Which is mirror and which is main?

[Akram_11]

Hello Guys,

I've a Proliant DL380 GEN10 server, and I've one array containing 2 logical drives:

• Logical drive 01 (RAID 1) contains 2 physical drives, so as per my understanding that drive 1 is main and drive 2 is its mirror, correct?
• Logical drive 02 (RAID 1+0) contains 6 physical drives, 3,4,5,6,7 and 8. So which one is main and which one is its mirro?  Like 3 is main and 4 is its mirror or 3,4 and 5 is main and 6,7 and 8 are their mirrors?

Thanks 

[Torsten.]

Sinces writes are done in parallel the drives are equal, no master and slave concept.

[Akram_11]

Hi Torsten,

I'm not an expert but what I understood from the attached picture is that the data will be stripped into 3 groups as my case as for physical drive 3 and 4 (Group-1) and drive 5 and 6 (Group-2) and drive 7 and 8 (Group-3). The data is stripped into those 3 groups and in each group the data is dupicated for each 2 physical drives. So whatever is on drive 3 is the same as 4. 

You can correct me if I understood worng. Thanks so much for your support

https://cdn.ttgtmedia.com/rms/editorial/storage_raid_10_mobile.png 

[Torsten.]

You are right and now I think I understand your question ...

You have mirrored pairs of disks and the stripes goes across these mirrored groups.

[Ihaqueit · Accepted solution]

Raid1- RAID array does not do any striping but uses the second drive purely for data mirroring.

(RAID 1+0) - Combination of RAID 1 and RAID 0, often called RAID 1+0. This is the most optimal solution as it combines data striping and data mirroring

 Diagrams A, B, C, D, E and F represents blocks,

• For example, if you have a total of 6 disks in RAID 10, there will be three groups–Group 1, Group 2, Group 3 as shown in the above diagram.
• Within the group, the data is mirrored. In the above example, Disk 1 and Disk 2 belongs to Group 1. The data on Disk 1 will be exactly same as the data on Disk 2. So, block A written on Disk 1 will be mirroed on Disk 2. Block B written on Disk 3 will be mirrored on Disk 4.
• Across the group, the data is striped. i.e Block A is written to Group 1, Block B is written to Group 2, Block C is written to Group 3.