Linux Runbooks
Disk full, memory pressure, high load, zombie processes, and boot failures.
25 scenarios · search and filter below, or jump via the quick nav.
No space left on device errors in application logs
top shows one process at 100% CPU
bind: Address already in use error on application startup
systemctl status <service> shows failed state
Permission denied when accessing a file or directory
sudo: <user> is not in the sudoers file. This incident will be reported.
swapon --show returns empty
Disk usage climbing steadily over days/weeks
No space left on device but df -h shows free space
df shows full disk but du shows less total usage
System is sluggish and unresponsive under load
dmesg shows Out of memory: Killed process <PID>
Cannot fork or Cannot allocate memory when trying to start new processes
ps shows processes with Z state (zombie)
systemctl stop <service> hangs for the full timeout
EMFILE: Too many open files error in application logs
Upgraded binary but the running process still shows old version
Scheduled cron jobs are not running at the expected time
fork: Cannot allocate memory even though free RAM is available
Read-only file system errors when writing
Application fails with Cannot allocate memory
top shows load average well above CPU core count
Cannot assign requested address errors when connecting out
Shutdown or reboot hangs for minutes before eventually completing
Processes stuck in D (uninterruptible sleep) state