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Diffstat (limited to 'Documentation/nvme-id-ns.txt')
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diff --git a/Documentation/nvme-id-ns.txt b/Documentation/nvme-id-ns.txt new file mode 100644 index 0000000..4b3c258 --- /dev/null +++ b/Documentation/nvme-id-ns.txt @@ -0,0 +1,144 @@ +nvme-id-ns(1) +============= + +NAME +---- +nvme-id-ns - Send NVMe Identify Namespace, return result and structure + +SYNOPSIS +-------- +[verse] +'nvme id-ns' <device> [-v | --vendor-specific] [-b | --raw-binary] + [--namespace-id=<nsid> | -n <nsid>] [-f | --force] + [--human-readable | -H] + [--output-format=<fmt> | -o <fmt>] + +DESCRIPTION +----------- +For the NVMe device given, sends an identify namespace command and +provides the result and returned structure. + +The <device> parameter is mandatory and may be either the NVMe character +device (ex: /dev/nvme0), or a namespace block device (ex: /dev/nvme0n1). +If the character device is given, the `'--namespace-id'` option is +mandatory, otherwise it will use the ns-id of the namespace for the block +device you opened. For block devices, the ns-id used can be overridden +with the same option. + +On success, the structure may be returned in one of several ways depending +on the option flags; the structure may be parsed by the program or the +raw buffer may be printed to stdout. + +OPTIONS +------- +-n <nsid>:: +--namespace-id=<nsid>:: + Retrieve the identify namespace structure for the given nsid. This + is required for the character devices, or overrides the block nsid + if given. + +-f:: +--force:: + Request controller return the identify namespace structure even + if the namespace is not attached to the controller. This is valid + only for controllers at or newer than revision 1.2. Controllers + at revision lower than this may interpret the command incorrectly. + +-b:: +--raw-binary:: + Print the raw buffer to stdout. Structure is not parsed by + program. This overrides the vendor specific and human readable options. + +-v:: +--vendor-specific:: + In addition to parsing known fields, this option will dump + the vendor specific region of the structure in hex with ascii + interpretation. + +-H:: +--human-readable:: + This option will parse and format many of the bit fields + into human-readable formats. + +-o <format>:: +--output-format=<format>:: + Set the reporting format to 'normal', 'json', or + 'binary'. Only one output format can be used at a time. + + + +EXAMPLES +-------- +* Has the program interpret the returned buffer and display the known +fields in a human readable format: ++ +------------ +# nvme id-ns /dev/nvme0n1 +------------ ++ + +* If using the character device or overriding namespace id: ++ +------------ +# nvme id-ns /dev/nvme0 -n 1 +# nvme id-ns /dev/nvme0n1 -n 1 +# nvme id-ns /dev/nvme0 --namespace-id=1 +------------ ++ + +* In addition to showing the known fields, have the program to display +the vendor unique field: ++ +------------ +# nvme id-ns /dev/nvme0n1 --vendor-specific +# nvme id-ns /dev/nvme0n1 -v +------------ ++ +The above will dump the \'vs' buffer in hex since it doesn't know how to +interpret it. + +* Have the program return the raw structure in binary: ++ +------------ +# nvme id-ns /dev/nvme0n1 --raw-binary > id_ns.raw +# nvme id-ns /dev/nvme0n1 -b > id_ns.raw +------------ ++ +It is probably a bad idea to not redirect stdout when using this mode. + +* Alternatively you may want to send the data to another program that +can parse the raw buffer. ++ +------------ +# nvme id-ns /dev/nvme0n1 --raw-binary | nvme_parse_id_ns +------------ ++ +The parse program in the above example can be a program that shows the +structure in a way you like. The following program is such an example +that will parse it and can accept the output through a pipe, `'|'`, +as shown in the above example, or you can `'cat'` a saved output buffer +to it. +------------ +/* File: nvme_parse_id_ns.c */ + +#include <linux/nvme.h> +#include <stdio.h> +#include <unistd.h> + +int main(int argc, char **argv) +{ + unsigned char buf[sizeof(struct nvme_id_ns)]; + struct nvme_id_ns *ns = (struct nvme_id_ns *)buf; + + if (read(STDIN_FILENO, buf, sizeof(buf))) + return 1; + + printf("nsze : %#llx\n", ns->nsze); + printf("ncap : %#llx\n", ns->ncap); + return 0; +} +------------ + +NVME +---- +Part of the nvme-user suite |