When dealing with a production file-sharing server handling 3-5M page views daily, storage performance degradation becomes critical. In this case, we're observing:

• Disk capacity: 1.5TB SATA
• File count: ~250,000 files + thousands of symlinks
• Performance drop: From 80MB/s to 15-20MB/s (measured via hdparm)

While fsck can address filesystem inconsistencies, it may not directly solve the speed degradation. Common scenarios where fsck helps:

# Typical fsck command for ext4 filesystem
sudo fsck -C -y /dev/sdX

However, before running fsck, consider these diagnostics first:

# Check SMART status
sudo smartctl -a /dev/sdX

# Check for bad blocks
sudo badblocks -v /dev/sdX > bad-blocks.txt

For a 1.5TB drive with 250K files, expect approximately:

• Quick pass: 2-4 hours (if using journal replay)
• Full check: 6-12 hours (depending on CPU and disk health)

To simulate fsck timing without downtime:

# Dry run estimation
sudo touch /forcefsck
sudo tune2fs -c 1 /dev/sdX

For minimal downtime, consider:

1. LVM snapshots for offline checking
2. Staggered fsck using batch mode

Example LVM workflow:

# Create snapshot
sudo lvcreate -L 10G -s -n snap_root /dev/vg00/lv_root

# Check snapshot
sudo fsck -n /dev/vg00/snap_root

# If clean, schedule live check during low traffic
sudo fsck -p /dev/sdX

After fsck completes, implement these optimizations:

# Adjust filesystem parameters
sudo tune2fs -o journal_data_writeback /dev/sdX
sudo tune2fs -m 1 /dev/sdX

# Enable write caching (if UPS exists)
sudo hdparm -W1 /dev/sdX

When dealing with a high-traffic file-sharing website serving 3-5 million page views daily, disk performance becomes critical. Our case involves a 1.5TB SATA disk containing approximately 250,000 files and several thousand symbolic links. Performance metrics showed a significant drop from 80 MB/s to just 15-20 MB/s, as measured by hdparm.

While fsck (file system consistency check) is primarily designed to repair filesystem inconsistencies, it can sometimes improve performance by:

• Fixing corrupted inodes that might cause I/O bottlenecks
• Removing orphaned files that consume disk space
• Repairing directory structures that may slow down file access

However, fsck won't address hardware-level performance degradation or filesystem fragmentation (for non-ext4 filesystems).

The time required for fsck depends on multiple factors:

# Basic fsck command for ext4 filesystem
fsck -y /dev/sdX

For a 1.5TB drive with 250K files, expect:

• Phase 1 (Checking inodes, blocks, sizes): 1-2 hours
• Phase 2 (Checking directory structure): 30-60 minutes
• Phase 3 (Checking directory connectivity): 15-30 minutes
• Phase 4 (Reference counts): 30-45 minutes
• Phase 5 (Checking group summary info): 15-30 minutes

Total estimated time: 2.5-4.5 hours for a thorough check.

To minimize downtime:

# Use parallel checking (ext4 only)
fsck -fp -C 0 /dev/sdX

# For pre-mount checks (if possible)
touch /forcefsck
reboot

Before running fsck, consider these diagnostics:

# Check disk health
smartctl -a /dev/sdX

# Check for bad blocks
badblocks -sv /dev/sdX

# Measure actual throughput
hdparm -tT /dev/sdX

After completing fsck:

1. Monitor disk performance with iostat -x 1
2. Consider implementing a regular fsck schedule
3. Evaluate upgrading to SSDs for high-I/O workloads