Hi,

Using dsync to backup my users' mailboxes (dovecot 2.2.10 on both sides), I sometimes encounter the following issue.

Below is the output of: dsync -Dvf -u "user" -R backup ssh root@server.domain.tld dsync -u "user"

doveadm(root): Debug: Loading modules from directory: /usr/local/lib/dovecot/doveadm doveadm(root): Debug: Skipping module doveadm_acl_plugin, because dlopen() failed: /usr/local/lib/dovecot/doveadm/lib10_doveadm_acl_plugin.so: undefined symbol: acl_user_module (this is usually intentional, so just ignore this message) doveadm(root): Debug: Skipping module doveadm_expire_plugin, because dlopen() failed: /usr/local/lib/dovecot/doveadm/lib10_doveadm_expire_plugin.so: undefined symbol: expire_set_lookup (this is usually intentional, so just ignore this message) doveadm(root): Debug: Skipping module doveadm_quota_plugin, because dlopen() failed: /usr/local/lib/dovecot/doveadm/lib10_doveadm_quota_plugin.so: undefined symbol: quota_user_module (this is usually intentional, so just ignore this message) doveadm(root): Debug: Module loaded: /usr/local/lib/dovecot/doveadm/lib10_doveadm_sieve_plugin.so doveadm(root): Debug: Skipping module doveadm_fts_plugin, because dlopen() failed: /usr/local/lib/dovecot/doveadm/lib20_doveadm_fts_plugin.so: undefined symbol: fts_list_backend (this is usually intentional, so just ignore this message) doveadm(user): Debug: Effective uid=495, gid=495, home=/srv/mail/u/user doveadm(user): Debug: Namespace inbox: type=private, prefix=, sep=, inbox=yes, hidden=no, list=yes, subscriptions=yes location=sdbox:/srv/mail/u/user doveadm(user): Debug: fs: root=/srv/mail/u/user, index=, indexpvt=, control=, inbox=, alt= doveadm(user): Debug: Namespace : Using permissions from /srv/mail/u/user: mode=0700 gid=default dsync-local(user): Debug: brain M: in state=master_recv_handshake dsync-local(user): Debug: brain M: out state=send_mailbox_tree changed=1 dsync-local(user): Debug: brain M: in state=send_mailbox_tree dsync-local(user): Debug: brain M: out state=send_mailbox_tree_deletes changed=1 dsync-local(user): Debug: brain M: in state=send_mailbox_tree_deletes dsync-local(user): Debug: brain M: out state=recv_mailbox_tree changed=1 dsync-local(user): Debug: brain M: in state=recv_mailbox_tree dsync-local(user): Debug: brain M: out state=recv_mailbox_tree changed=0 dsync-local(user): Debug: brain M: in state=recv_mailbox_tree dsync-local(user): Debug: brain M: out state=recv_mailbox_tree_deletes changed=1 dsync-local(user): Debug: brain M: in state=recv_mailbox_tree_deletes dsync-local(user): Debug: brain M: out state=recv_mailbox_tree_deletes changed=0 dsync-remote(user): Panic: file dsync-brain-mailbox-tree-sync.c: line 111 (dsync_brain_mailbox_tree_sync_change): assertion failed: (brain->no_backup_overwrite) dsync-remote(user): Error: Raw backtrace: /usr/local/lib/dovecot/libdovecot.so.0(+0x6889a) [0x7f1e89ee889a] -> /usr/local/lib/dovecot/libdovecot.so.0(default_fatal_handler+0x32) [0x7f1e89ee89a2] -> /usr/local/lib/dovecot/libdovecot.so.0(i_error+0) [0x7f1e89ea21cf] -> dsyn(dsync_brain_mailbox_tree_sync_change+0x3c6) [0x42e046] -> dsyn(dsync_brain_recv_mailbox_tree_deletes+0x12a) [0x42d30a] -> dsyn(dsync_brain_run+0x2e6) [0x42ac96] -> dsyn() [0x42b5f0] -> dsyn() [0x43d740] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_call_io+0x36) [0x7f1e89ef8336] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0xa7) [0x7f1e89ef93a7] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_run+0x38) [0x7f1e89ef82a8] -> dsyn() [0x427fd1] -> dsyn() [0x411c97] -> dsyn(doveadm_mail_try_run+0x238) [0x4120a8] -> dsyn(main+0x3d1) [0x41aaa1] -> /lib64/libc.so.6(__libc_start_main+0xfd) [0x7f1e89b0ad1d] -> dsyn() [0x411419] dsync-local(user): Debug: brain M: in state=recv_mailbox_tree_deletes dsync-local(user): Error: read(server.domain.tld) failed: EOF dsync-local(user): Debug: brain M: out state=recv_mailbox_tree_deletes changed=0 dsync-local(user): Error: Remote command returned error 255

Regards, Gilles