When using wget for mirroring large files across servers, many users encounter the frustrating "Cannot write to" error that terminates downloads prematurely. This typically occurs when:

wget -x -N -i http://domain.com/filelist.txt

• File sizes exceed 2GB (common with -N timestamping)
• Destination filesystem has space limitations
• Character encoding issues in terminal output
• Incomplete partial downloads causing verification failures

The problem stems from multiple technical factors interacting:

--2012-08-31 12:41:19--  http://domain.com/path/to/file.zip
Length: 5502192869 (5.1G) [application/zip]
Cannot write to âdomain.com/path/to/file.zipâ

Key observations from the error pattern:

1. Consistent failure around 200MB-3GB range
2. Character encoding artifacts (â symbols)
3. Timestamp verification conflicts with existing partial files

Option 1: Disable Timestamp Verification

For large files, temporarily omit -N flag:

wget -x -c -i http://domain.com/filelist.txt

The -c enables resuming interrupted downloads

Option 2: Filesystem Workarounds

# Create download directory with sufficient inodes
mkdir -p /data/downloads
chmod 1777 /data/downloads

# Mount with large file support
mount -o remount,rw,noatime,nodiratime /data

Option 3: Alternative Download Methods

For extremely large files, consider:

# Using curl with progress bar
curl -L -C - -o file.zip http://domain.com/path/to/file.zip

# Parallel download with aria2
aria2c -x16 -s16 http://domain.com/path/to/file.zip

The â symbols indicate terminal encoding mismatch. Force UTF-8:

LC_ALL=en_US.UTF-8 wget -x -N http://domain.com/path/to/file.zip

When standard solutions fail:

# Debug filesystem limits
df -h
df -i
ulimit -a

# Verify network stability
mtr --report domain.com

# Check for antivirus interference
systemctl stop clamav-daemon

• Implement download chunking for files >2GB
• Schedule transfers during low-traffic periods
• Monitor disk I/O during transfers (iotop -o)
• Consider using rsync for regular mirroring

# Sample rsync alternative
rsync -avz --partial --progress user@remote:/path/ /local/path/

---

When using wget to transfer large files (particularly those over 2GB), many developers encounter a frustrating scenario where downloads abruptly terminate with a "Cannot write to [filename]" error. This typically occurs after transferring approximately 200MB-3GB of data, regardless of the actual file size.

--2023-11-15 09:30:00--  http://example.com/large_file.iso
...
3% [====> ] 213,003,412 8.74M/s   in 24s
Cannot write to âexample.com/large_file.isoâ

Based on extensive troubleshooting, these are the most likely culprits:

• Filesystem limitations: The destination filesystem might have file size restrictions (common with FAT32's 4GB limit)
• Disk space issues: Insufficient space or quota restrictions
• Character encoding problems: The "â" characters in the error suggest encoding issues
• wget version limitations: Older versions may have large file handling bugs

Solution 1: Use wget's Continue Option

The most effective approach is to utilize wget's built-in resume capability:

wget -c -x -N http://domain.com/path/to/file.zip

Key flags:

• -c: Continue partial downloads
• -x: Preserve directory structure
• -N: Timestamping for new files only

Solution 2: Verify Filesystem Compatibility

Check your destination filesystem type and limitations:

df -Th /path/to/destination

For large files (>4GB), ensure you're using a modern filesystem like ext4, NTFS, or XFS.

Solution 3: Alternative Download Methods

If wget persists in failing, consider these alternatives:

# Using curl
curl -O -C - http://domain.com/path/to/file.zip

# Using rsync (if supported)
rsync -avzP user@remote:/path/to/file.zip /local/path/

For persistent cases, try these advanced techniques:

# 1. Specify output filename explicitly
wget -O /tmp/download_file.zip http://domain.com/path/to/file.zip

# 2. Force ASCII mode (for encoding issues)
wget --restrict-file-names=ascii -x -N http://domain.com/path/to/file.zip

# 3. Use newer wget version
wget --version
# Consider upgrading if below 1.20

• Always use -c flag for large downloads
• Monitor disk space with df -h before starting transfers
• Consider splitting large files when possible
• For scripts, implement error handling and retry logic

Here's a robust bash script to handle intermittent failures:

#!/bin/bash

MAX_RETRIES=5
RETRY_DELAY=30
URL="http://domain.com/path/to/file.zip"

for ((i=1; i<=$MAX_RETRIES; i++)); do
    wget -c -x -N "$URL"
    if [ $? -eq 0 ]; then
        echo "Download completed successfully"
        exit 0
    fi
    echo "Attempt $i failed. Retrying in $RETRY_DELAY seconds..."
    sleep $RETRY_DELAY
done

echo "Maximum retries reached. Download failed."
exit 1