hesela.devLogical volume
A logical volume is a virtual block device whose address space is mapped to backing storage by a volume-management system.
An application-facing logical volume provides block addresses, not a file hierarchy. A filesystem, database or other application can use that device. In LVM2, PVs contribute extents to a VG, which supplies LVs. Special thin-pool and cache-pool LVs represent pools and cannot be used as ordinary block devices. [1] [4]
A thin LV's reported size is its exposed address range, which can exceed currently allocated backing space. It is separate from VG free extents, thin-pool headroom and filesystem free space. [2]
Growing an LV alone does not grow its filesystem. For ext2/3/4, resize2fs can shrink an unmounted filesystem and can expand a mounted one when supported. A coordinated tool may perform both layer changes, but support for one does not establish support for the other. [3]
Relations
- related
- Volume manager, LVM, Storage virtualization, Block storage, Thin provisioning, Thin pool, Physical volume (LVM), Volume group (LVM)