Query: 3par Set size and parity

[AshruTech]

Hi Teams,

I configured RAID 6 with 4+2 , if I have 20 disks in 3par,

how many disk failures are supported? 

how many disks will use ads parity? ( 6 +2 , 6+2, like or )

How can I calculate set size and parity disk?

[Cali]

Hi,

3PAR works in Chunklets (1GB), not in Disks, that's a very big advantage of 3PAR Technology.
So 6+2 means it writes 6 Data and 2 Parity, each on this Chunklet down to 8 different Disks.
With 20 Disks it looks like this:
D+D+D+D+D+D+P+P+D+D+D+D+D+D+P+P+D+D+D+D
D+D+P+P+.....

You see, that the 3rd Group span from last to the first Disk, that's no problem until they are on different Disks.
But you don't have to worry about it, it's done automatically, great, isn't it?

In this way, you can also use 8+2, 10+2 which give you more usable space.
I, personally would use 10+2 with Raid 6.

And about Failures, you see, that we can lose 2 Disks in each of these Groups.

Cali

[support_s]

System recommended content:

1. CUSTOMER ADVISORY: HP 3PAR StoreServ Storage and HP 3PAR Storage - Management Console Software v4.3 default step size not set correctly when changing CPG RAID type

2. HPE Smart Storage Administrator - Rapid Parity Initialization

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