Disk, Memory and CPU: df, du, free, vmstat, iostat, the OOM Killer and the "Disk Full" Case
Deleting an open log file with rm does not free space; the process holds it, lsof +L1 shows it and truncate gives the space back. With a real case of Bookstore's log disk filling up, we show df, du and inodes, the available column and the page cache in free, the OOM killer and systemd's MemoryMax limit, reading the load average with the core count, and telling CPU from I/O waits with vmstat, pidstat and iostat.
14 Nov 2026
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16 min
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4
