backupd and sync_client IOERROR

[Marco]

Hello,

  I'm trying to configure backupd in rolling mode as a final setup. 
Running a first backup on few users

sync_client -A -n bck -z -v -v

after a while the process die with:

cyrus/sync_client[9540]: MESSAGE received NO response: 
IMAP_PROTOCOL_ERROR Protocol error
cyrus/sync_client[9540]: do_folders(): update failed: 
example.com!user.utente^archivista 'Bad protocol'
cyrus/sync_client[9540]: IOERROR: do_user_main: Bad protocol for 
utente.archivista at example.com to [no channel] (tst-msg03-bck.example.com)
Error from do_user(utente.archivista at example.com): bailing out!
cyrus/sync_client[9540]: Error in 
do_user(utente.archivista at example.com): bailing out!

The backupd host doesn't complain:

2020-06-18T11:50:30.528584+02:00 tst-msg03-bck backupd[1308172]: 
creating sql_db 
/var/spool/cyr_backup/u/utente.archivista at example.com_cxlsmX.index
2020-06-18T11:56:44.971042+02:00 tst-msg03-bck backupd[1308172]: login: 
tst-msg03.example.com [10.102.42.168] cyr_backup LOGIN User logged in

So I repeated the same command, but with less verbosity:

sync_client -A -n bck -z -v

and it worked well, without errors. Uhm...

Maybe, before to run the first initial backup (sync_client -A), do I 
have to stop the sync_client already working in rolling mode?

http://www.cyrusimap.org/imap/reference/admin/backups.html says "Update 
cyrus.conf(5) to add a sync_client(8) invocation to the SERVICES section 
specifying (at least) the -r and -n channel options.". Really maybe you 
intend START. In SERVICE I need to specify a listen too, this is not 
very clear to me.


Around of backupd I would ask two other questions:

1) The backupd host always claims this:

backupd[1309970]: DBERROR: reading /var/lib/imap/db/skipstamp, assuming 
the worst: No such file or directory

Could you tell me how to fix that DBERROR too?

2) Is there a way to delete a user from backupd host?

Thank you very much
Cheers

Marco



master imapd.conf contains:

bck_sync_host: tst-msg03-bck.example.com
bck_sync_port: csync
bck_sync_authname: cyr_backup
bck_sync_password: *********
bck_sync_log: 1
bck_sync_repeat_interval: 1m
bck_sync_try_imap: no
force_sasl_client_mech: PLAIN, LOGIN
sync_log: on
sync_log_channels: squatter, bck
========================================

master cyrus.conf:
START {
   # do not delete this entry!
   recover       cmd="ctl_cyrusdb -r"

   # backup
   backup        cmd="/sbin/sync_client -r -n bck -z"
}

==========================================

backupd full imapd.conf is:

# Configuration directory
configdirectory: /var/lib/imap
temp_path: /run/cyrus

# Directories for proc and lock files
proc_path: /run/cyrus/proc
mboxname_lockpath: /run/cyrus/lock


# One year backup
backup_retention: 365

backuppartition-name: /var/spool/cyr_backup

# Maybe to improve:
backup_compact_minsize: 0
backup_compact_maxsize: 0
backup_compact_work_threshold: 1

admins: cyr_backup

###################################################################
## User Authentication settings
###################################################################

# Allow plaintext logins by default (SASL PLAIN)
allowplaintext: yes

###################################################################
## SASL library options (these are handled directly by the SASL
## libraries, refer to SASL documentation for an up-to-date list of
## these)
###################################################################

# The mechanism(s) used by the server to verify plaintext passwords.
# Possible values are "saslauthd", "auxprop", "pwcheck" and
# "alwaystrue".  They are tried in order, you can specify more than one,
# separated by spaces.
sasl_pwcheck_method: saslauthd

# If enabled, the SASL library will automatically create authentication
# secrets when given a plaintext password. Refer to SASL documentation
sasl_auto_transition: no

=======================================================================

backupd full cyrus.conf is:

SERVICES {
     # backupd is probably the only service entry your backup server needs
     backupd cmd="backupd" listen="csync" proto="tcp4" prefork=0
}

EVENTS {
     # this is required
     checkpoint cmd="ctl_cyrusdb -c" period=30

     # arrange for compact to run at some interval
     compact cmd="ctl_backups compact -A" at=0400
}
===========================================================================