topic Re: Best practices for Disk groups in HPE EVA Storage

Best practices for Disk groups

Kevin Everts_1 — Wed, 07 Feb 2007 11:35:49 GMT

I currently have an EVA3000 with 28 FC disks and 8 FATA disks. The 28 FC disks are setup as a single disk group and the 8 FATA disks are the same way. I'm looking at adding 6 more FC disks in the near future (and possible another 14 next year). Should I add the new disks to my existing FC disk group or should I create a new one?

Is it better to have a few larger disk groups or many smaller disk groups?

Thanks.

Re: Best practices for Disk groups

Marek Nelec — Wed, 07 Feb 2007 11:43:02 GMT

The more spindles you have in the group, the better performance you'll have, so I would definitely add this new drives to the existing group.

Re: Best practices for Disk groups

Pshedges — Wed, 07 Feb 2007 11:49:22 GMT

Generally the more spindles in a disk group the better the performance.

I would suggest having just the 1 disk group unless you have any applications that require sequentially written data you may be better having a seperate disk group for this.

See http://h71028.www7.hp.com/ERC/downloads/5982-9140EN.pdf?jumpid=reg_R1002_USEN, this should help.

Re: Best practices for Disk groups

Pshedges — Wed, 07 Feb 2007 11:49:23 GMT

Generally the more spindles in a disk group the better the performance.

I would suggest having just the 1 disk group for FC and 1 for FATA unless you have any applications that require sequentially written data you may be better having a seperate FC disk group for this.

See http://h71028.www7.hp.com/ERC/downloads/5982-9140EN.pdf?jumpid=reg_R1002_USEN, this should help.

Re: Best practices for Disk groups

Rob Leadbeater — Wed, 07 Feb 2007 12:18:32 GMT

Hi Kevin,

As per the previous respondents you should add the 6 disks to the existing group as it will give you better performance.

One other thing to note is that you wouldn't be able to create a new disk group anyway, as a disk group must have a minimum of 8 disks...

Cheers,

Rob

Re: Best practices for Disk groups

Luk Vandenbussche — Thu, 08 Feb 2007 02:25:23 GMT

check the attachment

Re: Best practices for Disk groups

Luk Vandenbussche — Thu, 08 Feb 2007 02:26:43 GMT

check the attachment
attachment 2

Re: Best practices for Disk groups

Amar_Joshi — Thu, 08 Feb 2007 12:20:22 GMT

Kevin,

As all said, bigger diskgroup has better performance but remember the followings:

1. Rebuilding of DG will take longer in case of HDD failure.
2. Mixing of different sized in same DG (not sure whether you have all of same size or not?), always has overheads.
3. You need to plan for add-on with HP engineer to get an exact picure of your RSS state and may need re-arrangement of RSS disk locations.
4. LAST BUT NOT THE LEAST, IT'S GOOD TO HAVE DOUBLE DISK PROTECTION IN SINGLE DG RATHER THAN TO HAVE SINGLE DISK PROTECTION IN 2 SEPARATE DGs.

Hope my 10 cents worth.