xref: /freebsd/sys/contrib/openzfs/man/man5/vdev_id.conf.5 (revision 87bf66d4a7488c496af110d4d05cc0273d49f82e)
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11.Dd May 26, 2021
12.Dt VDEV_ID.CONF 5
13.Os
14.
15.Sh NAME
16.Nm vdev_id.conf
17.Nd configuration file for vdev_id(8)
18.Sh DESCRIPTION
19.Nm
20is the configuration file for
21.Xr vdev_id 8 .
22It controls the default behavior of
23.Xr vdev_id 8
24while it is mapping a disk device name to an alias.
25.Pp
26The
27.Nm
28file uses a simple format consisting of a keyword followed by one or
29more values on a single line.
30Any line not beginning with a recognized keyword is ignored.
31Comments may optionally begin with a hash character.
32.Pp
33The following keywords and values are used.
34.Bl -tag -width "-h"
35.It Sy alias Ar name Ar devlink
36Maps a device link in the
37.Pa /dev
38directory hierarchy to a new device name.
39The udev rule defining the device link must have run prior to
40.Xr vdev_id 8 .
41A defined alias takes precedence over a topology-derived name, but the
42two naming methods can otherwise coexist.
43For example, one might name drives in a JBOD with the
44.Sy sas_direct
45topology while naming an internal L2ARC device with an alias.
46.Pp
47.Ar name
48is the name of the link to the device that will by created under
49.Pa /dev/disk/by-vdev .
50.Pp
51.Ar devlink
52is the name of the device link that has already been
53defined by udev.
54This may be an absolute path or the base filename.
55.
56.It Sy channel [ Ns Ar pci_slot ] Ar port Ar name
57Maps a physical path to a channel name (typically representing a single
58disk enclosure).
59.
60.It Sy enclosure_symlinks Sy yes Ns | Ns Sy no
61Additionally create
62.Pa /dev/by-enclosure
63symlinks to the disk enclosure
64.Em sg
65devices using the naming scheme from
66.Pa vdev_id.conf .
67.Sy enclosure_symlinks
68is only allowed for
69.Sy sas_direct
70mode.
71.
72.It Sy enclosure_symlinks_prefix Ar prefix
73Specify the prefix for the enclosure symlinks in the form
74.Pa /dev/by-enclosure/ Ns Ao Ar prefix Ac Ns - Ns Ao Ar channel Ac Ns Aq Ar num
75.Pp
76Defaults to
77.Dq Em enc .
78.
79.It Sy slot Ar prefix Ar new Op Ar channel
80Maps a disk slot number as reported by the operating system to an
81alternative slot number.
82If the
83.Ar channel
84parameter is specified
85then the mapping is only applied to slots in the named channel,
86otherwise the mapping is applied to all channels.
87The first-specified
88.Ar slot
89rule that can match a slot takes precedence.
90Therefore a channel-specific mapping for a given slot should generally appear
91before a generic mapping for the same slot.
92In this way a custom mapping may be applied to a particular channel
93and a default mapping applied to the others.
94.
95.It Sy zpad_slot Ar digits
96Pad slot numbers with zeros to make them
97.Ar digits
98long, which can help to make disk names a consistent length and easier to sort.
99.
100.It Sy multipath Sy yes Ns | Ns Sy no
101Specifies whether
102.Xr vdev_id 8
103will handle only dm-multipath devices.
104If set to
105.Sy yes
106then
107.Xr vdev_id 8
108will examine the first running component disk of a dm-multipath
109device as provided by the driver command to determine the physical path.
110.
111.It Sy topology Sy sas_direct Ns | Ns Sy sas_switch Ns | Ns Sy scsi
112Identifies a physical topology that governs how physical paths are
113mapped to channels:
114.Bl -tag -compact -width "sas_direct and scsi"
115.It Sy sas_direct No and Sy scsi
116channels are uniquely identified by a PCI slot and HBA port number
117.It Sy sas_switch
118channels are uniquely identified by a SAS switch port number
119.El
120.
121.It Sy phys_per_port Ar num
122Specifies the number of PHY devices associated with a SAS HBA port or SAS
123switch port.
