Disabling A Path To A Physical Volume - HP -UX 11i Administrator's Manual

"/etc/lvmconf/vg01.conf.old"
Volume group "vg01" has been successfully changed.
6. Activate the volume group and verify the changes as follows:
# vgchange -a y vg01
Activated volume group
Volume group "vg01" has been successfully changed.
# vgcfgbackup vg01
Volume Group configuration for /dev/vg01 has been saved in
/etc/lvmconf/vg01.conf
# vgcfgrestore -l -v -n vg01
Volume Group Configuration information in "/etc/lvmconf/vg01.conf"
VG Name /dev/vg01
---- Physical volumes : 1 ----
PV
c2t1d0 Non-Boot 35566480
max_pv 6 max_pe 56828 max_lv 255

Disabling a Path to a Physical Volume

IMPORTANT:
not prevent diagnostics or an application from accessing the physical volume.
By default, the mass storage stack uses all the paths available to access a physical volume,
independently of the paths configured in LVM. Disabling a path in LVM does not prevent the native
multipathing from using that path. Use the scsimgr command to disable I/O along a path or to
disable the native multipathing.
You can temporarily disable LVM's use of one or all of the physical paths to a physical volume
using the pvchange command. Disabling a path, also known as detaching the link, causes LVM
to close that path to the device and stop using it. This can be useful if you want to guarantee that
a link is idle, such as when you are running diagnostics on an I/O card, replacing an I/O card,
or replacing the disk containing the physical volume.
Detaching a link to a physical volume is a temporary operation, not a permanent one. If you want
to permanently remove a link or physical volume from the volume group, use vgreduce instead,
as described in
To detach a link to a physical volume, use the -a option to pvchange. For example, to disable
the link through the device /dev/disk/disk33, enter the following command:
# pvchange -a n /dev/disk/disk33
If you are using LVM's alternate links for multipathed disks, each link uses a different legacy device
files. In that situation, to detach all links to a physical volume, use N as the argument to the -a
option:
# pvchange -a N /dev/dsk/c5t0d0
Detaching one or more links to a physical volume does not necessarily cause LVM to stop using
that physical volume entirely. If the detached link is the primary path to the device, LVM begins
using any available alternate link to it. LVM stops using the physical volume only when all the links
to it are detached.
If all the links to a device are detached, the associated physical volume becomes unavailable to
the volume group. The links remain associated with the volume group but LVM does not send any
I/O requests to the physical volume until it is reattached. This means that the data on that physical
volume becomes temporarily unavailable; consequently, you must make sure that any availability
requirements for that data can be satisfied by mirroring before you make the device unavailable
by detaching it.
Type Size (kb) Start (kb) PVkey
This procedure only disables LVM's use of the link. The pvchange command does
"Removing a Disk from a Volume Group" (page
2912 0
51).
Moving and Reconfiguring Your Disks 87