Controlling User Processes: Setting Soft and Hard Limits to Prevent Performance Degradation

On our Storage server in Stratos Datacenter we are having some issues where the nfsuser user is holding hundreds of processes, which is degrading the performance of the server. Therefore, we have a requirement to limit its maximum processes. Please set its maximum process limits as below:

a. soft limit = 1026

b. hard_limit = 2024

Solution

Step 1: Connect to Storage Server (ststor01)

ssh natasha@ststor01
# Password: Bl@kW

Step 2: Switch to root

sudo su -
# Password: Bl@kW

Step 3: Set limits for nfsuser

# Add soft limit
echo "nfsuser soft nproc 1026" >> /etc/security/limits.conf

# Add hard limit
echo "nfsuser hard nproc 2024" >> /etc/security/limits.conf

Step 4: Verify the configuration

# Check the limits.conf file
tail -5 /etc/security/limits.conf

# Verify limits are applied (new session required)
su - nfsuser -c "ulimit -u"
su - nfsuser -c "ulimit -u -H"

One-Line Command

echo 'Bl@kW' | ssh natasha@ststor01 "sudo -S bash -c 'echo \"nfsuser soft nproc 1026\" >> /etc/security/limits.conf && echo \"nfsuser hard nproc 2024\" >> /etc/security/limits.conf && tail -5 /etc/security/limits.conf && echo \"Soft: \$(su - nfsuser -c \"ulimit -u\")\" && echo \"Hard: \$(su - nfsuser -c \"ulimit -u -H\")\"'"

Step-by-Step Interactive Commands

# Connect to storage server
ssh natasha@ststor01
# Password: Bl@kW

# Become root
sudo su -
# Password: Bl@kW

# Check current limits
echo "=== Current limits for nfsuser ==="
su - nfsuser -c "ulimit -u"

# Add soft limit
echo "=== Adding soft limit 1026 ==="
echo "nfsuser soft nproc 1026" >> /etc/security/limits.conf

# Add hard limit
echo "=== Adding hard limit 2024 ==="
echo "nfsuser hard nproc 2024" >> /etc/security/limits.conf

# Verify entries
echo "=== /etc/security/limits.conf entries ==="
grep nfsuser /etc/security/limits.conf

# Verify new limits
echo "=== New soft limit ==="
su - nfsuser -c "ulimit -u"

echo "=== New hard limit ==="
su - nfsuser -c "ulimit -u -H"

# Exit
exit
exit

Expected Output

[root@ststor01 ~]# echo "nfsuser soft nproc 1026" >> /etc/security/limits.conf
[root@ststor01 ~]# echo "nfsuser hard nproc 2024" >> /etc/security/limits.conf

[root@ststor01 ~]# grep nfsuser /etc/security/limits.conf
nfsuser soft nproc 1026
nfsuser hard nproc 2024

[root@ststor01 ~]# su - nfsuser -c "ulimit -u"
1026

[root@ststor01 ~]# su - nfsuser -c "ulimit -u -H"
2024

Verification Commands

# Check limits.conf entries
grep nfsuser /etc/security/limits.conf

# Check soft limit
su - nfsuser -c "ulimit -u"

# Check hard limit
su - nfsuser -c "ulimit -u -H"

# Check all limits for nfsuser
su - nfsuser -c "ulimit -a"

Summary

✅ Soft limit: 1026 (nfsuser soft nproc 1026)
✅ Hard limit: 2024 (nfsuser hard nproc 2024)
✅ Configuration added to /etc/security/limits.conf
✅ Limits verified for nfsuser

The process limits for nfsuser have been successfully configured on the Storage server.

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