libnvme(9) API Manual libnvme(9)

# [NAME](#NAME)

struct nvme\_registrant\_ext - Registrant Extended Data Structure

# [SYNOPSIS](#SYNOPSIS)

struct nvme\_registrant\_ext {  
**\_\_le16 cntlid;**  
**\_\_u8 rcsts;**  
**\_\_u8 rsvd3\[5];**  
**\_\_le64 rkey;**  
**\_\_u8 hostid\[16];**  
**\_\_u8 rsvd32\[32];**  
};

# [Members](#Members)

[cntlid](#cntlid)

Controller ID

[rcsts](#rcsts)

Reservation Status

[rsvd3](#rsvd3)

Reserved

[rkey](#rkey)

Reservation Key

[hostid](#hostid)

Host Identifier

[rsvd32](#rsvd32)

Reserved

struct nvme\_registrant\_ext October 2026

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Document: nvme_registrant_ext-libnvme3(2) from nvme-cli 3.2-r0 (Chainguard OS)
Source: https://github.com/linux-nvme/nvme-cli