. Just have the new disks in the same CPGs.

And do a tunesys.

> I can modify existing filter CPG?

Nothing to modify, the new PDs will be automatically be used by the CPGs.

Re: HPE 3PAR CPG creation with new PDs

Sheldon Smith — Sun, 21 Feb 2016 20:04:36 GMT

Having added disks to your system, presumably you will do one or more tunesys commands to re-distribute the existing load. And performance will improve. Subsequent storage will be added evenly across all FC disks. Consume enough and the new 450G's will fill up. After that, further storage will just be on the space left on the 900G's. And performance on that storage will be the same as it is now.