Creating a RAID5 array on a RAID 4si card & DS2300

[Brad Marks]

I am adding four additional drives to a ds2300. My existing eight drives are defined as a single RAID5 array.
Since I will now have a total of 12 drives, I will need to configure multiple spanned arrays due to the 'eight disks to an array' limitation on the RAID 4si card.
Is there any difference in creating two arrays of six drives each v.s. six arrays of two drives each. All the documentation and forum posts I read always state two disks per array in examples.
Is there any advantage to either approach?
I will award points to answers...
Thanks,
Brad

[Greybeard · Accepted solution]

ok, first thing, make a backup before changing your RAID structure ;~} now, 8 disk raid 5 will cost you the capacity of one disk for parity leaving the other 7 for data, adding four more disks and creating another RAID 5 will give you the capacity of 3 for data and use 1 for parity. this gives capacity of 10 disks from 12. (any combination of disks making two RAID 5s will result in this. making 6 x 2 disk arrays will then be 6 x RAID 1. RAID 1 uses 50% of the capacity for mirroring the data so you will have the capacity of 6 disks from the 12. A nett loss over your present setup. for extra space with some resiliance and minimal interruption I'd go for the extra 4 disk RAID 5.

[Brad Marks]

Thanks