Growing a File System on a Logical Volume
To grow a file system on a logical volume, perform the following steps:
1. Make a new physical volume.
2. Extend the volume group that contains the logical volume with the file system you are growing to include the new physical volume.
3. Extend the logical volume to include the new physical volume.
4. Grow the file system.
*If you have sufficient unallocated space in the volume group, you can use that space to extend the logical volume instead of performing steps 1 and 2.
Striped Logical Volumes
When you write data to an LVM logical volume, the file system lays the data out across the underlying physical volumes. You can control the way the data is written to the physical volumes by creating a striped logical volume.
For large sequential reads and writes, this can improve the efficiency of the data I/O.Striping enhances performance by writing data to a predetermined number of physical volumes in round-robin fashion. With striping, I/O can be done in parallel. In some situations, this can result in near-linear performance gain for each additional physical volume in the stripe.
Logical Volume Backup
Metadata backups and archives are automatically created on every volume group and logical volume configuration change unless disabled in the lvm.conf file. By default, the metadata backup is stored in the /etc/lvm/backup file and the metadata archives are stored in the /etc/lvm/archive file.
How long the metadata archives stored in the /etc/lvm/archive file are kept and how many archive files are kept is determined by parameters you can set in the lvm.conf file. A daily system backup should include the contents of the /etc/lvm directory in the backup.
Note that a metadata backup does not back up the user and system data contained in the logical volumes. You can manually back up the metadata to the /etc/lvm/backup file with the vgcfgbackup command.
Logical Volume Creation Overview
The following is a summary of the steps to perform to create an LVM logical volume.
1. Initialize the partitions you will use for the LVM volume as physical volumes (this labels them).
2. Create a volume group.
3. Create a logical volume.
After creating the logical volume you can create and mount the file system.
