RAID 6 configuration and subsequent addition of disks

[Robertomcat]

Hi, good afternoon.

I'm going to create a new 4×4 TB RAID 6 on a P440 4GB controller, and after a while I have to add more 4 TB disks up to a total of eight disks.

When I create the RAID I get the screen to choose the band size/duplication size, but I don't know which one I should choose, as the data to be stored is quite small (between 2MB and 3MB the file size).

I would like the reading performance to be higher for a database, and also to minimize the latency.

Should I choose the default configuration, or should I choose a smaller size? As for the file system, I'm going to incorporate NTFS, and I don't know what format I should incorporate either.

Thank you.

[sudhirsingh · Accepted solution]

Hi,

A smaller block size is suggest for better performance for small files,  so anything between 8 KB to 256 KB block size would be good, or rather go with the default selection.

However,
Please consider matching filesystem block size with database block size for best I/O performance.

IOPS and block Size has inverse relation with each other, as block size increases it takes longer to read a block so latency will be higher/low IOPS and when block size is small it increase IOPS (I/O per second).

If you feel this was helpful please click the KUDOS! thumb below!

Regards,

Sudhir

[Robertomcat]

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@sudhirsingh wrote:

Hi,

A smaller block size is suggest for better performance for small files,  so anything between 8 KB to 256 KB block size would be good, or rather go with the default selection.

However,
Please consider matching filesystem block size with database block size for best I/O performance.

IOPS and block Size has inverse relation with each other, as block size increases it takes longer to read a block so latency will be higher/low IOPS and when block size is small it increase IOPS (I/O per second).

If you feel this was helpful please click the KUDOS! thumb below!

Regards,

Sudhir

---

Thank you for your response.

So I will leave the band size at 64k and the file system at 64k as well, so that in the future we will not have problems adding more terabytes, and also because it will be the most optimal performance as you say.

One thing I forgot to mention, is that the disks are a HGST Ultrastar than in the 512n format. Is there a problem with this information?

[sudhirsingh]

Hi,

These advance format should not affect drive performance, as these drives are configured under raid controller with specific block size.

Assuming all the drives are of same size/specificatioin.

Regards,

Sudhir