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Friday, January 27, 2012

Changing the disk-naming scheme

You can either use enclosure-based naming for disks or the operating system’s naming scheme. VxVM commands display device names according the current naming scheme.
The default naming scheme is enclosure-based naming (EBN). When you install or upgrade a Storage Foundation product, the naming scheme is set to enclosure-based naming, with the following exception. If you explicitly set the naming scheme for an existing installation to operating system-based naming, the setting is preserved when you upgrade. That is, if you used the vxddladm set namingscheme=osn command for the existing installation, the upgraded 5.1 product retains the operating system-based naming.

To change the disk-naming scheme

Select Change the disk naming scheme 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.
Alternatively, you can change the naming scheme from the command line. Use the following command to select enclosure-based naming:

# vxddladm set namingscheme=ebn [persistence={yes|no}] \

[use_avid=yes|no] [lowercase=yes|no]
Use the following command to select operating system-based naming:

# vxddladm set namingscheme=osn [persistence={yes|no}] \

[lowercase=yes|no]
The optional persistence argument allows you to select whether the names of disk devices that are displayed by VxVM remain unchanged after disk hardware has been reconfigured and the system rebooted. By default, enclosure-based naming is persistent. Operating system-based naming is not persistent by default.

By default, the names of the enclosure are converted to lowercase, regardless of the case of the name specified by the ASL. The enclosure-based device names are therefore in lower case. Set the lowercase=no option to suppress the conversion to lowercase.

For enclosure-based naming, the use_avid option specifies whether the Array Volume ID is used for the index number in the device name. By default, use_avid=yes, indicating the devices are named as enclosure_avid. If use_avid is set to no, DMP devices are named as enclosure_index. The index number is assigned after the devices are sorted by LUN serial number.
The change is immediate whichever method you use.