RAID 0+1 to RAID 5

[Patrick Chim]

Hi,

I have VA7100 and VA7410. Each VA have 15x36GB disks and running RAID 0+1.

1. In a single VA, is it possible to have some LUNs be RAID 0+1 and some LUNs be RAID 5 or is it a global setting of a single VA ?
2. If I need to convert both VA to RAID 5, how many space will be free up in both VA ? Is it the same on both VA regardless of the model ? Is there a formula to calculate the size ?
3. For RAID 5, is it only occupy 1 to 2 disks for redundant purpose and all the other disks for storage purpose ?

Sorry having too many questions !! :)

Regards,
Patrick

[Uwe Zessin]

The VA uses RAID0+1 by default. You can switch your entire storage array into AUTORAID mode. If the used space grows over 50% (I think) the array begins to store data that is not accessed often into RAID5DP (DP = double parity). It reserves the right to migrate often used data from RAID5DP back to RAID0+1. The array decides on its own when it does this and which data it uses.

The VA is a 'VIRTUAL ARRAY'. All disks are either pooled in one (VA71xx) or two (VA74xx) redundancy groups. Your LUNs take space from these groups. You cannot dedicate disks to a RAIDset like on traditional RAID arrays.