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Janak Shrestha
Janak Shrestha

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Linux Backup Basics: Creating Uncompressed and Compressed Tar Archives of System Logs

#linux

The development team requires specific logs stored within the Nautilus storage server situated in the Stratos DC. Access the designated location on the server to retrieve the necessary logs. Further, perform below actions:

Create a tar archive named logs.tar (under natasha's home) of /var/log/ directory.

Now, create a compressed tar archive as well named logs.tar.gz (under natasha's home) of /var/log/ directory.

Solution

Step 1: Connect to Storage Server 

ssh natasha@ststor01
# Password: Bl@kW
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Step 2: Verify current state 

# Check what files exist
ls -la ~/logs* 2>/dev/null

# Check if /var/log directory exists
ls -ld /var/log
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Step 3: Create the tar archives 

# Create uncompressed tar archive (removing leading '/' from member names)
tar -cf /home/natasha/logs.tar -C / var/log

# Create compressed tar archive (gzip)
tar -czf /home/natasha/logs.tar.gz -C / var/log
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Step 4: Verify files created 

# Check files exist
ls -la /home/natasha/logs.tar /home/natasha/logs.tar.gz

# Check file sizes
du -h /home/natasha/logs.tar /home/natasha/logs.tar.gz

# Verify archive contents
tar -tf /home/natasha/logs.tar | head -10
tar -tzf /home/natasha/logs.tar.gz | head -10
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Corrected Commands

One-Line Command 

ssh natasha@ststor01 "sudo -S bash -c 'tar -cf /home/natasha/logs.tar -C / var/log && tar -czf /home/natasha/logs.tar.gz -C / var/log && ls -la /home/natasha/logs.tar*'"
# Password: Bl@kW
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Step-by-Step Interactive 

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

# Switch to root (if needed for permissions)
sudo su -
# Password: Bl@kW

# Remove any failed attempts
rm -f /home/natasha/logs.tar /home/natasha/logs.tar.gz

# Create uncompressed tar (using -C to avoid leading / warning)
echo "=== Creating logs.tar ==="
tar -cf /home/natasha/logs.tar -C / var/log

# Create compressed tar
echo "=== Creating logs.tar.gz ==="
tar -czf /home/natasha/logs.tar.gz -C / var/log

# Verify files
echo "=== Verification ==="
ls -la /home/natasha/logs.tar /home/natasha/logs.tar.gz

# Check contents
echo "=== logs.tar contents (first 5) ==="
tar -tf /home/natasha/logs.tar | head -5

echo "=== logs.tar.gz contents (first 5) ==="
tar -tzf /home/natasha/logs.tar.gz | head -5

# Check sizes
echo "=== File sizes ==="
du -h /home/natasha/logs.tar /home/natasha/logs.tar.gz

# Exit
exit
exit
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Expected Output 

[natasha@ststor01 ~]$ ls -la /home/natasha/logs*
ls: cannot access /home/natasha/logs*: No such file or directory

[natasha@ststor01 ~]$ tar -cf /home/natasha/logs.tar -C / var/log
[natasha@ststor01 ~]$ tar -czf /home/natasha/logs.tar.gz -C / var/log

[natasha@ststor01 ~]$ ls -la /home/natasha/logs*
-rw-r--r-- 1 natasha natasha 456789 Aug 27 10:00 /home/natasha/logs.tar
-rw-r--r-- 1 natasha natasha  98765 Aug 27 10:00 /home/natasha/logs.tar.gz

[natasha@ststor01 ~]$ tar -tf /home/natasha/logs.tar | head -5
var/log/
var/log/anaconda/
var/log/anaconda/anaconda.log
var/log/anaconda/syslog
var/log/anaconda/program.log
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Common Issues & Fixes

Issue 1: "tar: Removing leading / from member names"

Fix: Use -C / to change directory before archiving:

tar -cf /home/natasha/logs.tar -C / var/log
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Issue 2: Permission denied

Fix: Use sudo or become root:

sudo tar -cf /home/natasha/logs.tar -C / var/log
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Issue 3: File not in correct location

Fix: Use absolute path:

tar -cf /home/natasha/logs.tar -C / var/log
# NOT: tar -cf logs.tar /var/log/
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Verification Commands 

# 1. Check files exist
ls -la /home/natasha/logs.tar /home/natasha/logs.tar.gz

# 2. Check file sizes (compressed should be smaller)
du -h /home/natasha/logs.tar /home/natasha/logs.tar.gz

# 3. Verify archive integrity
tar -tf /home/natasha/logs.tar > /dev/null && echo "✓ logs.tar valid"
tar -tzf /home/natasha/logs.tar.gz > /dev/null && echo "✓ logs.tar.gz valid"

# 4. Count files in each archive
echo "Files in logs.tar: $(tar -tf /home/natasha/logs.tar | wc -l)"
echo "Files in logs.tar.gz: $(tar -tzf /home/natasha/logs.tar.gz | wc -l)"

# 5. Check owner and permissions
ls -la /home/natasha/logs.tar*
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Complete Script (Run from Jump Host) 

#!/bin/bash

echo "========================================="
echo "Creating tar archives on Storage Server"
echo "========================================="

ssh natasha@ststor01 << 'EOF'
echo 'Bl@kW' | sudo -S bash -c '
echo ""
echo "=== Cleaning up old files ==="
rm -f /home/natasha/logs.tar /home/natasha/logs.tar.gz

echo ""
echo "=== Creating logs.tar ==="
tar -cf /home/natasha/logs.tar -C / var/log

echo ""
echo "=== Creating logs.tar.gz ==="
tar -czf /home/natasha/logs.tar.gz -C / var/log

echo ""
echo "=== Verification ==="
ls -la /home/natasha/logs.tar /home/natasha/logs.tar.gz

echo ""
echo "=== File sizes ==="
du -h /home/natasha/logs.tar /home/natasha/logs.tar.gz

echo ""
echo "=== logs.tar contents (first 5) ==="
tar -tf /home/natasha/logs.tar | head -5

echo ""
echo "✅ Both tar archives created successfully!"
'
EOF
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Summary

  • ✅ logs.tar created in /home/natasha/
  • ✅ logs.tar.gz created in /home/natasha/
  • ✅ Both archives contain /var/log/ directory
  • ✅ Archives verified and accessible
  • ✅ Using -C / to avoid leading / warnings

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