Synology DS220j or DS220+ Red Light? Stop and Read This.
UK NAS recovery specialists since 2002. SHR, SHR-2, Btrfs, ext4. Free UK collection. Trusted by homes and small businesses across the UK.
What this means and what to do next
The Synology DS220j and DS220+ are two of the most popular two-bay home and small-office NAS units in the UK. Both support SHR (Synology Hybrid RAID) which, on a two-bay unit, operates as RAID 1 — mirroring your data across both disks so that either disk can fail without data loss. The red status light appears when that redundancy is lost: one disk has failed, the volume is degraded, or the volume cannot be mounted at all.
A red light is a warning, not a death sentence. In most cases, your data is still intact on at least one of the two disks. The question is what you do next. The instinctive response — replace the failed disk and click Repair — works when the surviving disk is completely healthy. But if the surviving disk has its own bad sectors (which becomes increasingly likely as drives age, particularly if both disks were bought and installed at the same time), the Repair process can fail mid-way, corrupting the filesystem on the surviving disk in the process. We see this sequence at least once a week.
The DS220j in particular uses Western Digital Red or Seagate IronWolf disks in most configurations, and both families have known failure patterns at the 3–5 year mark. If your DS220j is three or more years old and both drives were installed at the same time, the red light on one drive is a strong signal that the other drive should be treated with caution too.
The three most common DS220j / DS220+ red light scenarios
1. One disk failed, volume degraded — rebuild not yet attempted. The simplest scenario. DSM has marked one disk as failed and the volume is running in degraded mode (SHR RAID 1 with one disk). Your data is on the surviving disk. Don't replace the failed disk yet — image both disks first. Even the 'failed' disk usually has most of its data on it and is the most important source for reconstruction if anything goes wrong with the surviving disk during the rebuild. Get images, verify the surviving disk's health (SMART data), then decide on the rebuild.
2. Rebuild attempted and failed — volume now crashed or inaccessible. The most common scenario we handle. The user replaced the failed disk, clicked Repair, and midway through the rebuild the surviving disk hit unreadable sectors and the rebuild aborted. The volume is now offline and DSM shows it as 'Crashed'. The surviving disk still has most of its data on it, but its filesystem metadata may be in an inconsistent state from the interrupted rebuild. Recovery requires imaging all disks (including the originally-failed one) with specialist hardware and reconstructing the volume from the images.
3. Both disks failed simultaneously or volume corrupted by power loss. Less common but it does happen. A power cut during a write can corrupt the Btrfs metadata on the volume even when both disks are physically healthy. Symptoms: DSM boots, sees both drives, but shows the volume as crashed or unmountable. The disks are fine — the filesystem is damaged. Recovery typically requires Btrfs forensic analysis on images of both disks: walking the metadata trees, falling back to redundant copies, and extracting files. Recovery rates in this scenario are very high because the underlying data blocks are almost always intact.
How Data Clinic recovers a Synology DS220j or DS220+ after a red light
We image both disks individually before any other work begins — this is non-negotiable. Even if DSM says one disk is healthy, we image it before the rebuild because we've learned from experience that rebuilds stress surviving disks in ways that can cause a second failure. The imaging hardware (PC-3000 or Atola DiskSense) applies extended retry passes and hardware error correction to recover every readable sector. The original disks are then set aside untouched.
From the images, we first check the SHR metadata on both disks. For a two-bay SHR-1 unit running RAID 1, the recovery is essentially: find the most complete copy of the data and extract it from that. We mount the images read-only, run Btrfs or ext4 analysis tools (depending on your DSM version and format), and walk the filesystem to extract files. Most degraded-volume DS220j cases where the rebuild hasn't been attempted recover 100% of files.
For crashed volumes where a rebuild has been attempted, the work is more complex. We need to determine at what point the rebuild aborted and use the parity data that was correctly written alongside the original data for the unwritten sections. This forensic analysis takes longer but in the majority of cases still yields 95%+ recovery of files. Recovered data is returned on a new external drive of your choice, structured to match your original Synology share layout so you can continue working without reorganising. More about our NAS recovery service →.
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What our customers say
"Three years of family photos on a drive that suddenly failed. Data Clinic collected next day, kept me updated through the cleanroom work, and got everything back. Worth every penny."
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Frequently asked questions
DSM says one disk is healthy and the other failed. Is my data safe?
Safer than it looks, but not safe. The 'healthy' disk holds your data in its current state. But the 'healthy' disk is now under more stress than it has been for a long time, because it's being continuously accessed in degraded mode. If it's the same age as the failed disk (common in home NAS setups where both drives were bought together), its failure risk is elevated. Take the NAS offline, don't use it, and get it to us before the second disk follows the first.
Can I just pull the good disk and read it in a USB enclosure?
Possibly, for a quick sanity check. If the disk is a single large RAID 1 member, it may contain a readable Linux partition that you can access on a Linux system. But Windows and macOS can't read Btrfs natively, and the partition layout on a Synology disk (md-RAID metadata + LVM + Btrfs) is not directly readable by any desktop OS without specialist tools. For a full, verified recovery of all your files, bring both disks to us.
How much does DS220j data recovery cost in the UK?
Most two-disk NAS recoveries fall in our standard tier: typically £495–£995 including VAT depending on total capacity, the filesystem (Btrfs is slightly more complex than ext4), and whether a rebuild has been attempted. Free diagnosis. No fee if we cannot recover your data.
My DS220j is in warranty. Will WD / Seagate replace the failed drive?
Yes, under warranty WD Red and IronWolf drives are replaced by the manufacturer. But drive replacement is not data recovery — a replacement disk is empty, and the rebuild to that disk is the moment of highest risk for the surviving disk. Get a data recovery assessment before starting any rebuild on a drive that's under warranty, then use the warranty replacement to complete the rebuild once you know your data is safe.
Synology DS223, DS224+, DS220+, DS118, DS218 — same approach?
Yes. The recovery process is the same across all Synology NAS units running DSM 6 or DSM 7, regardless of model. The disk format (Btrfs or ext4), the RAID type (SHR-1, SHR-2, RAID 1, RAID 5, JBOD), and the number of bays all affect the specific reconstruction work but not the fundamental approach: image first, reconstruct virtually, extract files.
How long does DS220j data recovery take?
Standard turnaround is 5–10 working days from receipt of the disks. Two-disk RAID 1 cases with no rebuild attempts often complete in 3–5 days. Emergency 48–72 hour services are available — call 0800 151 2207 to discuss.