Adding disks to existing disk group

[Gregg Dow]

Hi there;

We have a "mirrored" pair of production EVA8000's running BC & DR.

We have one disk group of (32)SATA 146GB's; one group of (8)1TB FATA's for mirrorcloning on one SAN, and finally another group of (16)SATA 300GBs. All set to Single drive protection.

We have just received 3 more SATA 300GBs for each SAN.

I was planning on just installing them one at a time vertically, then adding them to the exisiting 300GB group, all during business hours.

question: are there any concerns with this, or, do I need to do anything special with adding them into the existing disk group?

Thanks.

Gregg

[Víctor Cespón · Accepted solution]

First, the EVA uses fiber channel disks, not SATA, but anyway...

Just insert the disks on the EVA one by one, wait a few minutes between one and the next. Check in Command View that each disk is detected and there are no problems on the loops.

Then add the 3 disks at the same time to the existing disk group.

It will initiate a leveling to move data from the existing disks to the new ones.

[Gregg Dow]

ok, thanks, I guess I meant near-online for the 1 TB's.

So I don't have to worry about doing this during working hours, with the virtual disks being accessed by our users?

Thanks.

Gregg

[Johan Guldmyr]

Does anybody have the rss setup guidelines available?

For the 300GB "SATA" (FC I guess) DG.

Going from 16 to 19 disks in the disk group might cause an RSS split.

Now you have two optimal RSS 8+8.
But for 19 you will have 8+6+5? I guess..

Don't have the guidelines in my head but if it goes to 10+9 then no worries.

But if it starts to split - I have seen this cause some performance degradation during the split.

Also with 19 disks in a Disk Group you will not be able to use all space if you are using vraid1 disks. If you are using a lot of vraid1 disks it might benefit you more to add even amount of disks.

[Gregg Dow]

Hi;

Thanks for the response.

These are all set to VRAID5.

Gregg