Performance Impact on creating Virtual Disk Groups with different RAID Types

[MP14]

Hi All,

In our MSA 2040 Storage, we have currently 14 Disks which goes as:-

Virtual Disk Group 1=10 SAS Disks(RAID 6)

Read Cache= 2 SSD Disks

Global Spare=2 SAS Disks

Now, we are planning to add another 3 disks, so I'm bounded to create another disk group with RAID 5.

 Questions:-

1.Performance impact on storage with multi-RAID configuration.

2.How the data striping will happen in this case, can both the disks groups be used or will it be restricted to individual disks groups only.

[SUBHAJIT KHANBARMAN_1]

I would suggest to refer best practice technical paper and consider section "Disk Group Considerations",

https://h20195.www2.hpe.com/V2/getpdf.aspx/4AA4-6892ENW.pdf (Page no 22)

"With the GL200 and greater firmware on the MSA, allocated pages are evenly distributed between disk groups in a tier; therefore, create all disk groups in a tier with the same RAID type and number of drives to ensure uniform performance in the tier.
Consider an example where the first Disk Group in the Standard Tier consists of five 15K Enterprise SAS drives in a RAID 5 configuration. To ensure consistent performance in the tier, any additional disk groups for the Standard Tier should also be a RAID 5 configuration. Adding a new disk group configured with four 10K Enterprise SAS drives in a RAID 6 configuration will produce inconsistent performance within the tier due to the different characteristics of the disk groups.

"

Hope this helps!
Regards
Subhajit

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