@james it still happens sometimes. I did more investigation in the log. It says in between it couldn't find the file ("Old backup not found").
Jan 14 05:26:29 box:storage/s3 Upload progress: {"loaded":40692513140,"part":304,"Key":"snapshot/app_APP_UUID_01.tar.gz.enc","Bucket":"ACME-BACKUP"}
Jan 14 05:47:09 box:storage/s3 Upload finished. {"$metadata":{"httpStatusCode":200,"requestId":"REQUEST_ID_01-ACCOUNT_01-REGION_01","attempts":3,"totalRetryDelay":40000},"Bucket":"ACME-BACKUP","ETag":"\"\"","Key":"snapshot/app_APP_UUID_01.tar.gz.enc","Location":"S3_ENDPOINT_01/ACME-BACKUP/snapshot/app_APP_UUID_01.tar.gz.enc"}
Jan 14 05:47:09 box:backuptask upload: path snapshot/app_APP_UUID_01.tar.gz.enc site SITE_UUID_01 uploaded: {"fileCount":11571,"size":40692513140,"transferred":40692513140}
Jan 14 05:47:09 box:tasks updating task TASK_ID_01 with: {"percent":75.1935483870967,"message":"Uploading integrity information to snapshot/app_APP_UUID_01.tar.gz.enc.backupinfo (REGISTRY.DOMAIN.TLD)"}
Jan 14 05:47:10 box:storage/s3 Upload progress: {"loaded":146,"total":146,"part":1,"Key":"snapshot/app_APP_UUID_01.tar.gz.enc.backupinfo","Bucket":"ACME-BACKUP"}
Jan 14 05:47:10 box:storage/s3 Upload finished. {"$metadata":{"httpStatusCode":200,"requestId":"REQUEST_ID_02-ACCOUNT_02-REGION_01","attempts":1,"totalRetryDelay":0},"ETag":"\"ETAG_01\"","Bucket":"ACME-BACKUP","Key":"snapshot/app_APP_UUID_01.tar.gz.enc.backupinfo","Location":"https://ACME-BACKUP.s3.REGION_01.ionoscloud.com/snapshot/app_APP_UUID_01.tar.gz.enc.backupinfo"}
Jan 14 05:47:10 box:backupupload upload completed. error: null
Jan 14 05:47:10 box:backuptask runBackupUpload: result - {"result":{"stats":{"fileCount":11571,"size":40692513140,"transferred":40692513140},"integrity":{"signature":"SIGNATURE_01"}}}
Jan 14 05:47:10 box:backuptask uploadAppSnapshot: REGISTRY.DOMAIN.TLD uploaded to snapshot/app_APP_UUID_01.tar.gz.enc. 4202.695 seconds
Jan 14 05:47:10 box:backuptask backupAppWithTag: rotating REGISTRY.DOMAIN.TLD snapshot of SITE_UUID_01 to path 2026-01-14-030000-896/app_REGISTRY.DOMAIN.TLD_VERSION_01.tar.gz.enc
Jan 14 05:47:10 box:tasks updating task TASK_ID_01 with: {"percent":75.1935483870967,"message":"Copying (multipart) snapshot/app_APP_UUID_01.tar.gz.enc"}
Jan 14 05:47:10 box:tasks updating task TASK_ID_01 with: {"percent":75.1935483870967,"message":"Copying part 1 - ACME-BACKUP/snapshot/app_APP_UUID_01.tar.gz.enc bytes=0-1073741823"}
Jan 14 05:47:10 box:tasks updating task TASK_ID_01 with: {"percent":75.1935483870967,"message":"Copying part 2 - ACME-BACKUP/snapshot/app_APP_UUID_01.tar.gz.enc bytes=1073741824-2147483647"}
Jan 14 05:47:10 box:tasks updating task TASK_ID_01 with: {"percent":75.1935483870967,"message":"Copying part 3 - ACME-BACKUP/snapshot/app_APP_UUID_01.tar.gz.enc bytes=2147483648-3221225471"}
Jan 14 05:47:10 box:tasks updating task TASK_ID_01 with: {"percent":75.1935483870967,"message":"Aborting multipart copy of snapshot/app_APP_UUID_01.tar.gz.enc"}
Jan 14 05:47:10 box:storage/s3 copy: s3 copy error when copying snapshot/app_APP_UUID_01.tar.gz.enc: NoSuchKey: UnknownError
Jan 14 05:47:10 box:backuptask copy: copy to 2026-01-14-030000-896/app_REGISTRY.DOMAIN.TLD_VERSION_01.tar.gz.enc errored. error: Old backup not found: snapshot/app_APP_UUID_01.tar.gz.enc
Jan 14 05:47:10 box:backuptask fullBackup: app REGISTRY.DOMAIN.TLD backup finished. Took 4203.103 seconds
Jan 14 05:47:10 box:locks write: current locks: {"full_backup_task_SITE_UUID_01":null}
Jan 14 05:47:10 box:locks release: app_backup_APP_UUID_01
Jan 14 05:47:10 box:tasks setCompleted - TASK_ID_01: {"result":null,"error":{"message":"Old backup not found: snapshot/app_APP_UUID_01.tar.gz.enc","reason":"Not found"},"percent":100}
Jan 14 05:47:10 box:tasks updating task TASK_ID_01 with: {"completed":true,"result":null,"error":{"message":"Old backup not found: snapshot/app_APP_UUID_01.tar.gz.enc","reason":"Not found"},"percent":100}
Jan 14 05:47:10 box:taskworker Task took 6429.474 seconds
Jan 14 05:47:10 BoxError: Old backup not found: snapshot/app_APP_UUID_01.tar.gz.enc
Jan 14 05:47:10 at throwError (/home/yellowtent/box/src/storage/s3.js:387:49)
Jan 14 05:47:10 at copyInternal (/home/yellowtent/box/src/storage/s3.js:454:16)
Jan 14 05:47:10 at process.processTicksAndRejections (node:internal/process/task_queues:105:5)
Jan 14 05:47:10 at async Object.copy (/home/yellowtent/box/src/storage/s3.js:488:12)
Jan 14 05:47:10 at async Object.copy (/home/yellowtent/box/src/backupformat/tgz.js:282:5)
Jan 14 05:47:10 Exiting with code 0
I checked the bucket and can see its still there:
app_APP_UUID_01.tar.gz.enc 37.90 GB 14.1.2026, 05:36:49
app_APP_UUID_01.tar.gz.enc.backupinfo 146 bytes 14.1.2026, 05:47:09
Please also check the timestamps.
Whats causing the the process is not finding the file and stopping the process?