1saveconfig.json(5) File Formats Manual saveconfig.json(5)
2
6 saveconfig.json - Saved configuration file for rtslib-fb and LIO kernel
7 target
8
10 /etc/target/saveconfig.json is the default location for storing the
11 configuration of the Linux kernel target, also known as LIO. Since the
12 target is in the kernel, tools like targetctl or targetcli must be used
13 to save and restore the configuration across reboots.
14 Generating or modifying this file by hand, or with other tools, is also
16 supported. This fills a gap for users whose needs are not met by the
17 targetcli configuration shell, who cannot use the rtslib Python
18 library, and yet also wish to avoid directly manipulating LIO's con‐
19 figfs interface.
20
22 The configuration file is in the "json" text format, which is both
23 human- and machine-readable. Its format is very closely modeled on the
24 layout and terminology that LIO uses. Attributes may be string, bool‐
25 ean, or numeric values. All sizes are expressed in bytes.
26
28 TOP LEVEL SUMMARY
29 storage_objects describes mappings of resources on the local machine
30 that can be used to emulate block devices.
31 fabric_modules describes settings for LIO fabrics -- the hardware or
33 software protocols that transport SCSI commands -- such as iSCSI or
34 Fibre Channel over Ethernet (FCoE).
35 targets describes the SCSI target endpoints that export storage objects
37 over a fabric.
38 storage_objects
40 All storage objects must contain name and plugin values. Each name must
41 be unique for all storage objects of its plugin type.
42 plugin must be one of: fileio, block, pscsi, or ramdisk.
44 Objects with plugin value of fileio must also contain dev, which is the
46 full path to the file that is backing the storage object. Optional
47 fileio attributes are wwn (string), write_back (boolean), and size
48 (number). If the file given in dev does not exist, then size must be
49 present, and a backing file of that size will be created.
50 Objects with plugin value of block must also contain dev, which is the
52 full path to the block device that is backing the storage object.
53 Optional block attributes are wwn (string), write_back (boolean), and
54 readonly (boolean).
55 Objects with plugin value of pscsi must also contain dev, which is the
57 full path to the SCSI device that is backing the storage object. There
58 are no optional attributes.
59 Objects with plugin value of ramdisk must also contain size (number),
61 which is the size in bytes of the ramdisk. Optional ramdisk attributes
62 are wwn (string), and nullio (boolean).
63 All storage object definitions may also contain an attributes object.
65 This contains LIO attribute values, all of which are also optional.
66 Please see LIO documentation for more information on these.
67 fabric_modules
70 This section is limited to setting discovery authentication settings
71 for fabrics that support it (currently just iscsi). Objects here should
72 contain name (e.g. "iscsi"), userid, password, mutual_userid, and
73 mutual_password string values.
74 targets
77 Target configuration is modeled on iSCSI, in which a named target can
78 contain multiple sub-configurations called Target Port Groups (TPGs).
79 LIO follows this model for describing configuration even for fabrics
80 that do not support TPGs.
81 Objects in targets contain just three attributes: wwn is the world-wide
83 name the target has been given. This may start with "iqn", or "naa",
84 for example. fabric is the name of the fabric module this target is
85 exported over. Allowed values for this depend on the system configura‐
86 tion, but examples include "iscsi", "loopback", and "tcm_fc". tpgs is
87 a list of objects describing 1 or more TPGs, described below.
88 tpgs
91 TPG object attributes are all optional. Values not supplied will be set
92 to default values. tag (number) allows the tpg tag to be specified.
93 enable (bool, default to true) allows the TPG to be disabled or
94 enabled. luns, portals, and node_acls contain further lists of
95 objects, descibed below. Finally, userid, password, mutual_userid, and
96 mutual_password allow main-phase authentication values to be set for
97 fabrics (like iSCSI) that support TPG-level authentication. (Please see
98 targetcli(8) for details on TPG versus ACL-based authentication.)
99 Finally, TPGs can also contain optional attributes and parameters
100 lists, see LIO documentation for more information.
101 luns
104 This list of objects maps storage objects to the TPG. index is a TPG-
105 unique number for the assignment, which may be used as the LU number
106 for fabrics that do not support ACL mappings. storage_object is a
107 string linking back to a storage object, of the format "/back‐
108 stores/<plugin>/<name>", where <plugin> and <name> correspond to a
109 storage object defined under storage_objects.
110 portals
113 Portals describe connection endpoints for iSCSI targets. Required val‐
114 ues are ip_address (string) and port (number). iser (boolean) is an
115 optional value to enable iSER. offload (boolean) is an optional value
116 to enable hardware offload.
117 node_acls
120 This contains information about explicit initiator LUN mappings.
121 node_wwn (string) must be present. Authentication may also be set on a
122 per-ACL basis with userid, password, mutual_userid, and mutual_pass‐
123 word, similar to TPGs. mapped_luns is a list of mapped luns, described
124 below. Finally, node_acls can contain an optional attributes list.
125 mapped_luns
128 Objects in mapped_luns contain three required attributes. write_pro‐
129 tect (boolean) sets the write-protect status of the mapped LUN.
130 tpg_lun (number) corresponds to an existing entry in the TPG's luns
131 list. index is the LU number that the mapped LUN will claim.
132
135 Since tools generate this file, one good way to understand its format
136 is to use a tool like targetcli to configure a target, then run save‐
137 config, and view the resulting json file.
138
140 targetcli(8), targetctl(8)
141
143 /etc/target/saveconfig.json
144
146 Man page written by Andy Grover <agrover@redhat.com>.
147
149 Report bugs via <targetcli-fb-devel@lists.fedorahosted.org>
150 or <https://github.com/open-iscsi/rtslib-fb/issues>
151 saveconfig.json(5)