fulldisk

Fulldisk is a term used to describe a storage device or partition that has reached its capacity, leaving little or no free space for new data. It is not a brand or single product, but a state reported by operating systems, storage systems, and applications when writes fail due to lack of space. In many interfaces and logs, a disk in this condition is labeled as full or as having no space left on device.

Causes and signs: Common causes include accumulation of large files, growth of log files and backups, frequent temporary files, and snapshots; insufficient capacity planning or failing to rotate logs and purge outdated data can contribute. Inodes can be exhausted even if there is some free space. Symptoms include error messages such as "No space left on device" or "Disk full" during file writes, failed backups, or stalled applications.

Impact and risks: A full disk can prevent new data from being saved, disrupt running services, cause application errors, and hamper system maintenance tasks like updates or log rotation. If critical system partitions fill up, the system may become unstable or unbootable in some cases.

Management and prevention: Monitor disk usage with system tools, set alerts at a safe threshold, and implement a routine cleanup policy. Use log rotation, archiving, or offloading to external storage; expand capacity or move data to larger volumes; review quotas and inode usage. Regularly identify large consumers of space and remove or relocate them as appropriate. When fulldisk is detected, prioritize stopping nonessential services to free space and reconfigure applications to write to alternate locations if possible.

See also: Disk space management, Disk quotas, Inodes, Log rotation, Data archiving.