Synology NAS Error Code 30: How to Fix It

Hard 2-4 hours (depending on volume size) High Severity Verified June 2026
Summarize with ChatGPTSummarize with ClaudeSummarize with Perplexity Add as Preferred Source on Google
Error Code
30
Brand
Synology
Product Type
nas
Severity
High
DIY Difficulty
Hard
Estimated Fix Time
2-4 hours (depending on volume size)
Synology NAS error code 30 means your DSM has detected Btrfs subvolume corruption. This can cause data loss or system instability. Follow these steps to diagnose and repair the issue, but back up your data first.
Ad

Tools You'll Need

How to Fix Error Code 30

  1. Back Up Important Data Immediately

    Do not skip this step. Data loss is possible during repairs.

  2. Run a File System Check via SSH

    This may take hours. Do not interrupt the process.

  3. Restart DSM and Verify Repair

  4. Use Synology's Repair Tool (if available)

    Ensure no other RAID rebuilds are in progress.

  5. Restore from Backup if Necessary

    Resetting will wipe settings. Data remains on volumes unless you choose to format.
Ad

When to Call a Professional

If you are not comfortable with SSH, or if the repair command fails and you cannot recover data, contact Synology Support or a data recovery specialist. Also if the volume is still corrupted after repair.

Frequently Asked Questions

What causes Synology DSM error code 30?
Error code 30 indicates Btrfs subvolume corruption, often due to unexpected power loss, disk failure, or firmware bugs.
Can I fix error code 30 without losing data?
Yes, in most cases the btrfs check --repair command can fix corruption without data loss, but you must back up first as a precaution.
How long does a Btrfs repair take on Synology?
It depends on volume size and corruption extent. Small volumes (1TB) may take 30-60 minutes; large volumes (10TB+) can take several hours.
Will error code 30 affect all my shared folders?
Yes, it affects the entire volume. Some folders may become inaccessible or read-only until repaired.
Should I replace my NAS drives if I see error code 30?
Not necessarily. First, check disk health via DSM (Storage Manager > HDD/SSD). Replace failing drives only if S.M.A.R.T. indicates problems.

Related Error Codes