Increasing MSA20 capacity

[Marco DV]

Hi, I manage a MSA20 array connected to a Smart Array 6400 controller on an HP ProLiant DL380 G4 machine.

The MSA20 currently has 12 250GB drives, separated into 3 logical drives having around 700GB capacity each (each logical drive is made up of 4 physical disks and is configured as RAID5).

I would like to know how much can I increase the capacity of the array, while still keeping the same configuration (3 logical drives).

I've read elsewhere of the 2TB LUN size limit.

Does this mean that each logical drive cannot be bigger than 2TB? Or does this limit apply to the size of the RAID volume instead (which for RAID5 is 33% larger than available capacity)?

And does each logical drive need to match an exact number of physical disks?

For example, let's suppose I replace all 250GB disks with 1TB ones.

Each logical drive would be around 3TB. Would it work?

Otherwise, would it be possible to create logical drives of exactly 2TB, by distributing them unevenly over the physical disks, and then have remaining space for a 4th logical drive?

If all this is not possible, I suppose my only choice would be using 500GB drives to double the current capacity...

Thank you for any advice.

Marco

[Johan Guldmyr]

Hi, 

http://h18000.www1.hp.com/products/quickspecs/11587_div/11587_div.html#Technical Specifications

it's 6400 per Logical Drive, you can however create larger arrays.

You could create a larger array and then inside the array create multiple logical drives.

For example a large RAID6 (ADG) of 12x1TB (so 10+2) giving 10TB and then 5 x 2TB logical drives.

Another option like you mentioned would be to create three RAID5 giving 3TB useable space per array and create two logical drives in each array.