[ Previous | Next | Table of Contents | Index | Library Home |
Legal |
Search ]
Technical Reference: Base Operating System and Extensions, Volume 1
Queries a physical volume and
returns all pertinent information.
Logical Volume Manager Library
(liblvm.a)
#include <lvm.h>
int lvm_querypv (VG_ID, PV_ID, QueryPV, PVName)
struct unique_id * VG_ID;
struct unique_id * PV_ID;
struct querypv ** QueryPV;
char * PVName;
Note: You must
have root user authority to use the lvm_querypv subroutine.
The lvm_querypv
subroutine returns information on the physical volume specified by the
PV_ID parameter.
The querypv structure,
defined in the lvm.h file, contains the following
fields:
struct querypv {
long ppsize;
long pv_state;
long pp_count;
long alloc_ppcount;
struct pp_map *pp_map;
long pvnum_vgdas;
}
struct pp_map {
long pp_state;
struct lv_id lv_id;
long lp_num;
long copy;
struct unique_id fst_alt_vol;
long fst_alt_part;
struct unique_id snd_alt_vol;
long snd_alt_part;
}
Field
| Description
|
ppsize
| Specifies the size of the physical partitions, which is the same for all
partitions within a volume group. The size in bytes of a physical
partition is 2 to the power of ppsize.
|
pv_state
| Contains the current state of the physical volume.
|
pp_count
| Contains the total number of physical partitions on the physical
volume.
|
alloc_ppcount
| Contains the number of allocated physical partitions on the physical
volume.
|
pp_map
| Points to an array that has entries for each physical partition of the
physical volume. Each entry in this array will contain the
pp_state that specifies the state of the physical partition
(LVM_PPFREE, LVM_PPALLOC, or LVM_PPSTALE) and
the lv_id, field, the ID of the logical volume that it is a member
of. The pp_map array also contains the physical volume IDs
(fst_alt_vol and snd_alt_vol) and the physical partition
numbers (fst_alt_part and snd_alt_part) for
the first and second alternate copies of the physical partition, and the
logical partition number (lp_num) that the physical partition
corresponds to.
If the physical partition is free (that is, not allocated), all
of its pp_map fields will be zero.
- fst_alt_vol
- Contains zeros if the logical partition has only one physical copy.
- fst_alt_part
- Contains zeros if the logical partition has only one physical copy.
- snd_alt_vol
- Contains zeros if the logical partition has only one or two physical
copies.
- snd_alt_part
- Contains zeros if the logical partition has only one or two physical
copies.
- copy
- Specifies which copy of a logical partition this physical partition is
allocated to. This field will contain one of the following
values:
- LVM_PRIMARY
- Primary and only copy of a logical partition
- LVM_PRIMOF2
- Primary copy of a logical partition with two physical copies
- LVM_PRIMOF3
- Primary copy of a logical partition with three physical copies
- LVM_SCNDOF2
- Secondary copy of a logical partition with two physical copies
- LVM_SCNDOF3
- Secondary copy of a logical partition with three physical copies
- LVM_TERTOF3
- Tertiary copy of a logical partition with three physical copies.
-
-
|
pvnum_vgdas
| Contains the number of volume group descriptor areas (0,
1, or 2) that are on the specified physical volume.
|
The PVName parameter
enables the user to query from a volume group descriptor area on a specific
physical volume instead of from the Logical Volume Manager's (LVM) most
recent, in-memory copy of the descriptor area. This method should only
be used if the volume group is varied off. The data returned is not
guaranteed to be most recent or correct, and it can reflect a back level
descriptor area.
The PVname parameter
should specify either the full path name of the physical volume that contains
the descriptor area to query or a single file name that must reside in the
/dev directory (for example, rhdisk1). This field
must be a null-terminated string of from 1 to LVM_NAMESIZ bytes,
including the null byte, and represent a raw or character device. If a
raw or character device is not specified for the PVName parameter,
the LVM will add an r to the file name in order to have a raw
device name. If there is no raw device entry for this name, the LVM
will return the LVM_NOTCHARDEV error code. If a
PVName is specified, the volume group identifier, VG_ID,
will be returned by the LVM through the VG_ID parameter passed in
by the user. If the user wishes to query from the LVM in-memory copy,
the PVName parameter should be set to null. When using this
method of query, the volume group must be varied on, or an error will be
returned.
Note: As long as
the PVName is not null, the LVM will attempt a query from a
physical volume and not from its in-memory copy of data.
In addition to the
PVName parameter, the caller passes the VG_ID parameter,
indicating the volume group that contains the physical volume to be queried,
the unique ID of the physical volume to be queried, the PV_ID
parameter, and the address of a pointer of the type QueryPV.
The LVM will separately allocate enough space for the querypv
structure and the struct pp_map array and return the address of the
querypv structure in the QueryPV pointer passed
in. The user is responsible for freeing the space by freeing the struct
pp_map pointer and then freeing the QueryPV
pointer.
VG_ID
| Points to a unique_id structure that specifies the volume
group of which the physical volume to query is a member.
|
PV_ID
| Points to a unique_id structure that specifies the physical
volume to query.
|
QueryPV
| Specifies the address of a pointer to a querypv
structure.
|
PVName
| Names a physical volume from which to use the volume group descriptor
area for the query. This parameter can be null.
|
The lvm_querypv
subroutine returns a value of 0 upon successful completion.
If the lvm_querypv
subroutine fails it returns one of the following error codes:
LVM_ALLOCERR
| The routine cannot allocate enough space for a complete buffer.
|
LVM_INVALID_PARAM
| An invalid parameter was passed into the routine.
|
LVM_INV_DEVENT
| The device entry for the physical volume is invalid and cannot be checked
to determine if it is raw.
|
LVM_OFFLINE
| The volume group specified is offline and should be online.
|
If the query originates from the
varied-on volume group's current volume group descriptor area, one of the
following error codes may be returned:
LVM_DALVOPN
| The volume group reserved logical volume could not be opened.
|
LVM_MAPFBSY
| The volume group is currently locked because system management on the
volume group is being done by another process.
|
LVM_MAPFOPN
| The mapped file, which contains a copy of the volume group descriptor
area used for making changes to the volume group, could not be opened.
|
LVM_MAPFRDWR
| Either the mapped file could not be read, or it could not be
written.
|
If a physical volume name has
been passed, requesting that the query originate from a specific physical
volume, then one of the following error codes may be returned:
LVM_BADBBDIR
| The bad-block directory could not be read or written.
|
LVM_LVMRECERR
| The LVM record, which contains information about the volume group
descriptor area, could not be read.
|
LVM_NOPVVGDA
| There are no volume group descriptor areas on this physical
volume.
|
LVM_NOTCHARDEV
| A device is not a raw or character device.
|
LVM_NOTVGMEM
| The physical volume is not a member of a volume group.
|
LVM_PVDAREAD
| An error occurred while trying to read the volume group descriptor area
from the specified physical volume.
|
LVM_PVOPNERR
| The physical volume device could not be opened.
|
LVM_VGDA_BB
| A bad block was found in the volume group descriptor area located on the
physical volume that was specified for the query. Therefore, a query
cannot be done from the specified physical volume.
|
This subroutine is part of Base
Operating System (BOS) Runtime.
List of Logical
Volume Subroutines and Logical Volume Programming
Overview in AIX 5L Version 5.1 General Programming
Concepts: Writing and Debugging Programs.
[ Previous | Next | Table of Contents | Index |
Library Home |
Legal |
Search ]