VERITAS Volume Manager 3.5 Administrator's Guide (September 2002)

Rootability

70 VERITAS Volume Manager Administrator’s Guide

VxVM Root Disk Volume Restrictions

Volumes on a bootable VxVM-root disk have the following conﬁguration restrictions:

◆ All volumes on the root disk must be in the rootdg disk group.

◆ The names of the volumes with entries in the LIF LABEL record must be standvol,

rootvol, swapvol, and dumpvol (if present). The names of the volumes for other

ﬁle systems on the root disk are generated by appending vol to the name of their

mount point under /.

◆ Any volume with an entry in the LIF LABEL record must be contiguous. It can have

only one subdisk, and it cannot span to another disk.

◆ Therootvol and swapvol volumes must have thespecialvolume usage types root

and swap respectively.

Root Disk Mirrors

All the volumeson a VxVMrootdiskmay bemirrored.The simplest wayto achieve thisis

to mirror the VxVM root disk onto an identically sized or larger physical disk. If a mirror

of the root disk must also be bootable, the restrictions listed in “Booting Root Volumes”

also apply to the mirror disk.

Note If you mirror only selected volumes on the rootdisk anduse spanningor stripingto

enhance performance, these mirrors are not bootable.

See “Setting up a VxVM Root Disk and Mirror” for details of how to create a mirror of a

VxVM root disk.

Booting Root Volumes

Note At boot time, the system ﬁrmware provides you with a short time period during

which you canmanually override the automaticboot processand select analternate

boot device. For information on how to boot your system from a device other than

the primary or alternate bootdevices, and how to change the primary and alternate

boot devices, see the HP-UX documentation and the boot(1M), pdc(1M) and

isl(1M) manual pages.

Before the kernel mounts the root ﬁle system, it determines if the boot disk is a rootable

VxVM disk.If itis such a disk, thekernel passescontrol to itsVxVM rootability code.This

code extracts the starting block number and length of the root and swap volumes from

the LIF LABEL record, builds temporary volume and disk conﬁguration objects for these