1DAXCTL-CREATE-DEVI(1) DAXCTL-CREATE-DEVI(1)
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6 daxctl-create-device - Create a devdax device
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9 daxctl create-device [<options>]
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12 • Creates dax0.1 with 4G of size
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14 # daxctl create-device -s 4G
15 [
16 {
17 "chardev":"dax0.1",
18 "size":4294967296,
19 "target_node":0,
20 "mode":"devdax"
21 }
22 ]
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24 • Creates devices with fully available size on all regions
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26 # daxctl create-device -u
27 [
28 {
29 "chardev":"dax0.1",
30 "size":"15.63 GiB (16.78 GB)",
31 "target_node":0,
32 "mode":"devdax"
33 },
34 {
35 "chardev":"dax1.1",
36 "size":"15.63 GiB (16.78 GB)",
37 "target_node":1,
38 "mode":"devdax"
39 }
40 ]
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42 • Creates dax0.1 with fully available size on region id 0
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44 # daxctl create-device -r 0 -u
45 {
46 "chardev":"dax0.1",
47 "size":"15.63 GiB (16.78 GB)",
48 "target_node":0,
49 "mode":"devdax"
50 }
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53 Creates dax device in devdax mode in dynamic regions. The resultant can
54 also be convereted to the system-ram mode which arranges for the dax
55 range to be hot-plugged into the system as regular memory.
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57 daxctl create-device expects that the BIOS or kernel defines a range in
58 the EFI memory map with EFI_MEMORY_SP. The resultant ranges mean that
59 it’s 100% capacity is reserved for applications.
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62 -r, --region=
63 Restrict the operation to devices belonging to the specified
64 region(s). A device-dax region is a contiguous range of memory that
65 hosts one or more /dev/daxX.Y devices, where X is the region id and
66 Y is the device instance id.
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68 -s, --size=
69 For regions that support dax device cretion, set the device size in
70 bytes. Otherwise it defaults to the maximum size specified by
71 region. This option supports the suffixes "k" or "K" for KiB, "m"
72 or "M" for MiB, "g" or "G" for GiB and "t" or "T" for TiB.
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74 The size must be a multiple of the region alignment.
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76 -a, --align
77 Applications that want to establish dax memory mappings with page
78 table entries greater than system base page size (4K on x86) need a
79 device that is sufficiently aligned. This defaults to 2M. Note that
80 "devdax" mode enforces all mappings to be aligned to this value,
81 i.e. it fails unaligned mapping attempts.
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83 --input
84 Applications that want to select ranges assigned to a device-dax
85 instance, or wanting to establish previously created devices, can
86 pass an input JSON file. The file option lets a user pass a JSON
87 object similar to the one listed with "daxctl list".
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89 The device name is not re-created, but if a "chardev" is passed in
90 the JSON file, it will use that to get the region id.
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92 Note that the JSON content in the file cannot be an array of
93 JSON objects but rather a single JSON object i.e. without the
94 array enclosing brackets.
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96 -u, --human
97 By default the command will output machine-friendly raw-integer
98 data. Instead, with this flag, numbers representing storage size
99 will be formatted as human readable strings with units, other
100 fields are converted to hexadecimal strings.
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102 -v, --verbose
103 Emit more debug messages
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106 Copyright © 2016 - 2022, Intel Corporation. License GPLv2: GNU GPL
107 version 2 http://gnu.org/licenses/gpl.html. This is free software: you
108 are free to change and redistribute it. There is NO WARRANTY, to the
109 extent permitted by law.
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112 linkdaxctl:daxctl-list[1],daxctl-reconfigure-device[1],daxctl-destroy-device[1]
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116 01/13/2023 DAXCTL-CREATE-DEVI(1)