libnvme(9) API Manual libnvme(9)

# [NAME](#NAME)

struct nvme\_underlying\_ns\_entry - Underlying Namespace Entry Data Structure

# [SYNOPSIS](#SYNOPSIS)

struct nvme\_underlying\_ns\_entry {  
**\_\_u8 unsnqn\[NVME\_NQN\_LENGTH];**  
**\_\_le32 nsid;**  
**\_\_le16 cntlid;**  
**\_\_u8 rsvd58\[56];**  
**\_\_le16 idx;**  
};

# [Members](#Members)

[unsnqn](#unsnqn)

Underlying NVM Subsystem NQN (UNSNQN)

[nsid](#nsid)

Namespace [Identifier (NSID)](/man/os/nvme-cli/Identifier.NSID) of the Underlying Namespace

[cntlid](#cntlid)

Controller ID (CNTLID) of a controller able to attach *nsid*

[rsvd58](#rsvd58)

Reserved

[idx](#idx)

Index (IDX) into the list of reportable Underlying Namespaces

struct nvme\_underlying\_ns\_entry October 2026

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