vgscan.1m (2010 09)

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vgscan(1M) vgscan(1M)

NAME

vgscan - scan physical volumes for LVM volume groups

SYNOPSIS

/usr/sbin/vgscan

[-p][-v][

-a  -B  -k  -N  -C][-f

vg_names ...]

Remarks

If the volume group input arguments belong to a combination of volume groups version 1.0 and 2.0 or

higher, the arguments might not be processed in the order they are listed on the command line.

DESCRIPTION

The

vgscan command is used as follows:

1. Recovering and recreating the

/etc/lvmtab or /etc/lvmtab_p

ﬁle when the ﬁle has been

deleted or does not match the current physical volumes.

2. Reporting device special ﬁle lists for unconﬁgured volume groups.

For recovery,

vgscan will add entries for volume groups that are missing from

/etc/lvmtab or

/etc/lvmtab_p

. The vgscan command recovers volume group information by using LVM data struc-

tures in kernel memory, and by probing all devices, searching for LVM disks. If one or more physical

volumes in the volume group has more than 8 paths, the

vgscan command will only include 8 paths per

physical volume. Additional path(s) will not be added in the /etc/lvmtab or /etc/lvmtab_p

ﬁle.

The volume group device special ﬁle (

/dev/vg_name/group

) must be present for recovery to succeed.

In addition,

vgscan will recover a missing volume group only if it has been activated at least once since

the last boot or the last import, and the Volume Group ID is unique (see the WARNINGS section).

Unconﬁgured volume groups are volume groups residing on attached storage that are missing from

/etc/lvmtab or /etc/lvmtab_p and have not been activated since the last boot. The

vgscan com-

mand cannot recover the

/etc/lvmtab or /etc/lvmtab_p

entries for these volume groups. Instead,

it will print out the physical volume device special ﬁles for these volume groups. Conﬁgure these volume

groups using the

vgimport command. See vgimport (1M).

The

vgscan command will not update existing volume group entries in /etc/lvmtab or

/etc/lvmtab_p unless the -f

option is used. The -f option can be used to overwrite existing volume

group entries in

/etc/lvmtab or /etc/lvmtab_p

. Otherwise, /etc/lvmtab or /etc/lvmtab_p

should be moved before running vgscan, in order for the options to take full effect.

In HP-UX 11i Version 3, the Mass Storage Stack supports multiple naming conventions for the device

special ﬁles used to identify devices (see intro (7) and lvm(7)). Devices are represented as follows:

• Persistent device special ﬁles, (

/dev/disk/disk3).

• Cluster device special ﬁles, (

/dev/cdisk/disk3

• Legacy device special ﬁles, (

/dev/dsk/c0t6d6

LVM supports the use of all the three conventions within the same volume group.

The

vgscan command provides several options for controlling the use of legacy and persistent DSFs

(device special ﬁles) during the /etc/lvmtab or /etc/lvmtab_p recovery. By default, vgscan will

populate /etc/lvmtab or /etc/lvmtab_p with legacy DSFs, including alternate paths. There is one

exception:

For activated volume groups that are using persistent DSFs,

vgscan will populate /etc/lvmtab

or /etc/lvmtab_p using persistent DSFs for those physical volumes. The -N and -B options

allow the user to override this default behavior.

For volume groups that contained cluster DSFs,

vgscan will populate /etc/lvmtab or

/etc/lvmtab_p using the corresponding persistent DSFs for those pysical volumes.

Options and Arguments

vgscan recognizes the following options and arguments:

-a Scan all paths of multipathed physical volumes. The -a option cannot be used in

conjunction with the -k, -B, -C, and -N options and when the legacy naming

model is disabled with the rmsf -L command (see rmsf (1M)).

-B Populate /etc/lvmtab or /etc/lvmtab_p using both persistent and legacy

DSFs. Persistent DSFs will be added before legacy DSFs, so they will be used as the

primary path. This option can be used to migrate a deactivated volume group using

HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1

Summary of content (4 pages)

PAGE 1
vgscan(1M) vgscan(1M) NAME vgscan - scan physical volumes for LVM volume groups SYNOPSIS /usr/sbin/vgscan [-p] [-v] [-a  -B  -k  -N  -C] [-f vg_names ...] Remarks If the volume group input arguments belong to a combination of volume groups version 1.0 and 2.0 or higher, the arguments might not be processed in the order they are listed on the command line. DESCRIPTION The vgscan command is used as follows: 1.
PAGE 2
vgscan(1M) vgscan(1M) legacy DSFs to use both persistent and legacy DSFs. The -B option cannot be used in conjunction with the -a, -k, -C, and -N options and when the legacy naming model is disabled with the rmsf -L command (see rmsf (1M)). -C If a persistent DSF in a volume group has corresponding cluster DSFs, then the cluster DSF is printed on the left along with the existing persistent DSFs. The -C option requires the patch to Serviceguard A.11.
PAGE 3
vgscan(1M) vgscan(1M) EXAMPLES 1. Append entries for volume groups missing from the /etc/lvmtab or /etc/lvmtab_p file. For deactivated volume groups, use legacy DSFs, and for activated volume groups, use the DSFs that were used to activate them. Report all physical volume legacy DSFs belonging to unconfigured volume groups. Do not modify existing volume group entries in /etc/lvmtab or /etc/lvmtab_p. Run vgscan without any options: vgscan 2.
PAGE 4
vgscan(1M) vgscan(1M) mv /etc/lvmtab /etc/lvmtab.BCK or mv /etc/lvmtab_p /etc/lvmtab_p.BCK vgscan -f /dev/vg00 /dev/vg01 /dev/vg02 To preview the vgscan output for any of the above examples, include the -p and -v options in the command lines. WARNINGS The -N option may become obsolete in future releases. The -B option may become obsolete in future releases.