I am trying to make a nightly offsite backup using rsync. There is a folder /media/raid1/backup that is to be uploaded to a different server every night using a cron job running as the user server_sync which exists on both boxes.
This is the rsync command:
#!/bin/bash
rsync -axz -e "ssh -p 222" --delete /media/raid1/backup/ filch:/backup_offsite --partial-dir /backup_offsite/.rsync_partial --exclude '*.old' --exclude 'old' --stop-at 06:00
When run interactively using sudo -H -u server_sync rsync... the command works just fine. The cron job, however, fails every night with this message (user names masked):
X-Cron-Env: <SHELL=/bin/sh>
X-Cron-Env: <HOME=/home/server_sync>
X-Cron-Env: <PATH=/usr/bin:/bin>
X-Cron-Env: <LOGNAME=server_sync>
Date: Sun, 12 Aug 2018 03:00:11 +0200 (CEST)
rsync: opendir "/media/raid1/backup/j****" failed: Permission denied (13)
rsync: opendir "/media/raid1/backup/m*******" failed: Permission denied (13)
rsync: opendir "/media/raid1/backup/r***" failed: Permission denied (13)
IO error encountered -- skipping file deletion
rsync error: some files/attrs were not transferred (see previous errors) (code 23) at main.c(1196) [sender=3.1.2]
The following are the permissions of the file to backup:
# ls -al /media/raid1/backup/
total 316
drwxr-s--- 5 root backup_sync .
drwxr-xr-x 19 root root ..
drwxr-s--- 3 j**** server_sync j****
drwxr-s--- 2 m******* server_sync m*******
drwxr-s--- 3 r*** server_sync r***
The server_sync user is in both groups:
# id server_sync
uid=124(server_sync) gid=131(server_sync) groups=131(server_sync),129(backup_sync),130(media)
I'm sure I am missing something with either the file permissions or the permissions / group memberships I have when sudo-ing vs when in cron mode – can anybody point it out?
Best Answer
It seems that cron doesn't set up the additional groups. Run the id command from a cron job and write the result to a file, or to stdout and get it by mail.