I'm running Dovecot 2.3.4 with Single Instance Storage (SIS) and zlib and I am frequently seeing errors where files are missing in the attachments directory even though the zipped file in the hash directory is actually there.  This appears not to have been an issue in Dovecot 2.3.1 Requested output of the server below.

The error looks like this in the log

Dec 18 08:58:58 dovecot01 dovecot: imap(username)<3692><RKnPGEh9fC3AqAAB>: Error: Mailbox INBOX/FOLDER: UID=41: read(attachments-connector(zlib(/usr/home/vmail/mail/username//mdbox/storage/m.411))) failed: read(/usr/home/vmail/attachments/91/08/91085773a0774909207852b8f9c98dbe22fe5a31-e88ba0276aae135cd2050000d09efc50[base64:19 b/l]) failed: open(/usr/home/vmail/attachments/91/08/91085773a0774909207852b8f9c98dbe22fe5a31-e88ba0276aae135cd2050000d09efc50) failed: No such file or directory (FETCH BODY[])

I'm also seeing errors when replication fails

dovecot: dsync-local(username)<bzg3MqjhGFxmFwAAzRvpBw>: Error: dsync(servername): read(attachments-connector(zlib(/usr/home/vmail/mail/username//mdbox/storage/m.413))) failed: read(/usr/home/vmail/attachments/45/42/4542dcf385f6b4a4dc8752b96db1d7ad8a8023d5-ac735007f6bd135c93440100cd1be907[base64:19 b/l]) failed: open(/usr/home/vmail/attachments/45/42/4542dcf385f6b4a4dc8752b96db1d7ad8a8023d5-ac735007f6bd135c93440100cd1be907) failed: No such file or directory (last sent=mail, last recv=mail (EOL))

It is not the case that every replication fail has a corresponding imap access fail.

I am running Dovecot 2.3.4 on FreeBSD11.2 and I did not see this error on Dovecot 2.3.1 FreeBSD 10.4.  Both installs had the same configuration for Dovecot.  Both installs were made from source code and not packages (as the need for the non standard fts and mysql options).

During my testing I had the 2.3.1 install receive mail and replicate to the 2.3.4 and that was working fine (except for tcp connection issues which I saw was fixed in the changelog).

Unfortunately having gone into testing with real account and mail being sent to the 2.3.4 install I'm seeing the above errors.

My clients are using Thunderbird on desktops and Roundcube for webmail.

My users report they can see the e-mails fine in their webmail (Roundcube) and only Thunderbird is giving issues.  I admit I don't know how this can be the case as both systems use the same account details.

In everycase so far there is a file in the hashes directory I have hand crafted the missing file (i.e. link) using ln and this restores access in Thunderbird.

Clearly this is an big issue for my install and I'd appreciate any help!

At the moment it looks like my course will be to try and script creation (recreation?) of the links from the error logs (I've seen people talking about this online) but that isn't really what I'm after.

DOVECOT CONFIG

2.3.4 (0ecbaf23d): /usr/local/etc/dovecot/dovecot.conf

Pigeonhole version 0.5.4 (60b0f48d)

OS: FreeBSD 11.2-RELEASE-p5 amd64

Hostname: dovecot01.cwa.uk.com

dict { acl = mysql:/usr/local/etc/dovecot/dovecot-dict-sql.conf.ext } disable_plaintext_auth = no doveadm_password = # hidden, use -P to show it first_valid_uid = 145 last_valid_uid = 145 mail_access_groups = mail mail_attachment_dir = /usr/home/vmail/attachments mail_attachment_min_size = 64 k mail_gid = vmail mail_location = mdbox:~/mdbox:INDEX=/indexdisk/indexes/%n mail_plugins = " fts fts_solr acl zlib notify replication" mail_privileged_group = mail mail_uid = vmail managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date index ihave duplicate mime foreverypart extracttext namespace { list = yes location = mdbox:%%h/mdbox:INDEXPVT=~/mdbox/shared/%%n prefix = shared/%%n/ separator = / subscriptions = yes type = shared } namespace inbox { inbox = yes location = mailbox Drafts { auto = subscribe special_use = \Drafts } mailbox Junk { auto = subscribe special_use = \Junk } mailbox Sent { auto = subscribe special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { auto = subscribe special_use = \Trash } prefix = type = private } passdb { args = /usr/local/etc/dovecot/dovecot-sql.conf.ext driver = sql } plugin { acl = vfile acl_shared_dict = proxy::acl fts = solr fts_autoindex = yes fts_solr = url=http://localhost:8983/solr/dovecot/ mail_replica = tcp:192.168.0.138:12345 replication_dsync_parameters = -d -l 30 -U sieve = ~/.dovecot.sieve sieve_dir = ~/sieve sieve_duplicate_default_period = 1h sieve_duplicate_max_period = 1d sieve_global_dir = /usr/home/vmail/sieve/global/ sieve_global_path = /usr/home/vmail/default.sieve sieve_vacation_default_period = 1d zlib_save = gz zlib_save_level = 6 } protocols = imap sieve service aggregator { fifo_listener replication-notify-fifo { user = vmail } unix_listener replication-notify { user = vmail } } service auth { unix_listener auth-userdb { mode = 0777 } } service dict { unix_listener dict { mode = 0600 user = vmail } } service doveadm { inet_listener { port = 12345 } } service replicator { process_min_avail = 1 unix_listener replicator-doveadm { mode = 0600 user = vmail } } ssl = no userdb { driver = prefetch } userdb { args = /usr/local/etc/dovecot/dovecot-sql.conf.ext driver = sql } protocol lda { mail_plugins = " fts fts_solr acl zlib notify replication sieve" submission_host = 192.168.0.1:25 } protocol imap { mail_plugins = " fts fts_solr acl zlib notify replication imap_acl imap_zlib" }