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Adding disks to existing array, steps?
https://3parug.com/viewtopic.php?f=18&t=469		 Page 1 of 2
Author:  Subversive [ Thu Nov 07, 2013 12:58 pm ]
Post subject:  Adding disks to existing array, steps?
Hi, we have a 3Par 7200 with the following current setup.

Shelf 1 - 18 x 450GB FC
Shelf 2 - 18 x 450GB FC
Shelf 3 - 8 x 100GB SSD

We recently ordered and received the following

12 x 450GB FC
12 x 3TB SATA.

When we ordered it, I assumed the 'installation and startup service' in the quote was for the HP on site team to come and install the disks, but having spoken to them, they advise me that is a software installation service. So, we are stuck doing it ourselves, as I don't have time to go back to my reseller and add this, wait for fulfillment, etc.

So, the plan was always to do the following:

Add 6 x 450GB FC to Shelf 1
Add 6 x 450GB FC to Shelf 2
Add 12 x 3TB SATA to Shelf 3.

Can anyone advise as to the process I need to follow to do this while the array is running? Thanks.
Author:  hdtvguy [ Thu Nov 07, 2013 1:07 pm ]
Post subject:  Re: Adding disks to existing array, steps?
What I find interesting is that when you ordered the original config they did not tell you that you would not be cage HA with anything over RAID 1. Someone should have configured that with 4 shelves and spread the drives across 4 shelves to at least give you cage HA in a RAID 5 3+1 config. Grated shelves rarely fail, but....

I don't thin I would add the 3TB drives to the same shelf as the SSD, I am not sure how the shelf handles IO, but then I am used to my P10000 which has FC loops point to point.
Author:  Subversive [ Thu Nov 07, 2013 1:14 pm ]
Post subject:  Re: Adding disks to existing array, steps?
So how would you add the drives then? 6 x 3TB to each of the first two shelves and 12 x 450GB to shelf 3?

We're going to need to add something other than just SSD drives to shelf 3, as it's nearly empty currently and I don't foresee 24 SSD's in my near future.
Author:  Architect [ Thu Nov 07, 2013 5:47 pm ]
Post subject:  Re: Adding disks to existing array, steps?
adding hardware yourself will void your HP 3par support contract as far as i know...

setting that aside:
- the 3TB drives are large form factor. Aren't the SSD and 450GB disks small form factor?
Author:  Subversive [ Thu Nov 07, 2013 5:52 pm ]
Post subject:  Re: Adding disks to existing array, steps?
Ok, I am checking with my reseller on the warranty issue and why they would sell me disks without including the installation service.

The first two shelves are 2U shelves, the 3rd is a 4U shelf. As I understand it, the 4U shelf can take both small and large form factor disks, is this right?

However your point is a good one, this means the 3TB disks would definitely need to go in that 3rd shelf.
Author:  Josh26 [ Thu Nov 07, 2013 9:53 pm ]
Post subject:  Re: Adding disks to existing array, steps?
Quote:
As I understand it, the 4U shelf can take both small and large form factor disks, is this right?


I'm happy to be corrected but I couldn't imagine how this could be correct - on every platform I've worked with, a backplane supports SFF or LFF, but not either.

However, refer here:
http://h20195.www2.hp.com/v2/GetPDF.asp ... 240ENW.pdf

Where it states:
the HP 3PAR Storage System Installation and Startup Service provides deployment of your HP 3PAR Storage System,

I'm sure you spoke to someone misinformed (as I did when I bought my two units) because extra hardware is always sold with an onsite technician to perform the installation, and that's always been referred to as "installation and startup" service.

Edit: Although every experience I've had with onsite technicians has been disastrous, so maybe you're better off this way :P
Author:  ailean [ Fri Nov 08, 2013 6:17 am ]
Post subject:  Re: Adding disks to existing array, steps?
Regardless of paying for installation (I've often seen multiple line items for install so it maybe one was missing, still bad on the reseller) HP should still be able to advise on the best slots to put the disks in. Admittedly there's not that many options with two SFF trays and one LFF tray.
Putting them in shouldn't be an issue but taking them out again can be so I'd verify best plan before starting. ;)
Author:  hdtvguy [ Fri Nov 08, 2013 6:38 am ]
Post subject:  Re: Adding disks to existing array, steps?
The 7000 series is designed to be customer install so I don't see how adding drives would void a warranty. As for how to lay out the disk I guess since the SAS shelves are really a serial daisy chain it may not matter too much since there is no concept of point to point like there is in the P10000. As mentioned though a shelf can fail you would probably experience corrupt data. Optimal config is to have enough shelves such that a RAID set puts chunklets across shelves so if a shelf fails the data is still there and accessible. We do 4 shelves and use RAID 5 3+1 with Cage HA so that chunklets should be spread across the shelves. I am not an expert in SAS connectivity so I don;t know how the IO actually gets processed especially within a shelf.
Author:  Architect [ Fri Nov 08, 2013 4:57 pm ]
Post subject:  Re: Adding disks to existing array, steps?
kluken wrote:
The 7000 series is designed to be customer install so I don't see how adding drives would void a warranty. As for how to lay out the disk I guess since the SAS shelves are really a serial daisy chain it may not matter too much since there is no concept of point to point like there is in the P10000. As mentioned though a shelf can fail you would probably experience corrupt data. Optimal config is to have enough shelves such that a RAID set puts chunklets across shelves so if a shelf fails the data is still there and accessible. We do 4 shelves and use RAID 5 3+1 with Cage HA so that chunklets should be spread across the shelves. I am not an expert in SAS connectivity so I don;t know how the IO actually gets processed especially within a shelf.


it was designed for it, but never released for (as of yet).
With the installation service, HP 3PAR support will also determine optimal placement.

There are rules and best practices on what to place where. e.g. with the P10000 series (FC) mags should always occupy the two most outer slots. the 7000 has a few similar rules. Why tinker around with it, and maybe cause issues later because of wrong placement?
Personally I would drop the current reseller and get a better one that really thinks with you, and takes these things out of your hands, instead of just selling drives...
Author:  Josh26 [ Sun Nov 10, 2013 9:47 pm ]
Post subject:  Re: Adding disks to existing array, steps?
kluken wrote:
The 7000 series is designed to be customer install so I don't see how adding drives would void a warranty.


I have numerous written statements from HP support stating otherwise.
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