LBA
LBA（Logic Block Address），字面含义是逻辑块地址。但实际是block的编号，并不正常理解的地址的概念。
SSD是以block来划分的，将整个磁盘以block（像512B，4K等）大小进行划分，编号从0开始到最后一个，假设n-1
也即LBA取值为[0, n-1]
root@cpu7:/home/cpu7# nvme id-ns /dev/nvme2n1p1 -H NVME Identify Namespace 1: nsze : 0x1bf1f72b0 ncap : 0x1bf1f72b0 nuse : 0x1bf1f72b0 nsfeat : 0x8 [4:4] : 0 NPWG, NPWA, NPDG, NPDA, and NOWS are Not Supported [2:2] : 0 Deallocated or Unwritten Logical Block error Not Supported [1:1] : 0 Namespace uses AWUN, AWUPF, and ACWU [0:0] : 0 Thin Provisioning Not Supported nlbaf : 4 flbas : 0 [4:4] : 0 Metadata Transferred in Separate Contiguous Buffer [3:0] : 0 Current LBA Format Selected mc : 0x3 [1:1] : 0x1 Metadata Pointer Supported [0:0] : 0x1 Metadata as Part of Extended Data LBA Supported dpc : 0xf [4:4] : 0 Protection Information Transferred as Last 8 Bytes of Metadata Not Supported [3:3] : 0x1 Protection Information Transferred as First 8 Bytes of Metadata Supported [2:2] : 0x1 Protection Information Type 3 Supported [1:1] : 0x1 Protection Information Type 2 Supported [0:0] : 0x1 Protection Information Type 1 Supported dps : 0 [3:3] : 0 Protection Information is Transferred as Last 8 Bytes of Metadata [2:0] : 0 Protection Information Disabled nmic : 0x1 [0:0] : 0x1 Namespace Multipath Capable rescap : 0x7f [6:6] : 0x1 Exclusive Access - All Registrants Supported [5:5] : 0x1 Write Exclusive - All Registrants Supported [4:4] : 0x1 Exclusive Access - Registrants Only Supported [3:3] : 0x1 Write Exclusive - Registrants Only Supported [2:2] : 0x1 Exclusive Access Supported [1:1] : 0x1 Write Exclusive Supported [0:0] : 0x1 Persist Through Power Loss Supported fpi : 0 [7:7] : 0 Format Progress Indicator Not Supported dlfeat : 0 [4:4] : 0 Guard Field of Deallocated Logical Blocks is set to 0xFFFF [3:3] : 0 Deallocate Bit in the Write Zeroes Command is Not Supported [2:0] : 0 Bytes Read From a Deallocated Logical Block and its Metadata are Not Reported nawun : 0 nawupf : 0 nacwu : 0 nabsn : 0 nabo : 0 nabspf : 0 noiob : 0 nvmcap : 3840755982336 nsattr : 0 nvmsetid: 0 anagrpid: 0 endgid : 0 nguid : 000000000000000138b19e73c8002549 eui64 : 38b19e73c8254901 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 LBA Format 2 : Metadata Size: 8 bytes - Data Size: 512 bytes - Relative Performance: 0x2 Good LBA Format 3 : Metadata Size: 8 bytes - Data Size: 4096 bytes - Relative Performance: 0 Best LBA Format 4 : Metadata Size: 64 bytes - Data Size: 4096 bytes - Relative Performance: 0x2 Good