HPE Smart Array Controller Stripe Size matrix

[juzzy]

Hi All, 

I have a customer who is looking at deploy SSD drives in an RAID 5 array attached for a P408i-a SA Controller.  We are wanting to know what the maximum stripe (strip) size configurable would be across different drive quantities.   Is there a matrix or calculator that provides that information.  

Looking at the SSA it would appear that for 3 dirves it would to be 64KiB but ideally we want 512KiB or even larger, workload is video security footage.  Does anyone have any information on how can we determine the strip size supported for different drive quantities in RAID 5/RAID 6? 

thanks

[Vinod_R]

Hello 

Strip Size/Full Stripe Size Strip size is the amount of data that is stored on
each physical drive in the array. The full stripe
size is the amount of data that the controller can
read or write simultaneously on all the drives in
the array. For RAID levels that support fault
tolerance through parity, the parity information is
calculated one full strip size at a time.
For hardware RAID, you can specify from 16KiB
up to 1024KiB, depending on the number of disks
and RAID level. The default value is all available
space.
For Smart Array S100i SW RAID, the minimum
size is 16KiB and the maximum size is up to
256KiB, depending on RAID level and device
type.

Stripe size selection

When an HPE Smart Array controller makes an array, the unit of data that it manipulates is defined as a “strip” (ranging insize from 64 KiB to 1 MiB).
These strips are distributed across the physical drives in the array. A "stripe" is one set ofstrips. HPE Smart Array controllers configure strips, not stripes.
You can calculate the stripe size from:•Strip size•Number of physical drives in the logical drive•RAID levelThe best performance and drive longevity is obtained by aligning and sizing the strip and thus stripe size to theapplication I/O request size and alignment.
The smaller (<= 64 KiB) the strip size, the longer the background parity scansand rebuilds take and the more impact to the host I/O during these operations.

https://support.hpe.com/hpesc/public/docDisplay?docLocale=en_US&docId=emr_na-a00019059en_us

HPE Smart Array SR Gen10 User GuidePart Number: 879006-005Published: May 2020Edition: 5AbstractThis document includes feature, installation, and configuration information about Hewlett Packard Enterprise Smart ArraySR Gen10 and is for the person who installs, administers, and troubleshoots servers and storage systems. Hewlett PackardEnterprise assumes you are qualified in the servicing of computer equipment and trained in recognizing hazards inproducts with hazardous energy levels.

https://support.hpe.com/hpesc/public/docDisplay?docId=c03909334

Thanks & Regards,

Vinod Rawat 

[juzzy]

Thanks @Vinod_R for the information.   

That's all clear however what I'm after is a calculation or support matrix of the 'strip' size configuration across different RAID sets and drive quantities.  

For example. 

3 x HDD,RAID5 : Supported strip sizes configurable = 16KiB, 32KiB, 64KiB, 128KiB, 256KiB...

4 x HDD, RAID10 : Supported strip sizes configuration = .......128KiB, 256Kib, 1MiB

Does that make sense?   Is that information available? 

thanks