Synology: Fatal glibc error "cannot get entropy for arc4random"

[update-freak]

1. What is not working as documented?

After updating [240420] to the latest docker version [240531] I tried to index a specific folder which I recently added.
Then after it finished I recognised that I can not see these newly added pictures.
In the log I saw that it was skipped due to the problem: Fatal glibc error: cannot get entropy for arc4random.

I think it's related to an to old kernel version of my Synology NAS (Linux NAS 3.10.108 #64570).

2. How can we reproduce it?

Steps to reproduce the behavior:

0. Be sure to use a system with a kernel version of "Linux NAS 3.10.108 #64570" (or maybe even older)
1. Install the 240420 version on docker
2. Click on settings and try to index the pictures of a new added folder
3. See error "Fatal glibc error: cannot get entropy for arc4random" in the logs

3. What behavior do you expect?

No error

4. What could be the cause of your problem?

I think the root cause is a too old kernel version.
This has also been reported on other software: jlesage/docker-freefilesync#8 (comment), https://github.com/MatthewVance/unbound-docker/issues/147)

5. Can you provide us with example files for testing, error logs, or screenshots?

If needed I can add logs.

6. Which software versions do you use?

(a) PhotoPrism version: 240531
(b) Database Type & Version: ?
(c) Operating System Types & Versions: Linux -> DSM 7.2 from Synology NAS
(d) Browser Types & Versions: Chrome (current version)
(e) Ad Blockers, Browser Plugins, and/or Firewall Software: uBlockOrigin

7. On what kind of device is PhotoPrism installed?

Synology NAS DS716+

8. Do you use a Reverse Proxy, Firewall, VPN, or CDN?

Yes, reverse proxy

9. Docker-compose for installation

docker-compose.txt

[lastzero]

Thanks for reporting this! Unfortunately, there's probably not much we can do about it if your kernel is very old. Is 3.10 the kernel version you are using? If it's a different version, please let us know which one.

[update-freak]

yes, exactly. I checked with uname -a my version and got Linux NAS 3.10.108 #64570
Here (jlesage/docker-freefilesync#8 (comment)) for example getentropy() was removed as solution (maybe helps)

[rkmfl]

Like the OP, I'm also on Kernel 3.10.108, because I'm limited by Synology. This is the kernel being used with Synology's most recent DSM 7.2.xxx releases, there is no method to upgrade.

PhotoPrism continually crashes on my Synology system with the same error:
Fatal glibc error: cannot get entropy for arc4random

On PhotoPrism latest release: 240531-60b3a4628

Docker Compose:
(I have it limited to a single worker thread and dedicate 10 GB of RAM explicitly for PhotoPrism)

services:
  photoprism:
    deploy:
      resources:
        limits:
          memory: 10G

    image: photoprism/photoprism:latest

    restart: unless-stopped
    stop_grace_period: 10s

    depends_on:
      - mariadb
    security_opt:
      - seccomp:unconfined
      - apparmor:unconfined
    ports:
      - "2342:2342"

    working_dir: "/volume1/docker/photo-prism"

    volumes:
      - "/volume2/Media/Photos:/photoprism/originals"
      - "/volume1/docker/photo-prism:/photoprism/storage"

    environment:
      PHOTOPRISM_ADMIN_USER: "<<obfuscated>>"
      PHOTOPRISM_ADMIN_PASSWORD: "<<obfuscated>>"
      PHOTOPRISM_AUTH_MODE: "public"

      PHOTOPRISM_SITE_URL: "http://10.10.10.11:2342/"

      PHOTOPRISM_DISABLE_TLS: "false"
      PHOTOPRISM_DEFAULT_TLS: "true"

      PHOTOPRISM_ORIGINALS_LIMIT: 20
      PHOTOPRISM_WORKERS: 1
      PHOTOPRISM_RESAMPLE_UNCACHED: "false"
      PHOTOPRISM_THUMB_UNCACHED: "false"
      PHOTOPRISM_THUMB_SIZE: 1600
      PHOTOPRISM_THUMB_SIZE_UNCACHED: 1600
      PHOTOPRISM_JPEG_SIZE: 7680
      PHOTOPRISM_JPEG_QUALITY: 70
      PHOTOPRISM_DARKTABLE_PRESETS: "false"

      PHOTOPRISM_HTTP_COMPRESSION: "gzip"
      PHOTOPRISM_LOG_LEVEL: "info"
      PHOTOPRISM_READONLY: "false"
      PHOTOPRISM_EXPERIMENTAL: "false"
      PHOTOPRISM_DISABLE_CHOWN: "false"
      PHOTOPRISM_DISABLE_WEBDAV: "false"
      PHOTOPRISM_DISABLE_SETTINGS: "false"
      PHOTOPRISM_DISABLE_TENSORFLOW: "false"
      PHOTOPRISM_DISABLE_FACES: "false"
      PHOTOPRISM_DISABLE_CLASSIFICATION: "false"
      PHOTOPRISM_DISABLE_VECTORS: "false"
      PHOTOPRISM_DISABLE_RAW: "false"
      PHOTOPRISM_RAW_PRESETS: "false"
      PHOTOPRISM_SIDECAR_YAML: "true"
      PHOTOPRISM_SIDECAR_JSON: "false"
      PHOTOPRISM_THUMB_FILTER: "lanczos"

