How do I map Linux disks, partitions, logical volumes and mountpoints?
Storage names represent different layers: a disk may contain partitions, a partition may hold an LVM physical volume, and a logical volume may contain a filesystem. lsblk and findmnt help map those relationships. Device names are not a safe substitute for verified identity when changing storage.
Before you start
- An authorised SSH session on the Linux server.
Instructions
1. List block-device relationships
Use explicit columns so the relevant fields are visible. Some older util-linux versions use MOUNTPOINT instead of MOUNTPOINTS.
lsblk -o NAME,SIZE,TYPE,FSTYPE,MOUNTPOINTSRead the tree from the underlying disk to the mounted filesystem. A blank filesystem field does not mean a device is unused or safe to format.
2. Resolve the application’s actual mount
Query the directory the application writes to. Compare the source with the block tree and any encryption, RAID or volume-management layer.
findmnt -T /var -o TARGET,SOURCE,FSTYPE,OPTIONSReplace /var with the actual path. Network, overlay and bind mounts may need their own runtime or storage-server inspection.
Check the result
- The entire path from application directory to storage device or remote mount is understood before a resize, replacement or recovery action is proposed.
Troubleshooting
- A device appears more than once
- Complex device-mapper or multi-device relationships can legitimately repeat entries. Investigate the topology instead of assuming duplicate disks.
- The expected disk is absent
- Check provider attachment, kernel detection and permissions before attempting a rescan or configuration change.
Official references
Use the documentation for your installed version when a flag, service name or platform feature differs.