> 
> Well, there are the following 2 commands:
> 
> Get physical block size: 
>  blockdev --getpbsz <device>
> Get logical block size:
>  blockdev --getbsz <device>
> 
> Filesystems seem to care about the physical block size only, not the logical block size.
> 
> So as soon as you have PVs with different physical block sizes (as reported by blockdev --getpbsz) I would be very careful...

Hello everybody.
Maybe, I don’t understand what do you mean. What the logical block size
mean? But on my machines(CentOS7), this utility get me the strange
results (output reduced):

 smartctl -i /dev/sda; blockdev --getbsz --getpbsz /dev/sda
Device Model:     INTEL SSDSC2KB480G8
User Capacity:    480,103,981,056 bytes [480 GB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    Solid State Device
4096
4096

 smartctl -i /dev/sdb; blockdev --getbsz --getpbsz /dev/sdb
Device Model:     HGST HUS722T2TALA604
User Capacity:    2,000,398,934,016 bytes [2.00 TB]
Sector Size:      512 bytes logical/physical
Rotation Rate:    7200 rpm
Form Factor:      3.5 inches
4096
512

As you see “–getbsz” forever 4096.
But I think it must be forever 512.
What does it mean?

Thank you.
Ilia.