pvcreate

Initialize physical hard disk partitions as physical volumes.

Description

The pvcreate command is used to initialize physical hard disk partitions as physical volumes so they can be used by LVM.

Syntax

pvcreate(options)(parameters)

Options

-f: Force the creation of a physical volume without user confirmation;
-u: Specify the UUID of the device;
-y: Answer "yes" to all questions;
-Z: Whether to utilize the first 4 sectors.

Parameters

Physical Volume: Specifies the device file name corresponding to the physical volume to be created.

Examples

View disk information:

[root@localhost ~]# fdisk -l
Disk /dev/hda: 41.1 GB, 41174138880 bytes
255 heads, 63 sectors/track, 5005 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   id  System
/dev/hda1   *           1          13      104391   83  Linux
/dev/hda2              14        1288    10241437+  83  Linux
/dev/hda3            1289        1925     5116702+  83  Linux
/dev/hda4            1926        5005    24740100    5  Extended
/dev/hda5            1926        2052     1020096   82  Linux swap / Solaris
/dev/hda6            2053        2235     1469916   8e  Linux LVM
/dev/hda7            2236        2418     1469916   8e  Linux LVM
/dev/hda8            2419        2601     1469916   8e  Linux LVM
/dev/hda9            2602        2784     1469916   8e  Linux LVM

Check if any PVs exist on the system, then initialize /dev/hda6 to /dev/hda9 as PVs:

[root@localhost ~]# pvscan
No matching physical volumes found    # No PVs found!

Convert partitions 6-9 to PVs (note the use of curly braces):

[root@localhost ~]# pvcreate /dev/hda{6,7,8,9}
  Physical volume "/dev/hda6" successfully created
  Physical volume "/dev/hda7" successfully created
  Physical volume "/dev/hda8" successfully created
  Physical volume "/dev/hda9" successfully created

Display information for each PV and summary information for all PVs:

[root@localhost ~]# pvscan
  PV /dev/hda6         lvm2 [1.40 GB]
  PV /dev/hda7         lvm2 [1.40 GB]
  PV /dev/hda8         lvm2 [1.40 GB]
  PV /dev/hda9         lvm2 [1.40 GB]
  Total: 4 [5.61 GB] / in use: 0 [0   ] / in no VG: 4 [5.61 GB]

Display detailed information for each PV on the system:

[root@localhost ~]# pvdisplay
  "/dev/hda6" is a new physical volume of "1.40 GB"
  --- NEW Physical volume ---
  PV Name               /dev/hda6  # Actual partition name
  VG Name                          # Blank as it's not yet assigned to a VG
  PV Size               1.40 GB    # Capacity description
  Allocatable           NO         # Whether it has been allocated
  PE Size (KByte)       0          # Size of PE in this PV
  Total PE              0          # Total number of PEs
  free PE               0          # PEs not used by LVs
  Allocated PE          0          # Number of PEs still available for allocation
  PV UUID               Z13Jk5-RCls-UJ8B-HzDa-Gesn-atku-rf2biN
....(remainder omitted)....

Remove a physical volume:

[root@localhost ~]# pvremove /dev/sdb2
Labels on physical volume "/dev/sdb2" successfully wiped

Modify physical volume attributes:

[root@localhost ~]# pvchange -x n /dev/sdb1    # Prohibit allocation of PEs on specified physical volume
Physical volume "/dev/sdb1" changed  
1 physical volume changed / 0 physical volumes not changed