No parent snapshot found, will read all files

Getting Help
1

Hi guys

I am new to Restic but I already love it, so thanks for providing such a great tool!

Today, I have come across a bit a strange thing - “no parent snapshot found, will read all files”.

I have backup’ed this volume a few times and after the initial full full read/write, subsequent backups were always very quick because there were very few new files or file changes. So I was surprised to see a full read again. As far as I can remember, I am using exactly the same backup command because I have kept a log of it.

When the snapshot (with full read) was completed, I ran it straight again and this time, it worked perfectly, as in the past.

Here my setup:

  • Backup command: restic -r q:\backup\synology\DS backup y:\ –no-scan
  • Source machine: Windows 10
  • Source volume: Synology NAS mounted to the Windows 10 machine
  • Target machine: TrueNAS-13.0 on FreeBSD 13.1 mounted SMB to Windows 10 machine

I have to mention that I do NOT keep the TrueNAS server running all the time as I only need it 1-2 a week. That made me think if I have some –igonore-inode issue as described here.

Is my assumption correct

  • that this is likely caused by inconsistent inodes?
  • and would this be an acceptable workaround to always use the -ignore-inode parameter?

Thanks very much for your help.
Phil

2

Did some more testing. I have 4 shares from the Synology mounted on the Windows 10 PC.
The “no parent snapshot found, will read all files” happened with 2 of them, the other 2 were fine, the parent snapshot was found.

3

Do your backup command contain wildcards, by any chance?

4

Hi Martin

These are the commands I used for each share:

Didn’t work: restic -r q:\backup\synology\DS backup y:\ –no-scan

Didn’t work: restic -r q:\backup\synology\AF backup x:\ –no-scan

Worked ok: restic -r q:\backup\synology\franz backup U:\ –no-scan --exclude=U:$RECYCLE.BIN --exclude=“U:\System Volume Information”

Worked ok: restic -r q:\backup\synology\phil backup Z:\ –no-scan --exclude=Z:$RECYCLE.BIN --exclude=“Z:\System Volume Information”

5

First, it’s not about inodes or something like this - restic is simply not able to find a parent and therefore has to read all files.

From your backup commands: Could it be that lower-case drives do not work, but upper-case do work?

6

That could be a possibility. The thing that speaks against is that when I ran the same command right after I had run it for the first time, I did work with with exactly the same syntax. Why would it run fine the second time?

See the logs below:

C:\Program Files\Restic>restic -r q:\backup\synology\DS backup y:\ –no-scan
enter password for repository:
repository 09c82391 opened (version 2, compression level auto)
no parent snapshot found, will read all files
[0:00] 100.00% 6 / 6 index files loaded

Files: 13895 new, 0 changed, 0 unmodified
Dirs: 1498 new, 0 changed, 0 unmodified
Added to the repository: 158.863 MiB (154.054 MiB stored)

processed 13895 files, 146.638 GiB in 36:30
snapshot f480c7ad saved

C:\Program Files\Restic>restic -r q:\backup\synology\DS backup y:\ –no-scan
enter password for repository:
repository 09c82391 opened (version 2, compression level auto)
using parent snapshot f480c7ad
[0:00] 100.00% 7 / 7 index files loaded

Files: 0 new, 0 changed, 13895 unmodified
Dirs: 0 new, 0 changed, 1498 unmodified
Added to the repository: 0 B (0 B stored)

processed 13895 files, 146.638 GiB in 0:09
snapshot 4021f1a9 saved