Appendix E. LVM Volume Group Metadata
--metadatacopies 0option of the
pvcreatecommand. Once you have selected the number of metadata copies the physical volume will contain, you cannot change that at a later point. Selecting 0 copies can result in faster updates on configuration changes. Note, however, that at all times every volume group must contain at least one physical volume with a metadata area (unless you are using the advanced configuration settings that allow you to store volume group metadata in a file system). If you intend to split the volume group in the future, every volume group needs at least one metadata copy.
--metadatasizeoption of the
pvcreatecommand. The default size may be too small for volume groups that contain physical volumes and logical volumes that number in the hundreds.
E.1. The Physical Volume Label
pvcreatecommand places the physical volume label in the 2nd 512-byte sector. This label can optionally be placed in any of the first four sectors, since the LVM tools that scan for a physical volume label check the first 4 sectors. The physical volume label begins with the string
- Physical volume UUID
- Size of block device in bytes
- NULL-terminated list of data area locations
- NULL-terminated lists of metadata area locations