Note Devices with very long device names (for example, Fibre Channel devices that include worldwide name (WWN) identifiers) are always represented by enclosure-based names. The operation in this section has no effect on such devices.
You can either use enclosure-based naming for disks or the operating system's naming scheme (such as c#t#d#). Select menu item 20 from the vxdiskadm main menu to change the disk-naming scheme that you want VxVM to use. When prompted, enter y to change the naming scheme. This restarts the vxconfig daemon to bring the new disk naming scheme into effect.
# vxddladm set namingscheme=ebn
# vxddladm set namingscheme=osn
Note This feature is available only if the default disk-naming scheme is set to use operating system-based naming, and the TPD-controlled enclosure does not contain fabric disks.
For disk enclosures that are controlled by third-party drivers (TPD) whose coexistence is supported by an appropriate ASL, the default behavior is to assign device names that are based on the TPD-assigned node names. You can use the vxdmpadm command to switch between these names and the device names that are known to the operating system:
# vxdmpadm setattr enclosure enclosure tpdmode=native|pseudo
# vxdisk list
DEVICE TYPE DISK GROUP STATUS
emcpower10 auto:hpdisk disk1 mydg online
emcpower11 auto:hpdisk disk2 mydg online
emcpower12 auto:hpdisk disk3 mydg online
emcpower13 auto:hpdisk disk4 mydg online
emcpower14 auto:hpdisk disk5 mydg online
emcpower15 auto:hpdisk disk6 mydg online
emcpower16 auto:hpdisk disk7 mydg online
emcpower17 auto:hpdisk disk8 mydg online
emcpower18 auto:hpdisk disk9 mydg online
emcpower19 auto:hpdisk disk10 mydg online
# vxdmpadm setattr enclosure EMC0 tpdmode=native
# vxdisk list
DEVICE TYPE DISK GROUP STATUS
c6t0d10 auto:hpdisk disk1 mydg online
c6t0d11 auto:hpdisk disk2 mydg online
c6t0d12 auto:hpdisk disk3 mydg online
c6t0d13 auto:hpdisk disk4 mydg online
c6t0d14 auto:hpdisk disk5 mydg online
c6t0d15 auto:hpdisk disk6 mydg online
c6t0d16 auto:hpdisk disk7 mydg online
c6t0d17 auto:hpdisk disk8 mydg online
c6t0d18 auto:hpdisk disk9 mydg online
c6t0d19 auto:hpdisk disk10 mydg online
If you enable enclosure-based naming, and use the vxprint command to display the structure of a volume, it shows enclosure-based disk device names (disk access names) rather than c#t#d# names. To discover the c#t#d# names that are associated with a given enclosure-based disk name, use either of the following commands:
# vxdisk list enclosure-based_name
# vxdmpadm getsubpaths dmpnodename=enclosure-based_name
# vxdisk list ENC0_21
# vxdmpadm getsubpaths dmpnodename=ENC0_21
The persistent device naming feature, introduced in VxVM 4.1, makes the names of disk devices persistent across system reboots. If operating system-based naming is selected, each disk name is usually set to the name of one of the paths to the disk. After hardware reconfiguration and a subsequent reboot, the operating system may generate different names for the paths to the disks. As DDL assigns persistent disk names using the persistent device name database that was generated during a previous boot session, the disk names may no longer correspond to the actual paths. This does not prevent the disks from being used, but the association between the disk name and one of its paths is lost.
# vxdmpadm getsubpaths dmpnodename=disk_access_name
# vxdisk list disk_access_name
If you change from c#t#d# based naming to enclosure-based naming, persistent simple or nopriv disks may be put in the "error" state and cause VxVM objects on those disks to fail. If this happens, use the following procedures to correct the problem:
These procedures use the vxdarestore utility to handle errors in persistent simple and nopriv disks that arise from changing to the enclosure-based naming scheme. You do not need to perform either procedure if the devices on which any simple or nopriv disks are present are not automatically configured by VxVM (for example, non-standard disk devices such as ramdisks).
Note The disk access records for simple disks are either persistent or non-persistent. The disk access record for a persistent simple disk is stored in the disk's private region. The disk access record for a non-persistent simple disk is automatically configured in memory at VxVM startup. A simple disk has a non-persistent disk access record if autoconfig is included in the flags field that is displayed by the vxdisk list disk_access_name command. If the autoconfig flag is not present, the disk access record is persistent. Nopriv disks are always persistent.
Note You cannot run vxdarestore if c#t#d# naming is in use. Additionally, vxdarestore does not handle failures on persistent simple/nopriv disks that are caused by renaming enclosures, by hardware reconfiguration that changes device names. or by removing support from the JBOD category for disks that belong to a particular vendor when enclosure-based naming is in use.
If all persistent simple and nopriv disks in the boot disk group (usually aliased as bootdg) go into the error state and the vxconfigd daemon is disabled after the naming scheme change, perform the following steps:
If an imported disk group other than bootdg, consisting only of persistent simple and/or nopriv disks, is put in the "online dgdisabled" state after the change to the enclosure-based naming scheme, perform the following steps: