nvme-commands-supported-effects · shipping · also NVMe Command Effects Log, NVMe log page 05h

NVMe Commands Supported and Effects

NVMe Commands Supported and Effects is log page 05h describing supported commands and their possible effects on subsystem state.

Related Observatory article: NVMe Commands Supported and Effects on hesela.com

Separate Admin and I/O opcode tables prevent confusing identical opcode values from different command sets. The I/O table depends on the selected command set. Entries describe possible effects, not execution history or proof of success. [1]

CSUPP indicates support. CSUPP=0 requires every other entry field to be zero; it does not describe a harmless supported command. LBCC concerns possible user-data changes; NCC covers one namespace's capabilities; NIC covers namespace count or multiple namespaces' capabilities; CCC covers controller capabilities. These are not observed change counters. [2]

Command Scope (CSP) is a bitmap. For CSUPP=1, CSP=0 means scope unreported, not absence of an affected entity. Multiple scope bits may be set when scope depends on command parameters. [1]

CSE recommends submission and execution restrictions. In Base 2.3, a recognized nonzero CSER supplies the relaxed recommendation instead; an unsupported CSER value leaves CSE applicable. CSER=01b recommends waiting for outstanding namespace-affecting Admin commands, then withholding further such commands until completion; this does not exclude all I/O. Base 2.0e reserves the later CSER bits. [2] [1]

Host behavior is implementation-specific. Linux v6.12 masks CSE for I/O commands and for Admin commands with nonzero CSER. When its passthrough path applies CSE, it freezes I/O across namespaces; NCC/NIC trigger a namespace rescan. This is not a universal driver guarantee. [3]

Relations

related

NVMe SMART log, NVMe Error Information Log, NVMe Format NVM, NVMe base specification

Limitations

• A capability-changing command can require refreshed Identify information; hosts associated with controllers to which the namespace is attached should coordinate their commands. [1]

Citations

1. NVM Express Base 2.0e, section 5.16.1.6, Figures 215-216. Copyright 2008-2024 NVM Express, Inc. All rights reserved. (accessed 2026-11-08)
2. NVM Express Base 2.3, Figure 214, pp. 221-222. Copyright 2008-2025 NVM Express, Inc. All rights reserved. (accessed 2026-11-08)
3. Linux v6.12, drivers/nvme/host/core.c: nvme_command_effects and nvme_passthru_start/end (accessed 2026-11-08)

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