vdev_id.conf - Configuration file for vdev_id
vdev_id.conf is the configuration file for
vdev_id(8). It controls
the default behavior of
vdev_id(8) while it is mapping a disk device
name to an alias.
The
vdev_id.conf file uses a simple format consisting of a keyword
followed by one or more values on a single line. Any line not beginning with a
recognized keyword is ignored. Comments may optionally begin with a hash
character.
The following keywords and values are used.
- alias <name> <devlink>
- Maps a device link in the /dev directory hierarchy to a new device name.
The udev rule defining the device link must have run prior to
vdev_id(8). A defined alias takes precedence over a
topology-derived name, but the two naming methods can otherwise coexist.
For example, one might name drives in a JBOD with the sas_direct topology
while naming an internal L2ARC device with an alias.
name - the name of the link to the device that will by created in
/dev/disk/by-vdev.
devlink - the name of the device link that has already been defined
by udev. This may be an absolute path or the base filename.
- channel [pci_slot] <port> <name>
- Maps a physical path to a channel name (typically representing a single
disk enclosure).
- enclosure_symlinks <yes|no>
- Additionally create /dev/by-enclosure symlinks to the disk enclosure sg
devices using the naming scheme from vdev_id.conf.
enclosure_symlinks is only allowed for sas_direct mode.
- enclosure_symlinks_prefix <prefix>
- Specify the prefix for the enclosure symlinks in the form of:
/dev/by-enclosure/<prefix>-<channel><num>
Defaults to "enc" if not specified.
- pci_slot - specifies the PCI SLOT of the HBA
- hosting the disk enclosure being mapped, as found in the output of
lspci(8). This argument is not used in sas_switch mode.
port - specifies the numeric identifier of the HBA or SAS switch
port connected to the disk enclosure being mapped.
name - specifies the name of the channel.
- slot <old> <new> [channel]
- Maps a disk slot number as reported by the operating system to an
alternative slot number. If the channel parameter is specified then
the mapping is only applied to slots in the named channel, otherwise the
mapping is applied to all channels. The first-specified slot rule
that can match a slot takes precedence. Therefore a channel-specific
mapping for a given slot should generally appear before a generic mapping
for the same slot. In this way a custom mapping may be applied to a
particular channel and a default mapping applied to the others.
- multipath <yes|no>
- Specifies whether vdev_id(8) will handle only dm-multipath devices.
If set to "yes" then vdev_id(8) will examine the first
running component disk of a dm-multipath device as listed by the
multipath(8) command to determine the physical path.
- topology <sas_direct|sas_switch>
- Identifies a physical topology that governs how physical paths are mapped
to channels.
sas_direct - in this mode a channel is uniquely identified by a PCI
slot and a HBA port number
sas_switch - in this mode a channel is uniquely identified by a SAS
switch port number
- phys_per_port <num>
- Specifies the number of PHY devices associated with a SAS HBA port or SAS
switch port. vdev_id(8) internally uses this value to determine
which HBA or switch port a device is connected to. The default is 4.
- slot <bay|phy|port|id|lun|ses>
- Specifies from which element of a SAS identifier the slot number is taken.
The default is bay.
bay - read the slot number from the bay identifier.
phy - read the slot number from the phy identifier.
port - use the SAS port as the slot number.
id - use the scsi id as the slot number.
lun - use the scsi lun as the slot number.
ses - use the SCSI Enclosure Services (SES) enclosure device slot
number, as reported by sg_ses(8). This is intended for use only on
systems where bay is unsupported, noting that port and
id may be unstable across disk replacement.
A non-multipath configuration with direct-attached SAS enclosures and an
arbitrary slot re-mapping.
multipath no
topology sas_direct
phys_per_port 4
slot bay
# PCI_SLOT HBA PORT CHANNEL NAME
channel 85:00.0 1 A
channel 85:00.0 0 B
channel 86:00.0 1 C
channel 86:00.0 0 D
# Custom mapping for Channel A
# Linux Mapped
# Slot Slot Channel
slot 1 7 A
slot 2 10 A
slot 3 3 A
slot 4 6 A
# Default mapping for B, C, and D
slot 1 4
slot 2 2
slot 3 1
slot 4 3
A SAS-switch topology. Note that the
channel keyword takes only two
arguments in this example.
topology sas_switch
# SWITCH PORT CHANNEL NAME
channel 1 A
channel 2 B
channel 3 C
channel 4 D
A multipath configuration. Note that channel names have multiple definitions -
one per physical path.
multipath yes
# PCI_SLOT HBA PORT CHANNEL NAME
channel 85:00.0 1 A
channel 85:00.0 0 B
channel 86:00.0 1 A
channel 86:00.0 0 B
A configuration with enclosure_symlinks enabled.
multipath yes
enclosure_symlinks yes
# PCI_ID HBA PORT CHANNEL NAME
channel 05:00.0 1 U
channel 05:00.0 0 L
channel 06:00.0 1 U
channel 06:00.0 0 L
In addition to the disks symlinks, this configuration will create:
/dev/by-enclosure/enc-L0
/dev/by-enclosure/enc-L1
/dev/by-enclosure/enc-U0
/dev/by-enclosure/enc-U1
A configuration using device link aliases.
# by-vdev
# name fully qualified or base name of device link
alias d1 /dev/disk/by-id/wwn-0x5000c5002de3b9ca
alias d2 wwn-0x5000c5002def789e
- /etc/zfs/vdev_id.conf
- The configuration file for vdev_id(8).
vdev_id(8)