      PHOTOPRISM_BACKUP_ALBUMS: "true"
      PHOTOPRISM_BACKUP_DATABASE: "true"
      PHOTOPRISM_BACKUP_SCHEDULE: "0 8 * * 1"
      PHOTOPRISM_INDEX_SCHEDULE: "0 9 * * *"

      PHOTOPRISM_AUTO_INDEX: 300
      PHOTOPRISM_AUTO_IMPORT: -1
      PHOTOPRISM_DETECT_NSFW: "false"
      PHOTOPRISM_UPLOAD_NSFW: "true"

      PHOTOPRISM_DATABASE_DRIVER: "mysql"
      PHOTOPRISM_DATABASE_SERVER: "mariadb:3306"
      PHOTOPRISM_DATABASE_NAME: "<<obfuscated>>"
      PHOTOPRISM_DATABASE_USER: "<<obfuscated>>"
      PHOTOPRISM_DATABASE_PASSWORD: "<<obfuscated>>"
      PHOTOPRISM_SITE_CAPTION: "AI-Powered Photos App"
      PHOTOPRISM_SITE_DESCRIPTION: ""
      PHOTOPRISM_SITE_AUTHOR: ""

  mariadb:
    image: mariadb:11
    restart: unless-stopped
    stop_grace_period: 5s
    security_opt:
      - seccomp:unconfined
      - apparmor:unconfined
    command: --innodb-buffer-pool-size=512M --transaction-isolation=READ-COMMITTED --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci --max-connections=32 --innodb-rollback-on-timeout=OFF --innodb-lock-wait-timeout=120
    volumes:
      - "/volume1/docker/photo-prism/mysql"
    environment:
      MARIADB_AUTO_UPGRADE: "1"
      MARIADB_INITDB_SKIP_TZINFO: "1"
      MARIADB_DATABASE: "<<obfuscated>>"
      MARIADB_USER: "<<obfuscated>>"
      MARIADB_PASSWORD: "<<obfuscated>>"
      MARIADB_ROOT_PASSWORD: "<<obfuscated>>"

[trampas75]

I have just installed PhotoPrism on my Synology 716+ NAS with Portainer and Docker and have exactly the same error:
Fatal glibc error: cannot get entropy for arc4random

This is after successfully loading 479 of about 900 folders of mainly photos with some video.
I am on the same kernel 3.10.108 and have 8GB of memory and plenty of free disk space.
Any help appreciated, thanks.

[rkmfl]

glibc error: cannot get entropy for arc4random

In my post above, I was not able to find a solution. Instead I watched for an image where it continually crashed on the same image and deleted that specific image.

I did this for about a dozen images with problems (having to re-run and locate the image where it crashed every time).

After doing this, I was able to continue without the Fatal glibc error: cannot get entropy for arc4random error.

[trampas75]

Thanks for the fast reply. I think that I can wait for a new version of PhotoPrism to appear and then try again.
Regards.

[lastzero]

It might be caused by some software / tool written in C that we use as dependency. It would help a lot to know which files or file types are causing this (e.g. RAW images). If it's file format independent, then maybe disabling TensorFlow helps (see Feature Flags in our Getting Started guide when you navigate to Config Options). As a workaround you can downgrade to the version released in April 2024, which is based on an older Linux distribution (and glibc).

[lastzero]

If the new Ubuntu Linux release we now use as base image is causing this, then I would not expect this issue to go away with an update which might require an even newer kernel. While it's also not an option to ship outdated software to everyone for the sake of compatibility, we could provide a special image for Synology users or replace / disable the dependency that's causing this (unless it's a general issue with Ubuntu 24.04 or later).

[rkmfl]

It would help a lot to know which files or file types are causing this

I'll attach a sample image here that causes the problem.

If it's file format independent

I believe it is file format independent. I can't be 100 certain now, but I believe it occurred with both .PNG and .JPG's in my case.

maybe disabling TensorFlow helps

Yes, I considered this using docker compose yaml:
PHOTOPRISM_DISABLE_TENSORFLOW: "true"

However, I wondered whether disabling Tensorflow might eliminate some of the ML features of PhotoPrism, which to me are the most important features.

Thank you.

[trampas75]

Looking at the log I tried deleting images and restarting indexing a few times all from the same folder. In the end I deleted the whole folder which was from my old OnePlus Nord mobile phone, mainly jpgs. So far PhotoPrism is still indexing!!!
So thanks for the deleting image suggestions but I will have to continue tomorrow.

[lastzero]

Temporarily disabling TensorFlow won't remove existing Labels and People. However, it might help us find what exactly is causing this. Another thing you can try is to use the "imaging" image library instead of the newly added libvips:
https://docs.photoprism.app/getting-started/config-options/#preview-images

[Bananas-Are-Yellow]

I have the exact same problem with my Synology DS1517+ (DSM version: DSM 7.2-64570 Update 3) and docker (what Synology calls the Container Manager). I installed PhotoPrism last night, so it's the latest version. It ran for many hours before I got the error:

Fatal glibc error: cannot get entropy for arc4random

My NAS is also using the same kernel as the OP:

$ uname -a
Linux diskstation 3.10.108 #64570 SMP Fri Jul 14 01:07:53 CST 2023 x86_64 GNU/Linux synology_avoton_1517+

I hope you guys can fix this.