topic Re: SAS - Logical drive max size in ProLiant Servers (ML,DL,SL)

SAS - Logical drive max size

Darren Gannon — Tue, 28 Nov 2006 12:32:00 GMT

I have a new dl360 G5 with 6 72GB SAS drives attached to a smart array P400i and when i try to configure my logical drives its telling me the max size for a logical drive is 329395GB. Why is the max size so small?

Re: SAS - Logical drive max size

Darren Gannon — Tue, 28 Nov 2006 12:33:30 GMT

Sorry, its actually MB not GB.

Re: SAS - Logical drive max size

Michael Richter — Wed, 29 Nov 2006 05:16:16 GMT

Hi Darren,

P400:
Support for up to 2TB in a single logical drive.

What kind of Array ar u using? May u can attach an ACU Screen?

Cheers
Mike

Re: SAS - Logical drive max size

Rajashekar Chintakunta — Wed, 29 Nov 2006 06:16:54 GMT

Hi Darren,

I feel you are creating Raid 5 on this 6 x 72GB hdds.

The Array Capacity: (Size of Smallest Drive) * (Number of Drives - 1).

So it will be 72 * (6-1) = 360GB. That will be the max size of the array, but there is alos a overhead of the file system i.e some 5%. Because of that it is giving you 329395MB as the size.

Please check the following link for more info:
http://wiki.emdstorage.com/RAID/RAID5

Regards,
Raj.

Re: SAS - Logical drive max size

Darren Gannon — Wed, 29 Nov 2006 09:45:33 GMT

I guess it was the raid overhead. I don't see any unused disc space once the array was configured. I think its kind of dumb how the wizard makes the raid overhead look like available disk space. Or maybe i'm just dumb. : )

Re: SAS - Logical drive max size

Gus Kwong — Wed, 29 Nov 2006 11:21:20 GMT

Sounds like SAS disks have greater overhead than U320... I am pretty sure the DL380g3 with 6x72GB disks had available space more than that...