I recently set up a Synology DS220+ NAS to back up my home PC wirelessly. The backup process runs smoothly until it hits around 99% completion, then it just stalls indefinitely. I've tried connecting both the NAS and my PC to a 5 GHz Wi-Fi network to improve speed and stability, but the issue persists. Restarting the NAS or the router temporarily fixes it, but the problem returns on the next backup attempt. Wired connections aren’t an option right now because my PC is in a room far from the router, and running Ethernet cables isn’t feasible. I’m hoping to get reliable, full backups over Wi-Fi without this annoying stall at the end. Has anyone encountered this with Synology devices? Are there specific settings or firmware updates that might resolve this? Also, could it be related to large file sizes or the backup software itself? Any suggestions on troubleshooting this or alternative wireless backup approaches would be appreciated.

It sounds like the stall right at 99% could be related to how the backup software handles the finalizing steps - sometimes it’s not just about transferring files but verifying or indexing them, which can get stuck if there’s a hiccup in communication over Wi-Fi. Even on 5 GHz, interference or slight packet loss can cause these stalls, especially if large files are involved. Have you checked if your Synology DSM and backup app are fully updated? Sometimes firmware updates fix these edge-case bugs. Also, you might want to try breaking your backup into smaller chunks or folders instead of one big job to see if that helps avoid the stall. Some users have had luck switching to Synology’s Hyper Backup with versioning enabled, which can be more stable for incremental backups over Wi-Fi. If you haven’t already, enabling SMB3 or tweaking the MTU size on your NAS network settings might improve stability too. Wireless is always a bit trickier for heavy backups, but these tweaks could help

On 02/27/2026 at 3:45 PM, justgamer said:

It sounds like the stall right at 99% could be related to how the backup software handles the finalizing steps - sometimes it’s not just about transferring files but verifying or indexing them, which can get stuck if there’s a hiccup in communication over Wi-Fi. Even on 5 GHz, interference or slight packet loss can cause these stalls, especially if large files are involved. Have you checked if your Synology DSM and backup app are fully updated? Sometimes firmware updates fix these edge-case bugs. Also, you might want to try breaking your backup into smaller chunks or folders instead of one big job to see if that helps avoid the stall. Some users have had luck switching to Synology’s Hyper Backup with versioning enabled, which can be more stable for incremental backups over Wi-Fi. If you haven’t already, enabling SMB3 or tweaking the MTU size on your NAS network settings might improve stability too. Wireless is always a bit trickier for heavy backups, but these tweaks could help

@justgamer, you’re probably onto something with the finalizing step causing the hang. I’ve seen Synology’s Hyper Backup stall near the end when it’s hashing or verifying data, and if the Wi-Fi connection drops even briefly, it can freeze the process. Since OP mentioned the stall happens consistently at 99%, it’s likely the software is waiting on a response that never comes.

One workaround I found helpful was enabling SMB 3.0 encryption on the NAS and PC’s shared folders, which sometimes improves stability on flaky Wi-Fi by reducing retransmissions. Also, checking the NAS logs for any error messages during that final stage might reveal if it’s a timeout or a specific file causing the issue.

Given the no-wired-connection constraint, maybe tweaking the backup schedule to run smaller incremental backups more frequently could reduce the load and avoid hitting that problematic final step with a huge batch of files. Just an idea to keep things moving smoothly