vdev_id.conf(5)

NAME
vdev_id.conf - Configuration file for vdev_id

DESCRIPTION
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). 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>
    Maps a disk slot number as reported by the operating system to an alternative slot number.

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.

EXAMPLES
A non-multipath configuration with direct-attached SAS enclosures and an arbitrary slot re-mapping.

    multipath no
    topology sas_direct
    phys_per_port 4
    # 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
    # Linux Mapped
    # Slot Slot
    slot 1 7
    slot 2 10
    slot 3 3
    slot 4 6
    slot 5 2
    slot 6 8
    slot 7 1
    slot 8 4
    slot 9 9
    slot 10 5

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 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

FILES

/etc/zfs/vdev_id.conf
    The configuration file for vdev_id(8).

SEE ALSO
vdev_id(8)