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15020
RAID 6
Hi all
We wanted to have 100 TB storage of RAID 6- out of which 70 TB with 3TB sata disks and 30 TB with 600GB SAS disks.
Please clarify how many disks of 3 TB and how many disks of 30 TB is required for usable 100 TB with best performance of RAID 6.
Also please clarify part no: 403-BBDC related to MD3620f dual controller with 4 GB cache each.
Please clarify me ..its urgent
thanks
DELL-Kenny K
685 Posts
1
September 17th, 2013 10:00
After doing the math a number of different times. The configuration you want to do as having 70TB of free space using 3TB drives in a RAID 6, is just not possible as there are only 24 drive bays. With 3TB drives you will get about 2.6TB of free space as you have to count for the header space that will not be accessible and in a RAID 6 configuration you have to include 2 HDD's that are for parity. The most space you can get with 3TB drives will be close to 66TB without counting for the header space from each drive.
revmon
3 Posts
0
September 18th, 2013 03:00
Thanks for your reply. I forgot to mention that enclosures are added. Please help me with the number of disks required taking in to assumptions that free drives are available.
thank you
DELL-Kenny K
685 Posts
0
September 18th, 2013 09:00
Well you would need 26 Drives to get the 70TB in a RAID 6 configuration running 3TB HDD's. Then another 13 drives to get the 30TB array. The amount will not be exactly 70 and 30TB due to the header information that removes a little space from each drive. So in total you will need 39 HDDs that are 3TB in size to achieve the setup you are looking for.
revmon
3 Posts
0
September 19th, 2013 02:00
Is it the right way of grouping all 26 disks for RAID 6. Does it not affect the performance. Please suggest the best way of grouping for RAID 6. Is it 8 Disks + 2 Parity is the best way ?
Please clarify
DELL-Kenny K
685 Posts
0
September 19th, 2013 13:00
If you are needing to get a VD that size then creating one large RAID 6 is going to be the only option. You will not notice any kind of performance difference. It just depends what size you want the VD. You want to create a Raid array for each VD that you are wanting to create.