Pages from the fire

Synology

Last updated: 2025-11-22

I have a home server to backup and show our photos. I like the Synology devices (appliances, perhaps) for this purpose because they are

  1. Easy to setup
  2. Reasonably hands off
  3. Low power (The ones I chose)
  4. Run Linux (underneath)
  5. Have the apps I need

The Synology Photos application is adequate for backing up photos from our iPhones.

The Jellyfin server and front ends (for iPad) are spectacular and the Jellyfin server has a distribution for Synology.

Synology can also run Docker, though I have not tried that yet.

Additional apps

System partition getting full

This one was a head scratcher. I went to update my system but got the dreaded “There is insufficient system capacity for DSM updates” message.

None of the tips in the linked page in the knowledge center applied to me.

My system partition was indeed very full,

$ df -H
Filesystem         Size  Used Avail Use% Mounted on
/dev/md0           2.5G  2.3G   67M  98% /
devtmpfs           5.1G     0  5.1G   0% /dev
tmpfs              5.2G  250k  5.2G   1% /dev/shm
tmpfs              5.2G   19M  5.2G   1% /run
tmpfs              5.2G     0  5.2G   0% /sys/fs/cgroup
tmpfs              5.2G   30M  5.2G   1% /tmp
/dev/loop0          29M  786k   26M   4% /tmp/SynologyAuthService
/dev/vg1/volume_2  3.0T  2.1T  892G  70% /volume2

but with what?

For a more detailed break down I tried

sudo du -sh --exclude=volume* /* 2>/dev/null

The last command excludes the volume1,… shared folders that are not part of the system partition (Or so I thought.).

I scoured the interwebs and tried some troubleshooting tips.

I used the builtin synocleaner tool

sudo synocleaner --delete-all-core
sudo synocleaner --delete-log
sudo synocleaner --delete-journal

But it didn’t free up much space. I just didn’t have so much on my system partition, and packages that I installed (Jellyfin, Synology Photos) were well behaved and installed themselves outside the system volume.

Then I ran into this thread. The person claimed that /volumeUSB1 was carrying some intermediate data.

I was skeptical, but …

$ df -h /volumeUSB1
Filesystem      Size  Used Avail Use% Mounted on
/dev/md0        2.3G  2.2G   61M  98% /

Whaaaaaat? That is mounted on the system volume??

I looked into that folder. The folder and its contents appeared only when I ssh-ed into the server, not on the GUI File browser. The data appeared to be our family photos which were clearly on a different partition (/photos) which was mounted on the data volume.

Long story short, after doing some experiments to verify that this was indeed some kind of duplicate junk data and not somehow my real data, I blew away the folders there.

$ df -h /volumeUSB1
Filesystem      Size  Used Avail Use% Mounted on
/dev/md0        2.3G  1.4G  849M  62% /

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