Placing Disks Under VxVM Control

When you add a disk to a system that is running VxVM, you need to put the disk under VxVM control so that VxVM can control the space allocation on the disk. Unless another disk group is specified, VxVM places new disks in the default disk group, rootdg.

The method by which you place a disk under VxVM control depends on the circumstances:

If the disk is new, it must be initialized and placed under VxVM control. You can use the menu-based vxdiskadm utility to do this.
CAUTION: Initialization destroys existing data on disks.
If the disk is not needed immediately, it can be initialized (but not added to a disk group) and reserved for future use. To do this, enter none when asked to name a disk group. Do not confuse this type of "spare disk" with a hot-relocation spare disk.
If the disk was previously initialized for future use by VxVM, it can be reinitialized and placed under VxVM control.
If the disk was previously used for a file system, VxVM prompts you to confirm that you really want to destroy the file system.
If the disk was previously in use by the LVM subsystem, you can preserve existing data while still letting VxVM take control of the disk. This is accomplished using conversion. With conversion, the virtual layout of the data is fully converted to VxVM control (see the VERITAS Volume Manager Migration Guide).
If the disk was previously in use by the LVM subsystem, but you do not want to preserve the data on it, use the LVM command, pvremove, before attempting to initialize the disk for VxVM.
Multiple disks on one or more controllers can be placed under VxVM control simultaneously. Depending on the circumstances, all of the disks may not be processed the same way.
When initializing multiple disks at once, it is possible to exclude certain disks or controllers.
To exclude disks, list the names of the disks to be excluded in the file /etc/vx/disks.exclude before the initialization. The following is an example of the contents of a disks.exclude file:
c0t1d0
You can exclude all disks on specific controllers from initialization or encapsulation by listing those controllers in the file /etc/vx/cntrls.exclude. The following is an example of an entry in a cntrls.exclude file:
c0
You can exclude all disks in specific enclosures from initialization or encapsulation by listing those enclosures in the file /etc/vx/enclr.exclude. The following is an example of an entry in a enclr.exclude file:
enc1




	NOTE: Only the `vxinstall` and `vxdiskadm` commands use the contents of the `/etc/vx/disks.exclude`, `/etc/vx/cntrls.exclude` and `/etc/vx/enclr.exclude` files.

Installing and Formatting the Disk Media

Depending on the hardware capabilities of your disk media and of your system, you may either need to shut down and power off your system before installing the disk media, or you may be able to hot-insert the disk media into the live system. Many operating systems can detect the presence of the new disks on being rebooted. If the disks are inserted while the system is live, you may need to enter an operating system-specific command to notify the system.

If the disks require low- or intermediate-level formatting before use, use the operating system-specific formatting command to do this.

If the disks require low- or intermediate-level formatting before use, use the operating system-specific format command to do this.




	NOTE: SCSI disks are usually preformatted. Reformatting is needed only if the existing formatting has become damaged.

The following sections provide detailed examples of how to use the vxdiskadm utility to place disks under VxVM control in various ways and circumstances.

Placing Disks Under VxVM Control

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Installing and Formatting the Disk Media