Formatting to 4096 bytes, does it matter?

[jcl333]

I am building an array with a combination of HGST HUSMM1640ASS201 eSSDs and Seagate Constellation ES.3 ST4000NM0023 4TB SAS drives.

- The SSDs are natively 4096 drives, and will let me format them either way
- The spinners are natively 512 (specs list 512, 520, 528) *BUT* it will let me format them 4096

- I am particularly wondering if this might be a bad thing?​

- I am assuming my LSI RAID controller would not appreciate mixing different sizes in the same array (SSDs used for caching)

I tried A/B with the SSDs and tested performance, no appreciable difference.
I know there could be penalties with small files and possible benefits with large one's, don't know how big the difference would be.
I don't think I have ever seen any storage device that likes being pelted with tiny files.

Anyway, is there a compelling reason here to go one way or the other that people can think of?

Thanks

-JCL

 

[i386]

Formatting to 4096 bytes, does it matter?

"It depends", 4KByte sectors are more efficient, see Advanced Format - Wikipedia

- The spinners are natively 512 (specs list 512, 520, 528) *BUT* it will let me format them 4096

I would not try to format hdds that use 512Bytes NATIVELY, the firmware probably won't recognize the drive after the format.

- I am assuming my LSI RAID controller would not appreciate mixing different sizes in the same array (SSDs used for caching)

I don't know if broadcom raid controller support ssds with sector sizes over 512 Bytes, but adaptec/microchip controllers don't support them for caching/maxcache.

I know there could be penalties with small files and possible benefits with large one's, don't know how big the difference would be.

May I ask what filesystem you use that doesn't have 4KByte as the standard size for chunks/blocks?

 

[jcl333]

"It depends", 4KByte sectors are more efficient, see Advanced Format - Wikipedia

Yup, makes sense, I am thinking maybe it is safer to stick with 512 especially on these older disks.

I would not try to format hdds that use 512Bytes NATIVELY, the firmware probably won't recognize the drive after the format.

Interesting, I am surprised it even let me do it, I expected it to fail. We'll find out, the format is almost finished.

I don't know if broadcom raid controller support ssds with sector sizes over 512 Bytes, but adaptec/microchip controllers don't support them for caching/maxcache.

I will go through the manual again and see if there is any mention of it.
Broadcom Inc. | Connecting Everything
Looks like my controller supports it, but it mentions CacheCade does not, so similar to Adaptec in that case at least.

May I ask what filesystem you use that doesn't have 4KByte as the standard size for chunks/blocks?

Sure, I will be using either NTFS or ReFS.

I think this answers my question ;-) Don't do it, potential for problems and not a clear tangible advantage.
Good to know.

-JCL

 

[vanfawx]

Another difference is you can't BIOS/legacy boot a 4k native disk. EFI only. That's probably less of an issue now

 

[Evan]

Also old versions of vSAN don’t like 4K disks (not that it’s being used here)