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SMB Read failure 1x weight estimate

SMB. operation timed out (Samba process hung or network overloaded)

SMB operation failed: timed out
Events
37
Pts per check
1.4
Pts missed
51.4
Teams hit
6/13

Authority mappings

Which work roles, knowledge units, and EWU courses this error pattern touches. Hover for context, click to drill in.

DCWF roles: CE-463 Host Analyst CS-462 Control Systems Security Specialist CS-521 Cyber Defense Infrastructure Support Specialist CS-531 Cyber Defense Incident Responder IT-411 Technical Support Specialist IT-451 System Administrator
Knowledge Units: CD-ISC IT Systems Components CD-OSA Operating Systems Administration CD-OSC Operating Systems Concepts
EWU courses: CSCD240-S26 CSCD210 CSCD212 CSCD240 CSCD327 CSCD380 CSCD470 CSCD496

What the message means

Samba accepted the TCP connection but did not respond in time. Usually means Samba is either deadlocked, out of resources, or the network path is severely congested. Restart is the fastest fix; investigate afterward.

Why the service is down

Commands in order

  1. 1. 1. Quick restart (buys ~60 seconds)
    systemctl restart smbd nmbd
    Expect
    No errors, both services active after restart
    Interpret and next
    If it hangs trying to stop: `killall -9 smbd nmbd ; systemctl start smbd nmbd`.
  2. 2. 2. Look for recent load spikes
    uptime ; free -h ; df -h
    Expect
    Load avg under CPU count; memory has free; /srv or wherever share lives NOT full
    Interpret and next
    Disk full = clear logs or snapshots to free space. Memory pressure = restart services.
  3. 3. 3. Check Samba logs for locks
    journalctl -u smbd -n 50 | tail -40
    Expect
    Normal auth/connect messages
    Interpret and next
    'waiting for lock' or 'oplock break timeout' = client holding a lock. Kill with smbstatus -L.
  4. 4. 4. See if someone is flooding 445
    ss -tn 'dport = :445' | wc -l ss -tn '( dport = :445 or sport = :445 )' | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -rn | head
    Expect
    Normal: a handful of connections; one dominant IP (scoring engine)
    Interpret and next
    Hundreds of connections from one non-scoring IP = attack. Firewall drop that IP.

Decision tree

Answer each question to route to the right fix.

Q: Does a plain `systemctl restart smbd` fix it (check scoreboard in 90s)?
Yes: Done. Add a watchdog to auto-restart if it happens again.
No:
Q: Is the host under high load?
Yes: Identify the cause of load (CPU, memory, disk). Kill offenders.
No: Likely an attack or upstream network issue. Firewall the noisy source.

External references

Other patterns on this service