A Linux engineer receives the following notification from a system:cp: cannot create regular file '/app/appdata.

The error "No space left on device" usually means either disk space or inodes are exhausted.

Checking the disk space (df -h), we see only 6.1MB is used, meaning there is plenty of free space (1.9GB available).

Checking inodes (df -i), we see all 2048 inodes are used (IUsed = 2048, IFree = 0), meaning no new files can be created even though space is available.

Inodes are metadata structures used to track files. Small files or a large number of directories can exhaust inodes before disk space runs out.

Fixing the Issue:

Remove unnecessary small files to free inodes:find /app -type f -exec rm -f {} +

Remove unnecessary small files to free inodes:find /app -type f -exec rm -f {} +

Remove unnecessary small files to free inodes:find /app -type f -exec rm -f {} +

Recreate the filesystem with a higher inode count:bashmkfs.ext4 -N 500000 /dev/vdb

Recreate the filesystem with a higher inode count:bashmkfs.ext4 -N 500000 /dev/vdb

Recreate the filesystem with a higher inode count:bashmkfs.ext4 -N 500000 /dev/vdb

Recreate the filesystem with a higher inode count:bashmkfs.ext4 -N 500000 /dev/vdb