Increasing disk size on RAID drives

Question

T710 server. Support shows RAID controller is PERC 6/i but sales tells me it is really H700... Server Administrator also show it as PERC 6/i.

First, how do I know for certain which one it is? In original config, it is listed as 341-8712 and the card under it is T954J.

But to the problem and question:

All 8 drives were originally 300GB, but one by one they were changed to 900GB. Two virtual disks, the OS at RAID 1 on disks 1-2 and RAID 5 on disks 3-8. The goal is to increase the virtual drive space to take care of the new, larger drives.

I read that the H700 card would allow the virtual disk size to be increased WITHOUT destroying the data in the virtual disk. In fact, I found a blog posting describing how to do this on the RAID 1 for PERC 6/i. Does that actually work, by deleting the VD and re-creating without initializing?

What about for RAID 5?

The reason why I called Dell Sales is to find out if a new H700-series RAID would in fact support this for what I call extending a VD dynamically (not necessarily through Windows but the RAID BIOS). Does the H700 do this, and if so, can I just replace the 6/i with a h700?

I didn't think so, so how could that work?

Thanks in advance.

LMHeimendinger · Answer

Thanks, don't have physical access to the server until I travel 100+ miles to get there and deal with the new drives. I am assuming that it is a PERC 6/i in the meantime.

Per the h700 controller, if I swap out the PERC 6/i for a H700, will the H700 recognize the virtual disks already on the drives, or does that "knowledge" sit on the controller itself? Can the H700 be made to recognize, i.e., manage the drives? Another question about swapping controllers: if the virtual disks are not recognized by it, and the system won't boot, how will it ever be able to add drivers for the new controller?

I also am aware there are several different controllers in the H700 family. Do all of them support disk expansion, or should I focus on a specific one?

theflash1932 · Answer

I would believe OMSA over 'sales' ... they don't know what's in your system. You could always look at the card itself ... the H700 will have mini-SAS (8087) connectors, the PERC 6/i will have 'regular old' SAS (8484) connectors. Don't do this on a PERC 6 ... it is called a retag ... it is not designed to do that - it is a recovery tool, not an expansion tool. If you have an H700, make sure the firmware is at the latest (you should update system firmware first, then RAID drivers before the H700 firmware).

theflash1932 · Answer

Configuration is stored on both the controller and the drives. When they differ, the controller will mark the drives as foreign. So, when you put in the H700, it will recognize the VD on the disks and if there is no configuration on the controller, it will automatically import it; if not, it will mark them as foreign and you'll need to import it. You'll need to either preload drivers through DISM, Recovery Environment, or insert the card prior to moving the disks to it. You should focus on the model intended for your server.

theflash1932 · Answer

Don't enter your Service Tag when looking for drivers - it will limit it to what was configured at the factory, and don't let it scan your system ... just browse by model.

You'll eventually want to end up with the H700 in the integrated storage slot.

LMHeimendinger · Answer

Very helpful, thanks,

Can I have both PERC 6/i and H700 installed inT710? that would certainly make the OS boot problem easier. It doesn't seem like Dell's support lets you download drivers for products it doesn't see on a system to just add the drivers without installing the card...

This part of server config is still a bit new to me,

LMHeimendinger · Answer

Thanks as you are driving me forward as I play around and search for more info. It does appear that I can install the H700 along side the PERC 6/I, and if I am correct, once that happens, Windows 2012 R2 will load the appropriate driver(s). Or grab them before switching cables. Having both cards in also makes it easier to manage preserved cache on the PERC 6/I if it is being used.

It seems that, according to the manual in the link below that Online Capacity Expansion is exactly what I am looking for, and that I can migrate from RAID 5 to 6 online with the 6 drive virtual disk. Yippee.

It is short on instructions on how to do this. Any furthering of my education? Thank you again.

http://i.dell.com/sites/doccontent/shared-content/data-sheets/Documents/perc-technical-guidebook.pdf

theflash1932 · Answer

The H700 drivers should be built into 2012+.

When you shut down the system, it should flush the cache, committing it to disk before the shutdown. Preserved cache would only normally be used in the event of a power outage.

It is pretty simple ... in OMSA, go to Virtual Drives, and select Reconfigure from the dropdown menu of Available Tasks for the RAID 5 ... it will start a wizard where you will select the disks to add and the ending RAID level. It will take HOURS to complete, wherein the performance will be degraded and your data at risk, so make sure you have a backup and a UPS.

PowerEdge HDD/SCSI/RAID

Increasing disk size on RAID drives

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