The disk are configured with a 512k block size by default
```
root@cassandra03:/sys/block/nvme0n1/device# lsblk -o NAME,PHY-SeC | grep nvme
nvme0n1 512
├─nvme0n1p1 512
└─nvme0n1p9 512
nvme2n1 512
├─nvme2n1p1 512
└─nvme2n1p9 512
nvme1n1 512
├─nvme1n1p1 512
└─nvme1n1p9 512
nvme4n1 512
├─nvme4n1p1 512
└─nvme4n1p9 512
nvme3n1 512
├─nvme3n1p1 512
└─nvme3n1p9 512
```
They will have better performance with a 4k block size:
```
root@cassandra03:/sys/block/nvme0n1/device# ls /dev/nvme?n1 | xargs -t nvme id-ns -H | grep LBA
nvme id-ns -H /dev/nvme0n1 /dev/nvme1n1 /dev/nvme2n1 /dev/nvme3n1 /dev/nvme4n1
[3:0] : 0 Current LBA Format Selected
[0:0] : 0x1 Metadata as Part of Extended Data LBA Supported
LBA Format 0 : Metadata Size: 0 bytes - Data Size: 512 bytes - Relative Performance: 0x2 Good (in use)
LBA Format 1 : Metadata Size: 8 bytes - Data Size: 512 bytes - Relative Performance: 0x2 Good
LBA Format 2 : Metadata Size: 16 bytes - Data Size: 512 bytes - Relative Performance: 0x2 Good
LBA Format 3 : Metadata Size: 0 bytes - Data Size: 4096 bytes - Relative Performance: 0 Best
LBA Format 4 : Metadata Size: 8 bytes - Data Size: 4096 bytes - Relative Performance: 0 Best
LBA Format 5 : Metadata Size: 64 bytes - Data Size: 4096 bytes - Relative Performance: 0 Best
LBA Format 6 : Metadata Size: 128 bytes - Data Size: 4096 bytes - Relative Performance: 0 Best
root@cassandra03:/sys/block/nvme0n1/device# ls /dev/nvme?n1 | xargs -n1 -t nvme id-ns -H | grep LBA
nvme id-ns -H /dev/nvme0n1
[3:0] : 0 Current LBA Format Selected
[0:0] : 0x1 Metadata as Part of Extended Data LBA Supported
LBA Format 0 : Metadata Size: 0 bytes - Data Size: 512 bytes - Relative Performance: 0x2 Good (in use)
LBA Format 1 : Metadata Size: 8 bytes - Data Size: 512 bytes - Relative Performance: 0x2 Good
LBA Format 2 : Metadata Size: 16 bytes - Data Size: 512 bytes - Relative Performance: 0x2 Good
LBA Format 3 : Metadata Size: 0 bytes - Data Size: 4096 bytes - Relative Performance: 0 Best
LBA Format 4 : Metadata Size: 8 bytes - Data Size: 4096 bytes - Relative Performance: 0 Best
LBA Format 5 : Metadata Size: 64 bytes - Data Size: 4096 bytes - Relative Performance: 0 Best
LBA Format 6 : Metadata Size: 128 bytes - Data Size: 4096 bytes - Relative Performance: 0 Best
nvme id-ns -H /dev/nvme1n1
[3:0] : 0 Current LBA Format Selected
[0:0] : 0 Metadata as Part of Extended Data LBA Not Supported
LBA Format 0 : Metadata Size: 0 bytes - Data Size: 512 bytes - Relative Performance: 0x2 Good (in use)
LBA Format 1 : Metadata Size: 0 bytes - Data Size: 4096 bytes - Relative Performance: 0 Best
nvme id-ns -H /dev/nvme2n1
[3:0] : 0 Current LBA Format Selected
[0:0] : 0 Metadata as Part of Extended Data LBA Not Supported
LBA Format 0 : Metadata Size: 0 bytes - Data Size: 512 bytes - Relative Performance: 0x2 Good (in use)
LBA Format 1 : Metadata Size: 0 bytes - Data Size: 4096 bytes - Relative Performance: 0 Best
nvme id-ns -H /dev/nvme3n1
[3:0] : 0 Current LBA Format Selected
[0:0] : 0 Metadata as Part of Extended Data LBA Not Supported
LBA Format 0 : Metadata Size: 0 bytes - Data Size: 512 bytes - Relative Performance: 0x2 Good (in use)
LBA Format 1 : Metadata Size: 0 bytes - Data Size: 4096 bytes - Relative Performance: 0 Best
nvme id-ns -H /dev/nvme4n1
[3:0] : 0 Current LBA Format Selected
[0:0] : 0 Metadata as Part of Extended Data LBA Not Supported
LBA Format 0 : Metadata Size: 0 bytes - Data Size: 512 bytes - Relative Performance: 0x2 Good (in use)
LBA Format 1 : Metadata Size: 0 bytes - Data Size: 4096 bytes - Relative Performance: 0 Best
```
They can be reformated with this command [1] :
```
nvme format --lbaf=<lba format id> /dev/<device>
```
[1] from https://www.bjonnh.net/article/20210721_nvme4k/