124.Xr vdev_id 8
125internally uses this value to determine which HBA or switch port a
126device is connected to.
127The default is
128.Sy 4 .
129.
130.It Sy slot Sy bay Ns | Ns Sy phy Ns | Ns Sy port Ns | Ns Sy id Ns | Ns Sy lun Ns | Ns Sy bay_lun Ns | Ns Sy ses
131Specifies from which element of a SAS identifier the slot number is
132taken.
133The default is
134.Sy bay :
135.Bl -tag -compact -width "port"
136.It Sy bay
137read the slot number from the bay identifier.
138.It Sy phy
139read the slot number from the phy identifier.
140.It Sy port
141use the SAS port as the slot number.
142.It Sy id
143use the scsi id as the slot number.
144.It Sy lun
145use the scsi lun as the slot number.
146.It Sy bay_lun
147read the slot number from the bay identifier and append the lun number.
148Useful for multi-lun multi-actuator hard drives.
149.It Sy ses
150use the SCSI Enclosure Services (SES) enclosure device slot number,
151as reported by
152.Xr sg_ses 8 .
153Intended for use only on systems where
154.Sy bay
155is unsupported,
156noting that
157.Sy port
158and
159.Sy id
160may be unstable across disk replacement.
161.El
162.El
163.
164.Sh FILES
165.Bl -tag -width "-v v"
166.It Pa /etc/zfs/vdev_id.conf
167The configuration file for
168.Xr vdev_id 8 .
169.El
170.
171.Sh EXAMPLES
172A non-multipath configuration with direct-attached SAS enclosures and an
173arbitrary slot re-mapping:
174.Bd -literal -compact -offset Ds
175multipath     no
176topology      sas_direct
177phys_per_port 4
178slot          bay
179
180#       PCI_SLOT HBA PORT  CHANNEL NAME
181channel 85:00.0  1         A
182channel 85:00.0  0         B
183channel 86:00.0  1         C
184channel 86:00.0  0         D
185
186# Custom mapping for Channel A
187
188#    Linux      Mapped
189#    Slot       Slot      Channel
190slot 1          7         A
191slot 2          10        A
192slot 3          3         A
193slot 4          6         A
194
195# Default mapping for B, C, and D
196
197slot 1          4
198slot 2          2
199slot 3          1
200slot 4          3
201.Ed
202.Pp
203A SAS-switch topology.
204Note, that the
205.Ar channel
206keyword takes only two arguments in this example:
207.Bd -literal -compact -offset Ds
208topology      sas_switch
209
210#       SWITCH PORT  CHANNEL NAME
211channel 1            A
212channel 2            B
213channel 3            C
214channel 4            D
215.Ed
216.Pp
217A multipath configuration.
218Note that channel names have multiple definitions - one per physical path:
219.Bd -literal -compact -offset Ds
220multipath yes
221
222#       PCI_SLOT HBA PORT  CHANNEL NAME
223channel 85:00.0  1         A
224channel 85:00.0  0         B
225channel 86:00.0  1         A
226channel 86:00.0  0         B
227.Ed
228.Pp
229A configuration with enclosure_symlinks enabled:
230.Bd -literal -compact -offset Ds
231multipath yes
232enclosure_symlinks yes
233
234#          PCI_ID      HBA PORT     CHANNEL NAME
235channel    05:00.0     1            U
236channel    05:00.0     0            L
237channel    06:00.0     1            U
238channel    06:00.0     0            L
239.Ed
240In addition to the disks symlinks, this configuration will create:
241.Bd -literal -compact -offset Ds
242/dev/by-enclosure/enc-L0
243/dev/by-enclosure/enc-L1
244/dev/by-enclosure/enc-U0
245/dev/by-enclosure/enc-U1
246.Ed
247.Pp
248A configuration using device link aliases:
249.Bd -literal -compact -offset Ds
250#     by-vdev
251#     name     fully qualified or base name of device link
252alias d1       /dev/disk/by-id/wwn-0x5000c5002de3b9ca
253alias d2       wwn-0x5000c5002def789e
254.Ed
255.
256.Sh SEE ALSO
257.Xr vdev_id 8
258